diff --git a/ale_linters/ada/gcc.vim b/ale_linters/ada/gcc.vim
index 7b0c4809..87496b81 100644
--- a/ale_linters/ada/gcc.vim
+++ b/ale_linters/ada/gcc.vim
@@ -48,7 +48,7 @@ endfunction
 call ale#linter#Define('ada', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('ada_gcc_executable'),
-\   'command_callback': 'ale_linters#ada#gcc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'ada_gcc_executable')},
+\   'command': function('ale_linters#ada#gcc#GetCommand'),
 \   'callback': 'ale_linters#ada#gcc#Handle',
 \})
diff --git a/ale_linters/ansible/ansible_lint.vim b/ale_linters/ansible/ansible_lint.vim
index 99fff6c3..c4affa31 100644
--- a/ale_linters/ansible/ansible_lint.vim
+++ b/ale_linters/ansible/ansible_lint.vim
@@ -50,7 +50,7 @@ endfunction
 call ale#linter#Define('ansible', {
 \   'name': 'ansible_lint',
 \   'aliases': ['ansible', 'ansible-lint'],
-\   'executable_callback': 'ale_linters#ansible#ansible_lint#GetExecutable',
+\   'executable': function('ale_linters#ansible#ansible_lint#GetExecutable'),
 \   'command': '%e -p %t',
 \   'callback': 'ale_linters#ansible#ansible_lint#Handle',
 \})
diff --git a/ale_linters/asciidoc/textlint.vim b/ale_linters/asciidoc/textlint.vim
index 757718b9..308a3a29 100644
--- a/ale_linters/asciidoc/textlint.vim
+++ b/ale_linters/asciidoc/textlint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('asciidoc', {
 \   'name': 'textlint',
-\   'executable_callback': 'ale#handlers#textlint#GetExecutable',
-\   'command_callback': 'ale#handlers#textlint#GetCommand',
+\   'executable': function('ale#handlers#textlint#GetExecutable'),
+\   'command': function('ale#handlers#textlint#GetCommand'),
 \   'callback': 'ale#handlers#textlint#HandleTextlintOutput',
 \})
diff --git a/ale_linters/asm/gcc.vim b/ale_linters/asm/gcc.vim
index fdd0ee83..72b293c0 100644
--- a/ale_linters/asm/gcc.vim
+++ b/ale_linters/asm/gcc.vim
@@ -28,7 +28,7 @@ endfunction
 call ale#linter#Define('asm', {
 \    'name': 'gcc',
 \    'output_stream': 'stderr',
-\    'executable_callback': ale#VarFunc('asm_gcc_executable'),
-\    'command_callback': 'ale_linters#asm#gcc#GetCommand',
+\    'executable': {b -> ale#Var(b, 'asm_gcc_executable')},
+\    'command': function('ale_linters#asm#gcc#GetCommand'),
 \    'callback': 'ale_linters#asm#gcc#Handle',
 \})
diff --git a/ale_linters/awk/gawk.vim b/ale_linters/awk/gawk.vim
index eb92e45e..f795c57d 100644
--- a/ale_linters/awk/gawk.vim
+++ b/ale_linters/awk/gawk.vim
@@ -15,8 +15,8 @@ endfunction
 
 call ale#linter#Define('awk', {
 \   'name': 'gawk',
-\   'executable_callback': ale#VarFunc('awk_gawk_executable'),
-\   'command_callback': 'ale_linters#awk#gawk#GetCommand',
+\   'executable': {b -> ale#Var(b, 'awk_gawk_executable')},
+\   'command': function('ale_linters#awk#gawk#GetCommand'),
 \   'callback': 'ale#handlers#gawk#HandleGawkFormat',
 \   'output_stream': 'both'
 \})
diff --git a/ale_linters/bib/bibclean.vim b/ale_linters/bib/bibclean.vim
index 1c6b55d0..9056a9c3 100644
--- a/ale_linters/bib/bibclean.vim
+++ b/ale_linters/bib/bibclean.vim
@@ -68,8 +68,8 @@ endfunction
 
 call ale#linter#Define('bib', {
 \   'name': 'bibclean',
-\   'executable_callback': ale#VarFunc('bib_bibclean_executable'),
-\   'command_callback': 'ale_linters#bib#bibclean#GetCommand',
+\   'executable': {b -> ale#Var(b, 'bib_bibclean_executable')},
+\   'command': function('ale_linters#bib#bibclean#GetCommand'),
 \   'output_stream': 'stderr',
 \   'callback': 'ale_linters#bib#bibclean#Handle',
 \})
diff --git a/ale_linters/c/ccls.vim b/ale_linters/c/ccls.vim
index 5dc2339f..9e3dafe9 100644
--- a/ale_linters/c/ccls.vim
+++ b/ale_linters/c/ccls.vim
@@ -7,8 +7,8 @@ call ale#Set('c_ccls_init_options', {})
 call ale#linter#Define('c', {
 \   'name': 'ccls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('c_ccls_executable'),
+\   'executable': {b -> ale#Var(b, 'c_ccls_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale#handlers#ccls#GetProjectRoot',
-\   'initialization_options_callback':ale#VarFunc('c_ccls_init_options'),
+\   'project_root': function('ale#handlers#ccls#GetProjectRoot'),
+\   'initialization_options': {b -> ale#Var(b, 'c_ccls_init_options')},
 \})
diff --git a/ale_linters/c/clang.vim b/ale_linters/c/clang.vim
index f1bd675b..5b243bfe 100644
--- a/ale_linters/c/clang.vim
+++ b/ale_linters/c/clang.vim
@@ -18,7 +18,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'clang',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('c_clang_executable'),
+\   'executable': {b -> ale#Var(b, 'c_clang_executable')},
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#c#clang#GetCommand'}
diff --git a/ale_linters/c/clangd.vim b/ale_linters/c/clangd.vim
index 6cad601a..918eadcc 100644
--- a/ale_linters/c/clangd.vim
+++ b/ale_linters/c/clangd.vim
@@ -17,7 +17,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'clangd',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('c_clangd_executable'),
-\   'command_callback': 'ale_linters#c#clangd#GetCommand',
-\   'project_root_callback': 'ale_linters#c#clangd#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'c_clangd_executable')},
+\   'command': function('ale_linters#c#clangd#GetCommand'),
+\   'project_root': function('ale_linters#c#clangd#GetProjectRoot'),
 \})
diff --git a/ale_linters/c/clangtidy.vim b/ale_linters/c/clangtidy.vim
index 4f334655..6484f8af 100644
--- a/ale_linters/c/clangtidy.vim
+++ b/ale_linters/c/clangtidy.vim
@@ -35,8 +35,8 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'clangtidy',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('c_clangtidy_executable'),
-\   'command_callback': 'ale_linters#c#clangtidy#GetCommand',
+\   'executable': {b -> ale#Var(b, 'c_clangtidy_executable')},
+\   'command': function('ale_linters#c#clangtidy#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/c/cppcheck.vim b/ale_linters/c/cppcheck.vim
index 5e8c7936..851f9f11 100644
--- a/ale_linters/c/cppcheck.vim
+++ b/ale_linters/c/cppcheck.vim
@@ -28,7 +28,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'cppcheck',
 \   'output_stream': 'both',
-\   'executable_callback': ale#VarFunc('c_cppcheck_executable'),
-\   'command_callback': 'ale_linters#c#cppcheck#GetCommand',
+\   'executable': {b -> ale#Var(b, 'c_cppcheck_executable')},
+\   'command': function('ale_linters#c#cppcheck#GetCommand'),
 \   'callback': 'ale#handlers#cppcheck#HandleCppCheckFormat',
 \})
diff --git a/ale_linters/c/cquery.vim b/ale_linters/c/cquery.vim
index a20782a2..d2be9cd9 100644
--- a/ale_linters/c/cquery.vim
+++ b/ale_linters/c/cquery.vim
@@ -21,8 +21,8 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'cquery',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('c_cquery_executable'),
+\   'executable': {b -> ale#Var(b, 'c_cquery_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale_linters#c#cquery#GetProjectRoot',
-\   'initialization_options_callback': 'ale_linters#c#cquery#GetInitializationOptions',
+\   'project_root': function('ale_linters#c#cquery#GetProjectRoot'),
+\   'initialization_options': function('ale_linters#c#cquery#GetInitializationOptions'),
 \})
diff --git a/ale_linters/c/flawfinder.vim b/ale_linters/c/flawfinder.vim
index 94104141..53c36716 100644
--- a/ale_linters/c/flawfinder.vim
+++ b/ale_linters/c/flawfinder.vim
@@ -19,7 +19,7 @@ endfunction
 call ale#linter#Define('c', {
 \  'name': 'flawfinder',
 \  'output_stream': 'stdout',
-\  'executable_callback': ale#VarFunc('c_flawfinder_executable'),
-\  'command_callback': 'ale_linters#c#flawfinder#GetCommand',
+\  'executable': {b -> ale#Var(b, 'c_flawfinder_executable')},
+\  'command': function('ale_linters#c#flawfinder#GetCommand'),
 \  'callback': 'ale#handlers#flawfinder#HandleFlawfinderFormat',
 \})
diff --git a/ale_linters/c/gcc.vim b/ale_linters/c/gcc.vim
index 60ecb712..ccb1912b 100644
--- a/ale_linters/c/gcc.vim
+++ b/ale_linters/c/gcc.vim
@@ -18,7 +18,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('c_gcc_executable'),
+\   'executable': {b -> ale#Var(b, 'c_gcc_executable')},
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#c#gcc#GetCommand'}
diff --git a/ale_linters/chef/foodcritic.vim b/ale_linters/chef/foodcritic.vim
index c86336d6..48beba75 100644
--- a/ale_linters/chef/foodcritic.vim
+++ b/ale_linters/chef/foodcritic.vim
@@ -34,8 +34,8 @@ endfunction
 
 call ale#linter#Define('chef', {
 \   'name': 'foodcritic',
-\   'executable_callback': ale#VarFunc('chef_foodcritic_executable'),
-\   'command_callback': 'ale_linters#chef#foodcritic#GetCommand',
+\   'executable': {b -> ale#Var(b, 'chef_foodcritic_executable')},
+\   'command': function('ale_linters#chef#foodcritic#GetCommand'),
 \   'callback': 'ale_linters#chef#foodcritic#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/cmake/cmakelint.vim b/ale_linters/cmake/cmakelint.vim
index 78676518..d955a265 100644
--- a/ale_linters/cmake/cmakelint.vim
+++ b/ale_linters/cmake/cmakelint.vim
@@ -18,7 +18,7 @@ endfunction
 
 call ale#linter#Define('cmake', {
 \   'name': 'cmakelint',
-\   'executable_callback': 'ale_linters#cmake#cmakelint#Executable',
-\   'command_callback': 'ale_linters#cmake#cmakelint#Command',
+\   'executable': function('ale_linters#cmake#cmakelint#Executable'),
+\   'command': function('ale_linters#cmake#cmakelint#Command'),
 \   'callback': 'ale#handlers#unix#HandleAsWarning',
 \})
diff --git a/ale_linters/coffee/coffee.vim b/ale_linters/coffee/coffee.vim
index f2539281..8e891639 100644
--- a/ale_linters/coffee/coffee.vim
+++ b/ale_linters/coffee/coffee.vim
@@ -16,8 +16,8 @@ endfunction
 
 call ale#linter#Define('coffee', {
 \   'name': 'coffee',
-\   'executable_callback': 'ale_linters#coffee#coffee#GetExecutable',
-\   'command_callback': 'ale_linters#coffee#coffee#GetCommand',
+\   'executable': function('ale_linters#coffee#coffee#GetExecutable'),
+\   'command': function('ale_linters#coffee#coffee#GetCommand'),
 \   'output_stream': 'stderr',
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \})
diff --git a/ale_linters/coffee/coffeelint.vim b/ale_linters/coffee/coffeelint.vim
index 6d3df353..b7c85fa7 100644
--- a/ale_linters/coffee/coffeelint.vim
+++ b/ale_linters/coffee/coffeelint.vim
@@ -37,7 +37,7 @@ endfunction
 
 call ale#linter#Define('coffee', {
 \   'name': 'coffeelint',
-\   'executable_callback': 'ale_linters#coffee#coffeelint#GetExecutable',
-\   'command_callback': 'ale_linters#coffee#coffeelint#GetCommand',
+\   'executable': function('ale_linters#coffee#coffeelint#GetExecutable'),
+\   'command': function('ale_linters#coffee#coffeelint#GetCommand'),
 \   'callback': 'ale_linters#coffee#coffeelint#Handle',
 \})
diff --git a/ale_linters/cpp/ccls.vim b/ale_linters/cpp/ccls.vim
index 501fd685..b265ff70 100644
--- a/ale_linters/cpp/ccls.vim
+++ b/ale_linters/cpp/ccls.vim
@@ -7,8 +7,8 @@ call ale#Set('cpp_ccls_init_options', {})
 call ale#linter#Define('cpp', {
 \   'name': 'ccls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('cpp_ccls_executable'),
+\   'executable': {b -> ale#Var(b, 'cpp_ccls_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale#handlers#ccls#GetProjectRoot',
-\   'initialization_options_callback': ale#VarFunc('cpp_ccls_init_options'),
+\   'project_root': function('ale#handlers#ccls#GetProjectRoot'),
+\   'initialization_options': {b -> ale#Var(b, 'cpp_ccls_init_options')},
 \})
diff --git a/ale_linters/cpp/clang.vim b/ale_linters/cpp/clang.vim
index 649c5993..5a465812 100644
--- a/ale_linters/cpp/clang.vim
+++ b/ale_linters/cpp/clang.vim
@@ -18,7 +18,7 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'clang',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cpp_clang_executable'),
+\   'executable': {b -> ale#Var(b, 'cpp_clang_executable')},
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#cpp#clang#GetCommand'},
diff --git a/ale_linters/cpp/clangcheck.vim b/ale_linters/cpp/clangcheck.vim
index c66d6702..b511a413 100644
--- a/ale_linters/cpp/clangcheck.vim
+++ b/ale_linters/cpp/clangcheck.vim
@@ -27,8 +27,8 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'clangcheck',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cpp_clangcheck_executable'),
-\   'command_callback': 'ale_linters#cpp#clangcheck#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cpp_clangcheck_executable')},
+\   'command': function('ale_linters#cpp#clangcheck#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/cpp/clangd.vim b/ale_linters/cpp/clangd.vim
index 9139f054..4a8ff4f6 100644
--- a/ale_linters/cpp/clangd.vim
+++ b/ale_linters/cpp/clangd.vim
@@ -17,7 +17,7 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'clangd',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('cpp_clangd_executable'),
-\   'command_callback': 'ale_linters#cpp#clangd#GetCommand',
-\   'project_root_callback': 'ale_linters#cpp#clangd#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'cpp_clangd_executable')},
+\   'command': function('ale_linters#cpp#clangd#GetCommand'),
+\   'project_root': function('ale_linters#cpp#clangd#GetProjectRoot'),
 \})
diff --git a/ale_linters/cpp/clangtidy.vim b/ale_linters/cpp/clangtidy.vim
index 9c3da8db..841b795f 100644
--- a/ale_linters/cpp/clangtidy.vim
+++ b/ale_linters/cpp/clangtidy.vim
@@ -29,8 +29,8 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'clangtidy',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('cpp_clangtidy_executable'),
-\   'command_callback': 'ale_linters#cpp#clangtidy#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cpp_clangtidy_executable')},
+\   'command': function('ale_linters#cpp#clangtidy#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/cpp/clazy.vim b/ale_linters/cpp/clazy.vim
index cbbd0ccf..9b29ac9a 100644
--- a/ale_linters/cpp/clazy.vim
+++ b/ale_linters/cpp/clazy.vim
@@ -25,8 +25,8 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'clazy',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cpp_clazy_executable'),
-\   'command_callback': 'ale_linters#cpp#clazy#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cpp_clazy_executable')},
+\   'command': function('ale_linters#cpp#clazy#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/cpp/cppcheck.vim b/ale_linters/cpp/cppcheck.vim
index 229d6133..5173d698 100644
--- a/ale_linters/cpp/cppcheck.vim
+++ b/ale_linters/cpp/cppcheck.vim
@@ -28,7 +28,7 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'cppcheck',
 \   'output_stream': 'both',
-\   'executable_callback': ale#VarFunc('cpp_cppcheck_executable'),
-\   'command_callback': 'ale_linters#cpp#cppcheck#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cpp_cppcheck_executable')},
+\   'command': function('ale_linters#cpp#cppcheck#GetCommand'),
 \   'callback': 'ale#handlers#cppcheck#HandleCppCheckFormat',
 \})
diff --git a/ale_linters/cpp/cpplint.vim b/ale_linters/cpp/cpplint.vim
index d135fa79..f1f6ce7f 100644
--- a/ale_linters/cpp/cpplint.vim
+++ b/ale_linters/cpp/cpplint.vim
@@ -13,8 +13,8 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'cpplint',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cpp_cpplint_executable'),
-\   'command_callback': 'ale_linters#cpp#cpplint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cpp_cpplint_executable')},
+\   'command': function('ale_linters#cpp#cpplint#GetCommand'),
 \   'callback': 'ale#handlers#cpplint#HandleCppLintFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/cpp/cquery.vim b/ale_linters/cpp/cquery.vim
index b1c81989..0dd9f6ad 100644
--- a/ale_linters/cpp/cquery.vim
+++ b/ale_linters/cpp/cquery.vim
@@ -21,8 +21,8 @@ endfunction
 call ale#linter#Define('cpp', {
 \   'name': 'cquery',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('cpp_cquery_executable'),
+\   'executable': {b -> ale#Var(b, 'cpp_cquery_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale_linters#cpp#cquery#GetProjectRoot',
-\   'initialization_options_callback': 'ale_linters#cpp#cquery#GetInitializationOptions',
+\   'project_root': function('ale_linters#cpp#cquery#GetProjectRoot'),
+\   'initialization_options': function('ale_linters#cpp#cquery#GetInitializationOptions'),
 \})
diff --git a/ale_linters/cpp/flawfinder.vim b/ale_linters/cpp/flawfinder.vim
index 0a966604..5bfdea22 100644
--- a/ale_linters/cpp/flawfinder.vim
+++ b/ale_linters/cpp/flawfinder.vim
@@ -19,7 +19,7 @@ endfunction
 call ale#linter#Define('cpp', {
 \  'name': 'flawfinder',
 \  'output_stream': 'stdout',
-\  'executable_callback': ale#VarFunc('cpp_flawfinder_executable'),
-\  'command_callback': 'ale_linters#cpp#flawfinder#GetCommand',
+\  'executable': {b -> ale#Var(b, 'cpp_flawfinder_executable')},
+\  'command': function('ale_linters#cpp#flawfinder#GetCommand'),
 \  'callback': 'ale#handlers#flawfinder#HandleFlawfinderFormat',
 \})
diff --git a/ale_linters/cpp/gcc.vim b/ale_linters/cpp/gcc.vim
index 9935b0bb..831620d5 100644
--- a/ale_linters/cpp/gcc.vim
+++ b/ale_linters/cpp/gcc.vim
@@ -19,7 +19,7 @@ call ale#linter#Define('cpp', {
 \   'name': 'gcc',
 \   'aliases': ['g++'],
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cpp_gcc_executable'),
+\   'executable': {b -> ale#Var(b, 'cpp_gcc_executable')},
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#cpp#gcc#GetCommand'},
diff --git a/ale_linters/crystal/ameba.vim b/ale_linters/crystal/ameba.vim
index a1bf9c1d..5dfc7f45 100644
--- a/ale_linters/crystal/ameba.vim
+++ b/ale_linters/crystal/ameba.vim
@@ -50,8 +50,8 @@ endfunction
 
 call ale#linter#Define('crystal', {
 \   'name': 'ameba',
-\   'executable_callback': ale#VarFunc('crystal_ameba_executable'),
-\   'command_callback': 'ale_linters#crystal#ameba#GetCommand',
+\   'executable': {b -> ale#Var(b, 'crystal_ameba_executable')},
+\   'command': function('ale_linters#crystal#ameba#GetCommand'),
 \   'callback': 'ale_linters#crystal#ameba#HandleAmebaOutput',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/crystal/crystal.vim b/ale_linters/crystal/crystal.vim
index 81579d63..3c2fefb7 100644
--- a/ale_linters/crystal/crystal.vim
+++ b/ale_linters/crystal/crystal.vim
@@ -26,6 +26,6 @@ call ale#linter#Define('crystal', {
 \   'executable': 'crystal',
 \   'output_stream': 'both',
 \   'lint_file': 1,
-\   'command_callback': 'ale_linters#crystal#crystal#GetCommand',
+\   'command': function('ale_linters#crystal#crystal#GetCommand'),
 \   'callback': 'ale_linters#crystal#crystal#Handle',
 \})
diff --git a/ale_linters/cs/mcs.vim b/ale_linters/cs/mcs.vim
index 8738026d..1b373e73 100644
--- a/ale_linters/cs/mcs.vim
+++ b/ale_linters/cs/mcs.vim
@@ -32,6 +32,6 @@ call ale#linter#Define('cs',{
 \   'name': 'mcs',
 \   'output_stream': 'stderr',
 \   'executable': 'mcs',
-\   'command_callback': 'ale_linters#cs#mcs#GetCommand',
+\   'command': function('ale_linters#cs#mcs#GetCommand'),
 \   'callback': 'ale_linters#cs#mcs#Handle',
 \})
diff --git a/ale_linters/cs/mcsc.vim b/ale_linters/cs/mcsc.vim
index a169297c..dd067eba 100644
--- a/ale_linters/cs/mcsc.vim
+++ b/ale_linters/cs/mcsc.vim
@@ -75,7 +75,7 @@ call ale#linter#Define('cs',{
 \   'name': 'mcsc',
 \   'output_stream': 'stderr',
 \   'executable': 'mcs',
-\   'command_callback': 'ale_linters#cs#mcsc#GetCommand',
+\   'command': function('ale_linters#cs#mcsc#GetCommand'),
 \   'callback': 'ale_linters#cs#mcsc#Handle',
 \   'lint_file': 1
 \})
diff --git a/ale_linters/css/csslint.vim b/ale_linters/css/csslint.vim
index 98b7fdd4..50c21ce2 100644
--- a/ale_linters/css/csslint.vim
+++ b/ale_linters/css/csslint.vim
@@ -13,6 +13,6 @@ endfunction
 call ale#linter#Define('css', {
 \   'name': 'csslint',
 \   'executable': 'csslint',
-\   'command_callback': 'ale_linters#css#csslint#GetCommand',
+\   'command': function('ale_linters#css#csslint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleCSSLintFormat',
 \})
diff --git a/ale_linters/css/stylelint.vim b/ale_linters/css/stylelint.vim
index 6f8bef68..38cb0e0b 100644
--- a/ale_linters/css/stylelint.vim
+++ b/ale_linters/css/stylelint.vim
@@ -11,9 +11,9 @@ endfunction
 
 call ale#linter#Define('css', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('css_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'css_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
-\   'command_callback': 'ale_linters#css#stylelint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#css#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/cucumber/cucumber.vim b/ale_linters/cucumber/cucumber.vim
index e8ae09ff..0cfd815e 100644
--- a/ale_linters/cucumber/cucumber.vim
+++ b/ale_linters/cucumber/cucumber.vim
@@ -41,6 +41,6 @@ endfunction
 call ale#linter#Define('cucumber', {
 \   'name': 'cucumber',
 \   'executable': 'cucumber',
-\   'command_callback': 'ale_linters#cucumber#cucumber#GetCommand',
+\   'command': function('ale_linters#cucumber#cucumber#GetCommand'),
 \   'callback': 'ale_linters#cucumber#cucumber#Handle'
 \})
diff --git a/ale_linters/cuda/nvcc.vim b/ale_linters/cuda/nvcc.vim
index db789ff1..f3af07b6 100644
--- a/ale_linters/cuda/nvcc.vim
+++ b/ale_linters/cuda/nvcc.vim
@@ -42,8 +42,8 @@ endfunction
 call ale#linter#Define('cuda', {
 \   'name': 'nvcc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('cuda_nvcc_executable'),
-\   'command_callback': 'ale_linters#cuda#nvcc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'cuda_nvcc_executable')},
+\   'command': function('ale_linters#cuda#nvcc#GetCommand'),
 \   'callback': 'ale_linters#cuda#nvcc#HandleNVCCFormat',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/d/dls.vim b/ale_linters/d/dls.vim
index 7210d21e..78d1c152 100644
--- a/ale_linters/d/dls.vim
+++ b/ale_linters/d/dls.vim
@@ -16,7 +16,7 @@ endfunction
 call ale#linter#Define('d', {
 \   'name': 'dls',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#d#dls#GetExecutable',
-\   'command_callback': 'ale_linters#d#dls#GetExecutable',
-\   'project_root_callback': 'ale_linters#d#dls#FindProjectRoot',
+\   'executable': function('ale_linters#d#dls#GetExecutable'),
+\   'command': function('ale_linters#d#dls#GetExecutable'),
+\   'project_root': function('ale_linters#d#dls#FindProjectRoot'),
 \})
diff --git a/ale_linters/dart/dartanalyzer.vim b/ale_linters/dart/dartanalyzer.vim
index 26817df5..0a4d9742 100644
--- a/ale_linters/dart/dartanalyzer.vim
+++ b/ale_linters/dart/dartanalyzer.vim
@@ -29,8 +29,8 @@ endfunction
 
 call ale#linter#Define('dart', {
 \   'name': 'dartanalyzer',
-\   'executable_callback': ale#VarFunc('dart_dartanalyzer_executable'),
-\   'command_callback': 'ale_linters#dart#dartanalyzer#GetCommand',
+\   'executable': {b -> ale#Var(b, 'dart_dartanalyzer_executable')},
+\   'command': function('ale_linters#dart#dartanalyzer#GetCommand'),
 \   'callback': 'ale_linters#dart#dartanalyzer#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/dart/language_server.vim b/ale_linters/dart/language_server.vim
index 8e0c139b..d0e639c8 100644
--- a/ale_linters/dart/language_server.vim
+++ b/ale_linters/dart/language_server.vim
@@ -14,7 +14,7 @@ endfunction
 call ale#linter#Define('dart', {
 \   'name': 'language_server',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('dart_language_server_executable'),
+\   'executable': {b -> ale#Var(b, 'dart_language_server_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale_linters#dart#language_server#GetProjectRoot',
+\   'project_root': function('ale_linters#dart#language_server#GetProjectRoot'),
 \})
diff --git a/ale_linters/dockerfile/dockerfile_lint.vim b/ale_linters/dockerfile/dockerfile_lint.vim
index a5a846f2..95768b12 100644
--- a/ale_linters/dockerfile/dockerfile_lint.vim
+++ b/ale_linters/dockerfile/dockerfile_lint.vim
@@ -55,7 +55,7 @@ endfunction
 
 call ale#linter#Define('dockerfile', {
 \   'name': 'dockerfile_lint',
-\   'executable_callback': ale#VarFunc('dockerfile_dockerfile_lint_executable'),
-\   'command_callback': 'ale_linters#dockerfile#dockerfile_lint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'dockerfile_dockerfile_lint_executable')},
+\   'command': function('ale_linters#dockerfile#dockerfile_lint#GetCommand'),
 \   'callback': 'ale_linters#dockerfile#dockerfile_lint#Handle',
 \})
diff --git a/ale_linters/dockerfile/hadolint.vim b/ale_linters/dockerfile/hadolint.vim
index dc0f5b9e..e57cd76d 100644
--- a/ale_linters/dockerfile/hadolint.vim
+++ b/ale_linters/dockerfile/hadolint.vim
@@ -93,7 +93,7 @@ endfunction
 
 call ale#linter#Define('dockerfile', {
 \   'name': 'hadolint',
-\   'executable_callback': 'ale_linters#dockerfile#hadolint#GetExecutable',
-\   'command_callback': 'ale_linters#dockerfile#hadolint#GetCommand',
+\   'executable': function('ale_linters#dockerfile#hadolint#GetExecutable'),
+\   'command': function('ale_linters#dockerfile#hadolint#GetCommand'),
 \   'callback': 'ale_linters#dockerfile#hadolint#Handle',
 \})
diff --git a/ale_linters/elixir/credo.vim b/ale_linters/elixir/credo.vim
index d778471c..8431c0df 100644
--- a/ale_linters/elixir/credo.vim
+++ b/ale_linters/elixir/credo.vim
@@ -47,6 +47,6 @@ endfunction
 call ale#linter#Define('elixir', {
 \   'name': 'credo',
 \   'executable': 'mix',
-\   'command_callback': 'ale_linters#elixir#credo#GetCommand',
+\   'command': function('ale_linters#elixir#credo#GetCommand'),
 \   'callback': 'ale_linters#elixir#credo#Handle',
 \})
diff --git a/ale_linters/elixir/dialyxir.vim b/ale_linters/elixir/dialyxir.vim
index d28d3c70..c7da7757 100644
--- a/ale_linters/elixir/dialyxir.vim
+++ b/ale_linters/elixir/dialyxir.vim
@@ -35,7 +35,7 @@ endfunction
 call ale#linter#Define('elixir', {
 \   'name': 'dialyxir',
 \   'executable': 'mix',
-\   'command_callback': 'ale_linters#elixir#dialyxir#GetCommand',
+\   'command': function('ale_linters#elixir#dialyxir#GetCommand'),
 \   'callback': 'ale_linters#elixir#dialyxir#Handle',
 \})
 
diff --git a/ale_linters/elixir/dogma.vim b/ale_linters/elixir/dogma.vim
index dcfb6f28..1c721158 100644
--- a/ale_linters/elixir/dogma.vim
+++ b/ale_linters/elixir/dogma.vim
@@ -39,7 +39,7 @@ endfunction
 call ale#linter#Define('elixir', {
 \   'name': 'dogma',
 \   'executable': 'mix',
-\   'command_callback': 'ale_linters#elixir#dogma#GetCommand',
+\   'command': function('ale_linters#elixir#dogma#GetCommand'),
 \   'lint_file': 1,
 \   'callback': 'ale_linters#elixir#dogma#Handle',
 \})
diff --git a/ale_linters/elixir/elixir_ls.vim b/ale_linters/elixir/elixir_ls.vim
index 3b299ec6..d5db7cd0 100644
--- a/ale_linters/elixir/elixir_ls.vim
+++ b/ale_linters/elixir/elixir_ls.vim
@@ -14,8 +14,8 @@ endfunction
 call ale#linter#Define('elixir', {
 \   'name': 'elixir-ls',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#elixir#elixir_ls#GetExecutable',
-\   'command_callback': 'ale_linters#elixir#elixir_ls#GetExecutable',
-\   'project_root_callback': 'ale#handlers#elixir#FindMixUmbrellaRoot',
-\   'lsp_config_callback': ale#VarFunc('elixir_elixir_ls_config'),
+\   'executable': function('ale_linters#elixir#elixir_ls#GetExecutable'),
+\   'command': function('ale_linters#elixir#elixir_ls#GetExecutable'),
+\   'project_root': function('ale#handlers#elixir#FindMixUmbrellaRoot'),
+\   'lsp_config': {b -> ale#Var(b, 'elixir_elixir_ls_config')},
 \})
diff --git a/ale_linters/elixir/mix.vim b/ale_linters/elixir/mix.vim
index 59cfe505..abf5d0aa 100644
--- a/ale_linters/elixir/mix.vim
+++ b/ale_linters/elixir/mix.vim
@@ -46,7 +46,7 @@ endfunction
 call ale#linter#Define('elixir', {
 \   'name': 'mix',
 \   'executable': 'mix',
-\   'command_callback': 'ale_linters#elixir#mix#GetCommand',
+\   'command': function('ale_linters#elixir#mix#GetCommand'),
 \   'callback': 'ale_linters#elixir#mix#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/elm/make.vim b/ale_linters/elm/make.vim
index 190f7541..6b93257f 100644
--- a/ale_linters/elm/make.vim
+++ b/ale_linters/elm/make.vim
@@ -233,8 +233,8 @@ endfunction
 
 call ale#linter#Define('elm', {
 \   'name': 'make',
-\   'executable_callback': 'ale_linters#elm#make#GetExecutable',
+\   'executable': function('ale_linters#elm#make#GetExecutable'),
 \   'output_stream': 'both',
-\   'command_callback': 'ale_linters#elm#make#GetCommand',
+\   'command': function('ale_linters#elm#make#GetCommand'),
 \   'callback': 'ale_linters#elm#make#Handle'
 \})
diff --git a/ale_linters/erlang/erlc.vim b/ale_linters/erlang/erlc.vim
index 81ba128b..a83bacc3 100644
--- a/ale_linters/erlang/erlc.vim
+++ b/ale_linters/erlang/erlc.vim
@@ -91,6 +91,6 @@ endfunction
 call ale#linter#Define('erlang', {
 \   'name': 'erlc',
 \   'executable': 'erlc',
-\   'command_callback': 'ale_linters#erlang#erlc#GetCommand',
+\   'command': function('ale_linters#erlang#erlc#GetCommand'),
 \   'callback': 'ale_linters#erlang#erlc#Handle',
 \})
diff --git a/ale_linters/erlang/syntaxerl.vim b/ale_linters/erlang/syntaxerl.vim
index 5b679743..2b7276a1 100644
--- a/ale_linters/erlang/syntaxerl.vim
+++ b/ale_linters/erlang/syntaxerl.vim
@@ -26,7 +26,7 @@ endfunction
 
 call ale#linter#Define('erlang', {
 \   'name': 'syntaxerl',
-\   'executable_callback': ale#VarFunc('erlang_syntaxerl_executable'),
+\   'executable': {b -> ale#Var(b, 'erlang_syntaxerl_executable')},
 \   'command_chain': [
 \       {'callback': {-> '%e -h'}},
 \       {'callback': 'ale_linters#erlang#syntaxerl#GetCommand'},
diff --git a/ale_linters/eruby/erb.vim b/ale_linters/eruby/erb.vim
index 61d97032..f3438320 100644
--- a/ale_linters/eruby/erb.vim
+++ b/ale_linters/eruby/erb.vim
@@ -19,7 +19,7 @@ call ale#linter#Define('eruby', {
 \   'aliases': ['erubylint'],
 \   'executable': 'erb',
 \   'output_stream': 'stderr',
-\   'command_callback': 'ale_linters#eruby#erb#GetCommand',
+\   'command': function('ale_linters#eruby#erb#GetCommand'),
 \   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
 \})
 
diff --git a/ale_linters/eruby/erubis.vim b/ale_linters/eruby/erubis.vim
index 1ebd4a05..755c5803 100644
--- a/ale_linters/eruby/erubis.vim
+++ b/ale_linters/eruby/erubis.vim
@@ -18,6 +18,6 @@ call ale#linter#Define('eruby', {
 \   'name': 'erubis',
 \   'executable': 'erubis',
 \   'output_stream': 'stderr',
-\   'command_callback': 'ale_linters#eruby#erubis#GetCommand',
+\   'command': function('ale_linters#eruby#erubis#GetCommand'),
 \   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
 \})
diff --git a/ale_linters/eruby/ruumba.vim b/ale_linters/eruby/ruumba.vim
index 24f112e4..e68bb51d 100644
--- a/ale_linters/eruby/ruumba.vim
+++ b/ale_linters/eruby/ruumba.vim
@@ -56,7 +56,7 @@ endfunction
 
 call ale#linter#Define('eruby', {
 \   'name': 'ruumba',
-\   'executable_callback': ale#VarFunc('eruby_ruumba_executable'),
-\   'command_callback': 'ale_linters#eruby#ruumba#GetCommand',
+\   'executable': {b -> ale#Var(b, 'eruby_ruumba_executable')},
+\   'command': function('ale_linters#eruby#ruumba#GetCommand'),
 \   'callback': 'ale_linters#eruby#ruumba#Handle',
 \})
diff --git a/ale_linters/fortran/gcc.vim b/ale_linters/fortran/gcc.vim
index f1595789..6e97d6fd 100644
--- a/ale_linters/fortran/gcc.vim
+++ b/ale_linters/fortran/gcc.vim
@@ -66,7 +66,7 @@ endfunction
 call ale#linter#Define('fortran', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('fortran_gcc_executable'),
-\   'command_callback': 'ale_linters#fortran#gcc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'fortran_gcc_executable')},
+\   'command': function('ale_linters#fortran#gcc#GetCommand'),
 \   'callback': 'ale_linters#fortran#gcc#Handle',
 \})
diff --git a/ale_linters/fortran/language_server.vim b/ale_linters/fortran/language_server.vim
index 4e5f5dc4..00aa0577 100644
--- a/ale_linters/fortran/language_server.vim
+++ b/ale_linters/fortran/language_server.vim
@@ -13,7 +13,7 @@ endfunction
 call ale#linter#Define('fortran', {
 \   'name': 'language_server',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('fortran_language_server_executable'),
+\   'executable': {b -> ale#Var(b, 'fortran_language_server_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale_linters#fortran#language_server#GetProjectRoot',
+\   'project_root': function('ale_linters#fortran#language_server#GetProjectRoot'),
 \})
diff --git a/ale_linters/fuse/fusionlint.vim b/ale_linters/fuse/fusionlint.vim
index ab8f143b..ffb25d33 100644
--- a/ale_linters/fuse/fusionlint.vim
+++ b/ale_linters/fuse/fusionlint.vim
@@ -27,7 +27,7 @@ endfunction
 
 call ale#linter#Define('fuse', {
 \   'name': 'fusionlint',
-\   'executable_callback': ale#VarFunc('fuse_fusionlint_executable'),
-\   'command_callback': 'ale_linters#fuse#fusionlint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'fuse_fusionlint_executable')},
+\   'command': function('ale_linters#fuse#fusionlint#GetCommand'),
 \   'callback': 'ale_linters#fuse#fusionlint#Handle',
 \})
diff --git a/ale_linters/gitcommit/gitlint.vim b/ale_linters/gitcommit/gitlint.vim
index a9c4822d..4b9cec63 100644
--- a/ale_linters/gitcommit/gitlint.vim
+++ b/ale_linters/gitcommit/gitlint.vim
@@ -45,7 +45,7 @@ endfunction
 call ale#linter#Define('gitcommit', {
 \   'name': 'gitlint',
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale_linters#gitcommit#gitlint#GetExecutable',
-\   'command_callback': 'ale_linters#gitcommit#gitlint#GetCommand',
+\   'executable': function('ale_linters#gitcommit#gitlint#GetExecutable'),
+\   'command': function('ale_linters#gitcommit#gitlint#GetCommand'),
 \   'callback': 'ale_linters#gitcommit#gitlint#Handle',
 \})
diff --git a/ale_linters/glsl/glslang.vim b/ale_linters/glsl/glslang.vim
index d55a5e7c..bbddce90 100644
--- a/ale_linters/glsl/glslang.vim
+++ b/ale_linters/glsl/glslang.vim
@@ -34,7 +34,7 @@ endfunction
 
 call ale#linter#Define('glsl', {
 \   'name': 'glslang',
-\   'executable_callback': ale#VarFunc('glsl_glslang_executable'),
-\   'command_callback': 'ale_linters#glsl#glslang#GetCommand',
+\   'executable': {b -> ale#Var(b, 'glsl_glslang_executable')},
+\   'command': function('ale_linters#glsl#glslang#GetCommand'),
 \   'callback': 'ale_linters#glsl#glslang#Handle',
 \})
diff --git a/ale_linters/glsl/glslls.vim b/ale_linters/glsl/glslls.vim
index 8c6d9bd9..b62844c7 100644
--- a/ale_linters/glsl/glslls.vim
+++ b/ale_linters/glsl/glslls.vim
@@ -24,7 +24,7 @@ endfunction
 call ale#linter#Define('glsl', {
 \   'name': 'glslls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('glsl_glslls_executable'),
-\   'command_callback': 'ale_linters#glsl#glslls#GetCommand',
-\   'project_root_callback': 'ale_linters#glsl#glslls#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'glsl_glslls_executable')},
+\   'command': function('ale_linters#glsl#glslls#GetCommand'),
+\   'project_root': function('ale_linters#glsl#glslls#GetProjectRoot'),
 \})
diff --git a/ale_linters/go/bingo.vim b/ale_linters/go/bingo.vim
index ba80fbe8..e446bdcc 100644
--- a/ale_linters/go/bingo.vim
+++ b/ale_linters/go/bingo.vim
@@ -23,7 +23,7 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'bingo',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('go_bingo_executable'),
-\   'command_callback': 'ale_linters#go#bingo#GetCommand',
-\   'project_root_callback': 'ale_linters#go#bingo#FindProjectRoot',
+\   'executable': {b -> ale#Var(b, 'go_bingo_executable')},
+\   'command': function('ale_linters#go#bingo#GetCommand'),
+\   'project_root': function('ale_linters#go#bingo#FindProjectRoot'),
 \})
diff --git a/ale_linters/go/gobuild.vim b/ale_linters/go/gobuild.vim
index cef1ff88..374ded35 100644
--- a/ale_linters/go/gobuild.vim
+++ b/ale_linters/go/gobuild.vim
@@ -48,8 +48,8 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'gobuild',
 \   'aliases': ['go build'],
-\   'executable_callback': ale#VarFunc('go_go_executable'),
-\   'command_callback': 'ale_linters#go#gobuild#GetCommand',
+\   'executable': {b -> ale#Var(b, 'go_go_executable')},
+\   'command': function('ale_linters#go#gobuild#GetCommand'),
 \   'output_stream': 'stderr',
 \   'callback': 'ale_linters#go#gobuild#Handler',
 \   'lint_file': 1,
diff --git a/ale_linters/go/golangci_lint.vim b/ale_linters/go/golangci_lint.vim
index dd9a3c64..357f7949 100644
--- a/ale_linters/go/golangci_lint.vim
+++ b/ale_linters/go/golangci_lint.vim
@@ -49,8 +49,8 @@ endfunction
 
 call ale#linter#Define('go', {
 \   'name': 'golangci-lint',
-\   'executable_callback': ale#VarFunc('go_golangci_lint_executable'),
-\   'command_callback': 'ale_linters#go#golangci_lint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'go_golangci_lint_executable')},
+\   'command': function('ale_linters#go#golangci_lint#GetCommand'),
 \   'callback': 'ale_linters#go#golangci_lint#Handler',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/go/golint.vim b/ale_linters/go/golint.vim
index 4bf14fcc..765e1477 100644
--- a/ale_linters/go/golint.vim
+++ b/ale_linters/go/golint.vim
@@ -15,7 +15,7 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'golint',
 \   'output_stream': 'both',
-\   'executable_callback': ale#VarFunc('go_golint_executable'),
-\   'command_callback': 'ale_linters#go#golint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'go_golint_executable')},
+\   'command': function('ale_linters#go#golint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsWarning',
 \})
diff --git a/ale_linters/go/gometalinter.vim b/ale_linters/go/gometalinter.vim
index d005e1d2..19d70a81 100644
--- a/ale_linters/go/gometalinter.vim
+++ b/ale_linters/go/gometalinter.vim
@@ -50,8 +50,8 @@ endfunction
 
 call ale#linter#Define('go', {
 \   'name': 'gometalinter',
-\   'executable_callback': ale#VarFunc('go_gometalinter_executable'),
-\   'command_callback': 'ale_linters#go#gometalinter#GetCommand',
+\   'executable': {b -> ale#Var(b, 'go_gometalinter_executable')},
+\   'command': function('ale_linters#go#gometalinter#GetCommand'),
 \   'callback': 'ale_linters#go#gometalinter#Handler',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/go/gosimple.vim b/ale_linters/go/gosimple.vim
index dbdc3fcf..281a0e53 100644
--- a/ale_linters/go/gosimple.vim
+++ b/ale_linters/go/gosimple.vim
@@ -8,7 +8,7 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'gosimple',
 \   'executable': 'gosimple',
-\   'command_callback': 'ale_linters#go#gosimple#GetCommand',
+\   'command': function('ale_linters#go#gosimple#GetCommand'),
 \   'callback': 'ale#handlers#go#Handler',
 \   'output_stream': 'both',
 \   'lint_file': 1,
diff --git a/ale_linters/go/gotype.vim b/ale_linters/go/gotype.vim
index a678e0f3..159df892 100644
--- a/ale_linters/go/gotype.vim
+++ b/ale_linters/go/gotype.vim
@@ -13,7 +13,7 @@ call ale#linter#Define('go', {
 \   'name': 'gotype',
 \   'output_stream': 'stderr',
 \   'executable': 'gotype',
-\   'command_callback': 'ale_linters#go#gotype#GetCommand',
+\   'command': function('ale_linters#go#gotype#GetCommand'),
 \   'callback': 'ale#handlers#go#Handler',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/go/govet.vim b/ale_linters/go/govet.vim
index 3d0d2adf..bb81d5d0 100644
--- a/ale_linters/go/govet.vim
+++ b/ale_linters/go/govet.vim
@@ -20,8 +20,8 @@ call ale#linter#Define('go', {
 \   'name': 'govet',
 \   'aliases': ['go vet'],
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('go_go_executable'),
-\   'command_callback': 'ale_linters#go#govet#GetCommand',
+\   'executable': {b -> ale#Var(b, 'go_go_executable')},
+\   'command': function('ale_linters#go#govet#GetCommand'),
 \   'callback': 'ale#handlers#go#Handler',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/go/langserver.vim b/ale_linters/go/langserver.vim
index e049be7b..776186c7 100644
--- a/ale_linters/go/langserver.vim
+++ b/ale_linters/go/langserver.vim
@@ -22,7 +22,7 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'golangserver',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('go_langserver_executable'),
-\   'command_callback': 'ale_linters#go#langserver#GetCommand',
-\   'project_root_callback': 'ale#go#FindProjectRoot',
+\   'executable': {b -> ale#Var(b, 'go_langserver_executable')},
+\   'command': function('ale_linters#go#langserver#GetCommand'),
+\   'project_root': function('ale#go#FindProjectRoot'),
 \})
diff --git a/ale_linters/go/staticcheck.vim b/ale_linters/go/staticcheck.vim
index a3464015..26fe0193 100644
--- a/ale_linters/go/staticcheck.vim
+++ b/ale_linters/go/staticcheck.vim
@@ -26,7 +26,7 @@ endfunction
 call ale#linter#Define('go', {
 \   'name': 'staticcheck',
 \   'executable': 'staticcheck',
-\   'command_callback': 'ale_linters#go#staticcheck#GetCommand',
+\   'command': function('ale_linters#go#staticcheck#GetCommand'),
 \   'callback': 'ale#handlers#go#Handler',
 \   'output_stream': 'both',
 \   'lint_file': 1,
diff --git a/ale_linters/graphql/eslint.vim b/ale_linters/graphql/eslint.vim
index dfcbf9d9..654b8c17 100644
--- a/ale_linters/graphql/eslint.vim
+++ b/ale_linters/graphql/eslint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('graphql', {
 \   'name': 'eslint',
-\   'executable_callback': 'ale#handlers#eslint#GetExecutable',
-\   'command_callback': 'ale#handlers#eslint#GetCommand',
+\   'executable': function('ale#handlers#eslint#GetExecutable'),
+\   'command': function('ale#handlers#eslint#GetCommand'),
 \   'callback': 'ale#handlers#eslint#Handle',
 \})
diff --git a/ale_linters/graphql/gqlint.vim b/ale_linters/graphql/gqlint.vim
index e45bf4c8..d5029de1 100644
--- a/ale_linters/graphql/gqlint.vim
+++ b/ale_linters/graphql/gqlint.vim
@@ -10,6 +10,6 @@ endfunction
 call ale#linter#Define('graphql', {
 \   'name': 'gqlint',
 \   'executable': 'gqlint',
-\   'command_callback': 'ale_linters#graphql#gqlint#GetCommand',
+\   'command': function('ale_linters#graphql#gqlint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsWarning',
 \})
diff --git a/ale_linters/hack/hack.vim b/ale_linters/hack/hack.vim
index aea428cc..822b5c87 100644
--- a/ale_linters/hack/hack.vim
+++ b/ale_linters/hack/hack.vim
@@ -16,7 +16,7 @@ endfunction
 call ale#linter#Define('hack', {
 \   'name': 'hack',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#hack#hack#GetExecutable',
+\   'executable': function('ale_linters#hack#hack#GetExecutable'),
 \   'command': '%e lsp --from vim-ale',
-\   'project_root_callback': 'ale_linters#hack#hack#GetProjectRoot',
+\   'project_root': function('ale_linters#hack#hack#GetProjectRoot'),
 \})
diff --git a/ale_linters/hack/hhast.vim b/ale_linters/hack/hhast.vim
index f6870b59..5e6d4dec 100644
--- a/ale_linters/hack/hhast.vim
+++ b/ale_linters/hack/hhast.vim
@@ -33,8 +33,8 @@ endfunction
 call ale#linter#Define('hack', {
 \   'name': 'hhast',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#hack#hhast#GetExecutable',
+\   'executable': function('ale_linters#hack#hhast#GetExecutable'),
 \   'command': '%e --mode lsp --from vim-ale',
-\   'project_root_callback': 'ale_linters#hack#hhast#GetProjectRoot',
-\   'initialization_options_callback': 'ale_linters#hack#hhast#GetInitializationOptions',
+\   'project_root': function('ale_linters#hack#hhast#GetProjectRoot'),
+\   'initialization_options': function('ale_linters#hack#hhast#GetInitializationOptions'),
 \})
diff --git a/ale_linters/haml/hamllint.vim b/ale_linters/haml/hamllint.vim
index 6598f81a..7d7278aa 100644
--- a/ale_linters/haml/hamllint.vim
+++ b/ale_linters/haml/hamllint.vim
@@ -51,7 +51,7 @@ endfunction
 
 call ale#linter#Define('haml', {
 \   'name': 'hamllint',
-\   'executable_callback': 'ale_linters#haml#hamllint#GetExecutable',
-\   'command_callback': 'ale_linters#haml#hamllint#GetCommand',
+\   'executable': function('ale_linters#haml#hamllint#GetExecutable'),
+\   'command': function('ale_linters#haml#hamllint#GetCommand'),
 \   'callback': 'ale_linters#haml#hamllint#Handle'
 \})
diff --git a/ale_linters/handlebars/embertemplatelint.vim b/ale_linters/handlebars/embertemplatelint.vim
index 4fc0f20d..74bd6a99 100644
--- a/ale_linters/handlebars/embertemplatelint.vim
+++ b/ale_linters/handlebars/embertemplatelint.vim
@@ -31,9 +31,9 @@ endfunction
 
 call ale#linter#Define('handlebars', {
 \   'name': 'ember-template-lint',
-\   'executable_callback': ale#node#FindExecutableFunc('handlebars_embertemplatelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'handlebars_embertemplatelint', [
 \       'node_modules/.bin/ember-template-lint',
-\   ]),
+\   ])},
 \   'command': '%e --json %t',
 \   'callback': 'ale_linters#handlebars#embertemplatelint#Handle',
 \})
diff --git a/ale_linters/haskell/cabal_ghc.vim b/ale_linters/haskell/cabal_ghc.vim
index 003adf5d..59978e7e 100644
--- a/ale_linters/haskell/cabal_ghc.vim
+++ b/ale_linters/haskell/cabal_ghc.vim
@@ -14,6 +14,6 @@ call ale#linter#Define('haskell', {
 \   'aliases': ['cabal-ghc'],
 \   'output_stream': 'stderr',
 \   'executable': 'cabal',
-\   'command_callback': 'ale_linters#haskell#cabal_ghc#GetCommand',
+\   'command': function('ale_linters#haskell#cabal_ghc#GetCommand'),
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/haskell/ghc.vim b/ale_linters/haskell/ghc.vim
index daf91c8f..9c3906b2 100644
--- a/ale_linters/haskell/ghc.vim
+++ b/ale_linters/haskell/ghc.vim
@@ -13,6 +13,6 @@ call ale#linter#Define('haskell', {
 \   'name': 'ghc',
 \   'output_stream': 'stderr',
 \   'executable': 'ghc',
-\   'command_callback': 'ale_linters#haskell#ghc#GetCommand',
+\   'command': function('ale_linters#haskell#ghc#GetCommand'),
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/haskell/ghc_mod.vim b/ale_linters/haskell/ghc_mod.vim
index 9762be7a..30e96b40 100644
--- a/ale_linters/haskell/ghc_mod.vim
+++ b/ale_linters/haskell/ghc_mod.vim
@@ -13,7 +13,7 @@ endfunction
 call ale#linter#Define('haskell', {
 \   'name': 'ghc_mod',
 \   'aliases': ['ghc-mod'],
-\   'executable_callback': ale#VarFunc('haskell_ghc_mod_executable'),
-\   'command_callback': 'ale_linters#haskell#ghc_mod#GetCommand',
+\   'executable': {b -> ale#Var(b, 'haskell_ghc_mod_executable')},
+\   'command': function('ale_linters#haskell#ghc_mod#GetCommand'),
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/haskell/hdevtools.vim b/ale_linters/haskell/hdevtools.vim
index cc5ce56f..3e55e4f0 100644
--- a/ale_linters/haskell/hdevtools.vim
+++ b/ale_linters/haskell/hdevtools.vim
@@ -14,7 +14,7 @@ endfunction
 
 call ale#linter#Define('haskell', {
 \   'name': 'hdevtools',
-\   'executable_callback': ale#VarFunc('haskell_hdevtools_executable'),
-\   'command_callback': 'ale_linters#haskell#hdevtools#GetCommand',
+\   'executable': {b -> ale#Var(b, 'haskell_hdevtools_executable')},
+\   'command': function('ale_linters#haskell#hdevtools#GetCommand'),
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/haskell/hie.vim b/ale_linters/haskell/hie.vim
index cc85fbed..c4b5f1df 100644
--- a/ale_linters/haskell/hie.vim
+++ b/ale_linters/haskell/hie.vim
@@ -35,7 +35,7 @@ endfunction
 call ale#linter#Define('haskell', {
 \   'name': 'hie',
 \   'lsp': 'stdio',
-\   'command_callback': 'ale_linters#haskell#hie#GetCommand',
-\   'executable_callback': ale#VarFunc('haskell_hie_executable'),
-\   'project_root_callback': 'ale_linters#haskell#hie#GetProjectRoot',
+\   'command': function('ale_linters#haskell#hie#GetCommand'),
+\   'executable': {b -> ale#Var(b, 'haskell_hie_executable')},
+\   'project_root': function('ale_linters#haskell#hie#GetProjectRoot'),
 \})
diff --git a/ale_linters/haskell/hlint.vim b/ale_linters/haskell/hlint.vim
index 0cc7437f..1425251a 100644
--- a/ale_linters/haskell/hlint.vim
+++ b/ale_linters/haskell/hlint.vim
@@ -40,7 +40,7 @@ endfunction
 
 call ale#linter#Define('haskell', {
 \   'name': 'hlint',
-\   'executable_callback': ale#VarFunc('haskell_hlint_executable'),
-\   'command_callback': 'ale_linters#haskell#hlint#GetCommand' ,
+\   'executable': {b -> ale#Var(b, 'haskell_hlint_executable')},
+\   'command': function('ale_linters#haskell#hlint#GetCommand') ,
 \   'callback': 'ale_linters#haskell#hlint#Handle',
 \})
diff --git a/ale_linters/haskell/stack_build.vim b/ale_linters/haskell/stack_build.vim
index 95a54587..8f2d9fd9 100644
--- a/ale_linters/haskell/stack_build.vim
+++ b/ale_linters/haskell/stack_build.vim
@@ -16,8 +16,8 @@ call ale#linter#Define('haskell', {
 \   'name': 'stack_build',
 \   'aliases': ['stack-build'],
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale#handlers#haskell#GetStackExecutable',
-\   'command_callback': 'ale_linters#haskell#stack_build#GetCommand',
+\   'executable': function('ale#handlers#haskell#GetStackExecutable'),
+\   'command': function('ale_linters#haskell#stack_build#GetCommand'),
 \   'lint_file': 1,
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/haskell/stack_ghc.vim b/ale_linters/haskell/stack_ghc.vim
index 99aa2540..06af7f6d 100644
--- a/ale_linters/haskell/stack_ghc.vim
+++ b/ale_linters/haskell/stack_ghc.vim
@@ -14,7 +14,7 @@ call ale#linter#Define('haskell', {
 \   'name': 'stack_ghc',
 \   'aliases': ['stack-ghc'],
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale#handlers#haskell#GetStackExecutable',
-\   'command_callback': 'ale_linters#haskell#stack_ghc#GetCommand',
+\   'executable': function('ale#handlers#haskell#GetStackExecutable'),
+\   'command': function('ale_linters#haskell#stack_ghc#GetCommand'),
 \   'callback': 'ale#handlers#haskell#HandleGHCFormat',
 \})
diff --git a/ale_linters/html/htmlhint.vim b/ale_linters/html/htmlhint.vim
index 234c1176..3e01f51a 100644
--- a/ale_linters/html/htmlhint.vim
+++ b/ale_linters/html/htmlhint.vim
@@ -24,9 +24,9 @@ endfunction
 
 call ale#linter#Define('html', {
 \   'name': 'htmlhint',
-\   'executable_callback': ale#node#FindExecutableFunc('html_htmlhint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'html_htmlhint', [
 \       'node_modules/.bin/htmlhint',
-\   ]),
-\   'command_callback': 'ale_linters#html#htmlhint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#html#htmlhint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsError',
 \})
diff --git a/ale_linters/html/stylelint.vim b/ale_linters/html/stylelint.vim
index 908c4b02..ae8955f3 100644
--- a/ale_linters/html/stylelint.vim
+++ b/ale_linters/html/stylelint.vim
@@ -21,7 +21,7 @@ endfunction
 
 call ale#linter#Define('html', {
 \   'name': 'stylelint',
-\   'executable_callback': 'ale_linters#html#stylelint#GetExecutable',
-\   'command_callback': 'ale_linters#html#stylelint#GetCommand',
+\   'executable': function('ale_linters#html#stylelint#GetExecutable'),
+\   'command': function('ale_linters#html#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/html/tidy.vim b/ale_linters/html/tidy.vim
index 4ec29091..1e476d40 100644
--- a/ale_linters/html/tidy.vim
+++ b/ale_linters/html/tidy.vim
@@ -63,8 +63,8 @@ endfunction
 
 call ale#linter#Define('html', {
 \   'name': 'tidy',
-\   'executable_callback': ale#VarFunc('html_tidy_executable'),
+\   'executable': {b -> ale#Var(b, 'html_tidy_executable')},
 \   'output_stream': 'stderr',
-\   'command_callback': 'ale_linters#html#tidy#GetCommand',
+\   'command': function('ale_linters#html#tidy#GetCommand'),
 \   'callback': 'ale_linters#html#tidy#Handle',
 \ })
diff --git a/ale_linters/idris/idris.vim b/ale_linters/idris/idris.vim
index 42b88158..879e92f2 100644
--- a/ale_linters/idris/idris.vim
+++ b/ale_linters/idris/idris.vim
@@ -75,7 +75,7 @@ endfunction
 
 call ale#linter#Define('idris', {
 \   'name': 'idris',
-\   'executable_callback': ale#VarFunc('idris_idris_executable'),
-\   'command_callback': 'ale_linters#idris#idris#GetCommand',
+\   'executable': {b -> ale#Var(b, 'idris_idris_executable')},
+\   'command': function('ale_linters#idris#idris#GetCommand'),
 \   'callback': 'ale_linters#idris#idris#Handle',
 \})
diff --git a/ale_linters/ispc/ispc.vim b/ale_linters/ispc/ispc.vim
index de7ceafa..eb365117 100644
--- a/ale_linters/ispc/ispc.vim
+++ b/ale_linters/ispc/ispc.vim
@@ -38,8 +38,8 @@ endfunction
 call ale#linter#Define('ispc', {
 \   'name': 'ispc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('ispc_ispc_executable'),
-\   'command_callback': 'ale_linters#ispc#ispc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'ispc_ispc_executable')},
+\   'command': function('ale_linters#ispc#ispc#GetCommand'),
 \   'callback': 'ale_linters#ispc#ispc#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/java/checkstyle.vim b/ale_linters/java/checkstyle.vim
index c07b65d0..3159cd55 100644
--- a/ale_linters/java/checkstyle.vim
+++ b/ale_linters/java/checkstyle.vim
@@ -44,7 +44,7 @@ endif
 call ale#linter#Define('java', {
 \   'name': 'checkstyle',
 \   'executable': 'checkstyle',
-\   'command_callback': 'ale_linters#java#checkstyle#GetCommand',
+\   'command': function('ale_linters#java#checkstyle#GetCommand'),
 \   'callback': 'ale_linters#java#checkstyle#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/java/javac.vim b/ale_linters/java/javac.vim
index 2aa01b4f..e903210d 100644
--- a/ale_linters/java/javac.vim
+++ b/ale_linters/java/javac.vim
@@ -120,7 +120,7 @@ endfunction
 
 call ale#linter#Define('java', {
 \   'name': 'javac',
-\   'executable_callback': ale#VarFunc('java_javac_executable'),
+\   'executable': {b -> ale#Var(b, 'java_javac_executable')},
 \   'command_chain': [
 \       {'callback': 'ale_linters#java#javac#GetImportPaths', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#java#javac#GetCommand', 'output_stream': 'stderr'},
diff --git a/ale_linters/java/javalsp.vim b/ale_linters/java/javalsp.vim
index 6329ab3c..a327363d 100644
--- a/ale_linters/java/javalsp.vim
+++ b/ale_linters/java/javalsp.vim
@@ -16,8 +16,8 @@ endfunction
 call ale#linter#Define('java', {
 \   'name': 'javalsp',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#java#javalsp#Executable',
-\   'command_callback': 'ale_linters#java#javalsp#Command',
+\   'executable': function('ale_linters#java#javalsp#Executable'),
+\   'command': function('ale_linters#java#javalsp#Command'),
 \   'language': 'java',
-\   'project_root_callback': 'ale#java#FindProjectRoot',
+\   'project_root': function('ale#java#FindProjectRoot'),
 \})
diff --git a/ale_linters/java/pmd.vim b/ale_linters/java/pmd.vim
index b530ad09..a1f4c93c 100644
--- a/ale_linters/java/pmd.vim
+++ b/ale_linters/java/pmd.vim
@@ -31,6 +31,6 @@ endif
 call ale#linter#Define('java', {
 \   'name': 'pmd',
 \   'executable': 'pmd',
-\   'command_callback': 'ale_linters#java#pmd#GetCommand',
+\   'command': function('ale_linters#java#pmd#GetCommand'),
 \   'callback': 'ale_linters#java#pmd#Handle',
 \})
diff --git a/ale_linters/javascript/eslint.vim b/ale_linters/javascript/eslint.vim
index 23e16949..8aeac2d8 100644
--- a/ale_linters/javascript/eslint.vim
+++ b/ale_linters/javascript/eslint.vim
@@ -4,7 +4,7 @@
 call ale#linter#Define('javascript', {
 \   'name': 'eslint',
 \   'output_stream': 'both',
-\   'executable_callback': 'ale#handlers#eslint#GetExecutable',
-\   'command_callback': 'ale#handlers#eslint#GetCommand',
+\   'executable': function('ale#handlers#eslint#GetExecutable'),
+\   'command': function('ale#handlers#eslint#GetCommand'),
 \   'callback': 'ale#handlers#eslint#Handle',
 \})
diff --git a/ale_linters/javascript/flow.vim b/ale_linters/javascript/flow.vim
index 0561ab74..05aae030 100755
--- a/ale_linters/javascript/flow.vim
+++ b/ale_linters/javascript/flow.vim
@@ -168,7 +168,7 @@ endfunction
 
 call ale#linter#Define('javascript', {
 \   'name': 'flow',
-\   'executable_callback': 'ale_linters#javascript#flow#GetExecutable',
+\   'executable': function('ale_linters#javascript#flow#GetExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#javascript#flow#VersionCheck'},
 \       {'callback': 'ale_linters#javascript#flow#GetCommand'},
diff --git a/ale_linters/javascript/flow_ls.vim b/ale_linters/javascript/flow_ls.vim
index 75377183..accaaa73 100644
--- a/ale_linters/javascript/flow_ls.vim
+++ b/ale_linters/javascript/flow_ls.vim
@@ -19,10 +19,10 @@ endfunction
 call ale#linter#Define('javascript', {
 \   'name': 'flow-language-server',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#node#FindExecutableFunc('javascript_flow_ls', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'javascript_flow_ls', [
 \       'node_modules/.bin/flow',
-\   ]),
+\   ])},
 \   'command': '%e lsp --from ale-lsp',
-\   'project_root_callback': 'ale_linters#javascript#flow_ls#FindProjectRoot',
+\   'project_root': function('ale_linters#javascript#flow_ls#FindProjectRoot'),
 \   'language': 'javascript',
 \})
diff --git a/ale_linters/javascript/jscs.vim b/ale_linters/javascript/jscs.vim
index a38766a6..8905b3a1 100644
--- a/ale_linters/javascript/jscs.vim
+++ b/ale_linters/javascript/jscs.vim
@@ -53,9 +53,9 @@ endfunction
 
 call ale#linter#Define('javascript', {
 \   'name': 'jscs',
-\   'executable_callback': ale#node#FindExecutableFunc('javascript_jscs', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'javascript_jscs', [
 \       'node_modules/.bin/jscs',
-\   ]),
-\   'command_callback': 'ale_linters#javascript#jscs#GetCommand',
+\   ])},
+\   'command': function('ale_linters#javascript#jscs#GetCommand'),
 \   'callback': 'ale_linters#javascript#jscs#Handle',
 \})
diff --git a/ale_linters/javascript/jshint.vim b/ale_linters/javascript/jshint.vim
index cb7f66fc..d80a2250 100644
--- a/ale_linters/javascript/jshint.vim
+++ b/ale_linters/javascript/jshint.vim
@@ -25,9 +25,9 @@ endfunction
 
 call ale#linter#Define('javascript', {
 \   'name': 'jshint',
-\   'executable_callback': ale#node#FindExecutableFunc('javascript_jshint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'javascript_jshint', [
 \       'node_modules/.bin/jshint',
-\   ]),
-\   'command_callback': 'ale_linters#javascript#jshint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#javascript#jshint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsError',
 \})
diff --git a/ale_linters/javascript/standard.vim b/ale_linters/javascript/standard.vim
index f16b837a..4cd2c303 100644
--- a/ale_linters/javascript/standard.vim
+++ b/ale_linters/javascript/standard.vim
@@ -24,7 +24,7 @@ endfunction
 " standard uses eslint and the output format is the same
 call ale#linter#Define('javascript', {
 \   'name': 'standard',
-\   'executable_callback': 'ale_linters#javascript#standard#GetExecutable',
-\   'command_callback': 'ale_linters#javascript#standard#GetCommand',
+\   'executable': function('ale_linters#javascript#standard#GetExecutable'),
+\   'command': function('ale_linters#javascript#standard#GetCommand'),
 \   'callback': 'ale#handlers#eslint#Handle',
 \})
diff --git a/ale_linters/javascript/tsserver.vim b/ale_linters/javascript/tsserver.vim
index 63509022..68c252c5 100644
--- a/ale_linters/javascript/tsserver.vim
+++ b/ale_linters/javascript/tsserver.vim
@@ -8,10 +8,10 @@ call ale#Set('javascript_tsserver_use_global', get(g:, 'ale_use_global_executabl
 call ale#linter#Define('javascript', {
 \   'name': 'tsserver',
 \   'lsp': 'tsserver',
-\   'executable_callback': ale#node#FindExecutableFunc('javascript_tsserver', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'javascript_tsserver', [
 \       'node_modules/.bin/tsserver',
-\   ]),
+\   ])},
 \   'command': '%e',
-\   'project_root_callback': 'ale#handlers#tsserver#GetProjectRoot',
+\   'project_root': function('ale#handlers#tsserver#GetProjectRoot'),
 \   'language': '',
 \})
diff --git a/ale_linters/javascript/xo.vim b/ale_linters/javascript/xo.vim
index bc8657ed..4ba39101 100644
--- a/ale_linters/javascript/xo.vim
+++ b/ale_linters/javascript/xo.vim
@@ -20,7 +20,7 @@ endfunction
 " xo uses eslint and the output format is the same
 call ale#linter#Define('javascript', {
 \   'name': 'xo',
-\   'executable_callback': 'ale_linters#javascript#xo#GetExecutable',
-\   'command_callback': 'ale_linters#javascript#xo#GetCommand',
+\   'executable': function('ale_linters#javascript#xo#GetExecutable'),
+\   'command': function('ale_linters#javascript#xo#GetCommand'),
 \   'callback': 'ale#handlers#eslint#Handle',
 \})
diff --git a/ale_linters/julia/languageserver.vim b/ale_linters/julia/languageserver.vim
index cd2000de..564bec39 100644
--- a/ale_linters/julia/languageserver.vim
+++ b/ale_linters/julia/languageserver.vim
@@ -14,8 +14,8 @@ endfunction
 call ale#linter#Define('julia', {
 \   'name': 'languageserver',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('julia_executable'),
-\   'command_callback': 'ale_linters#julia#languageserver#GetCommand',
+\   'executable': {b -> ale#Var(b, 'julia_executable')},
+\   'command': function('ale_linters#julia#languageserver#GetCommand'),
 \   'language': 'julia',
-\   'project_root_callback': 'ale#julia#FindProjectRoot',
+\   'project_root': function('ale#julia#FindProjectRoot'),
 \})
diff --git a/ale_linters/kotlin/ktlint.vim b/ale_linters/kotlin/ktlint.vim
index b8920aa7..f0384005 100644
--- a/ale_linters/kotlin/ktlint.vim
+++ b/ale_linters/kotlin/ktlint.vim
@@ -4,7 +4,7 @@
 call ale#linter#Define('kotlin', {
 \   'name': 'ktlint',
 \   'executable': 'ktlint',
-\   'command_callback': 'ale#handlers#ktlint#GetCommand',
+\   'command': function('ale#handlers#ktlint#GetCommand'),
 \   'callback': 'ale#handlers#ktlint#Handle',
 \   'lint_file': 1
 \})
diff --git a/ale_linters/kotlin/languageserver.vim b/ale_linters/kotlin/languageserver.vim
index aea817ba..af78c0e0 100644
--- a/ale_linters/kotlin/languageserver.vim
+++ b/ale_linters/kotlin/languageserver.vim
@@ -22,8 +22,8 @@ endfunction
 call ale#linter#Define('kotlin', {
 \   'name': 'languageserver',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('kotlin_languageserver_executable'),
+\   'executable': {b -> ale#Var(b, 'kotlin_languageserver_executable')},
 \   'command': '%e',
 \   'language': 'kotlin',
-\   'project_root_callback': 'ale_linters#kotlin#languageserver#GetProjectRoot',
+\   'project_root': function('ale_linters#kotlin#languageserver#GetProjectRoot'),
 \})
diff --git a/ale_linters/less/lessc.vim b/ale_linters/less/lessc.vim
index 37600649..4ec8b00e 100755
--- a/ale_linters/less/lessc.vim
+++ b/ale_linters/less/lessc.vim
@@ -38,10 +38,10 @@ endfunction
 
 call ale#linter#Define('less', {
 \   'name': 'lessc',
-\   'executable_callback': ale#node#FindExecutableFunc('less_lessc', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'less_lessc', [
 \       'node_modules/.bin/lessc',
-\   ]),
-\   'command_callback': 'ale_linters#less#lessc#GetCommand',
+\   ])},
+\   'command': function('ale_linters#less#lessc#GetCommand'),
 \   'callback': 'ale_linters#less#lessc#Handle',
 \   'output_stream': 'stderr',
 \})
diff --git a/ale_linters/less/stylelint.vim b/ale_linters/less/stylelint.vim
index 479808c2..efb036c2 100644
--- a/ale_linters/less/stylelint.vim
+++ b/ale_linters/less/stylelint.vim
@@ -12,9 +12,9 @@ endfunction
 
 call ale#linter#Define('less', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('less_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'less_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
-\   'command_callback': 'ale_linters#less#stylelint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#less#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/llvm/llc.vim b/ale_linters/llvm/llc.vim
index 044f8c44..594be063 100644
--- a/ale_linters/llvm/llc.vim
+++ b/ale_linters/llvm/llc.vim
@@ -17,8 +17,8 @@ endfunction
 
 call ale#linter#Define('llvm', {
 \   'name': 'llc',
-\   'executable_callback': ale#VarFunc('llvm_llc_executable'),
+\   'executable': {b -> ale#Var(b, 'llvm_llc_executable')},
 \   'output_stream': 'stderr',
-\   'command_callback': {-> '%e -filetype=null -o=' . g:ale#util#nul_file},
+\   'command': {-> '%e -filetype=null -o=' . g:ale#util#nul_file},
 \   'callback': 'ale_linters#llvm#llc#HandleErrors',
 \})
diff --git a/ale_linters/lua/luac.vim b/ale_linters/lua/luac.vim
index bca2cd8d..41674a43 100644
--- a/ale_linters/lua/luac.vim
+++ b/ale_linters/lua/luac.vim
@@ -24,7 +24,7 @@ endfunction
 
 call ale#linter#Define('lua', {
 \   'name': 'luac',
-\   'executable_callback': ale#VarFunc('lua_luac_executable'),
+\   'executable': {b -> ale#Var(b, 'lua_luac_executable')},
 \   'command': '%e -p -',
 \   'output_stream': 'stderr',
 \   'callback': 'ale_linters#lua#luac#Handle',
diff --git a/ale_linters/lua/luacheck.vim b/ale_linters/lua/luacheck.vim
index 669103b8..34be2b5a 100644
--- a/ale_linters/lua/luacheck.vim
+++ b/ale_linters/lua/luacheck.vim
@@ -38,7 +38,7 @@ endfunction
 
 call ale#linter#Define('lua', {
 \   'name': 'luacheck',
-\   'executable_callback': ale#VarFunc('lua_luacheck_executable'),
-\   'command_callback': 'ale_linters#lua#luacheck#GetCommand',
+\   'executable': {b -> ale#Var(b, 'lua_luacheck_executable')},
+\   'command': function('ale_linters#lua#luacheck#GetCommand'),
 \   'callback': 'ale_linters#lua#luacheck#Handle',
 \})
diff --git a/ale_linters/markdown/mdl.vim b/ale_linters/markdown/mdl.vim
index 0953144b..305f5359 100644
--- a/ale_linters/markdown/mdl.vim
+++ b/ale_linters/markdown/mdl.vim
@@ -38,7 +38,7 @@ endfunction
 
 call ale#linter#Define('markdown', {
 \   'name': 'mdl',
-\   'executable_callback': 'ale_linters#markdown#mdl#GetExecutable',
-\   'command_callback': 'ale_linters#markdown#mdl#GetCommand',
+\   'executable': function('ale_linters#markdown#mdl#GetExecutable'),
+\   'command': function('ale_linters#markdown#mdl#GetCommand'),
 \   'callback': 'ale_linters#markdown#mdl#Handle'
 \})
diff --git a/ale_linters/markdown/remark_lint.vim b/ale_linters/markdown/remark_lint.vim
index 4f8d48fa..ed87d1ad 100644
--- a/ale_linters/markdown/remark_lint.vim
+++ b/ale_linters/markdown/remark_lint.vim
@@ -39,10 +39,10 @@ endfunction
 call ale#linter#Define('markdown', {
 \   'name': 'remark_lint',
 \   'aliases': ['remark-lint'],
-\   'executable_callback': ale#node#FindExecutableFunc('markdown_remark_lint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'markdown_remark_lint', [
 \       'node_modules/.bin/remark',
-\   ]),
-\   'command_callback': 'ale_linters#markdown#remark_lint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#markdown#remark_lint#GetCommand'),
 \   'callback': 'ale_linters#markdown#remark_lint#Handle',
 \   'output_stream': 'stderr',
 \})
diff --git a/ale_linters/markdown/textlint.vim b/ale_linters/markdown/textlint.vim
index 26458506..613c8411 100644
--- a/ale_linters/markdown/textlint.vim
+++ b/ale_linters/markdown/textlint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('markdown', {
 \   'name': 'textlint',
-\   'executable_callback': 'ale#handlers#textlint#GetExecutable',
-\   'command_callback': 'ale#handlers#textlint#GetCommand',
+\   'executable': function('ale#handlers#textlint#GetExecutable'),
+\   'command': function('ale#handlers#textlint#GetCommand'),
 \   'callback': 'ale#handlers#textlint#HandleTextlintOutput',
 \})
diff --git a/ale_linters/matlab/mlint.vim b/ale_linters/matlab/mlint.vim
index 3435045e..f58f8b6d 100644
--- a/ale_linters/matlab/mlint.vim
+++ b/ale_linters/matlab/mlint.vim
@@ -37,7 +37,7 @@ endfunction
 
 call ale#linter#Define('matlab', {
 \   'name': 'mlint',
-\   'executable_callback': ale#VarFunc('matlab_mlint_executable'),
+\   'executable': {b -> ale#Var(b, 'matlab_mlint_executable')},
 \   'command': '%e -id %t',
 \   'output_stream': 'stderr',
 \   'callback': 'ale_linters#matlab#mlint#Handle',
diff --git a/ale_linters/mercury/mmc.vim b/ale_linters/mercury/mmc.vim
index 76d357f0..8a9ccc0e 100644
--- a/ale_linters/mercury/mmc.vim
+++ b/ale_linters/mercury/mmc.vim
@@ -33,8 +33,8 @@ endfunction
 call ale#linter#Define('mercury', {
 \   'name': 'mmc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('mercury_mmc_executable'),
-\   'command_callback': 'ale_linters#mercury#mmc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'mercury_mmc_executable')},
+\   'command': function('ale_linters#mercury#mmc#GetCommand'),
 \   'callback': 'ale_linters#mercury#mmc#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/nasm/nasm.vim b/ale_linters/nasm/nasm.vim
index cb2119a6..347abc1b 100644
--- a/ale_linters/nasm/nasm.vim
+++ b/ale_linters/nasm/nasm.vim
@@ -36,7 +36,7 @@ call ale#linter#Define('nasm', {
 \   'name': 'nasm',
 \   'output_stream': 'stderr',
 \   'lint_file': 1,
-\   'executable_callback': ale#VarFunc('nasm_nasm_executable'),
-\   'command_callback': 'ale_linters#nasm#nasm#GetCommand',
+\   'executable': {b -> ale#Var(b, 'nasm_nasm_executable')},
+\   'command': function('ale_linters#nasm#nasm#GetCommand'),
 \   'callback': 'ale_linters#nasm#nasm#Handle',
 \})
diff --git a/ale_linters/nim/nimcheck.vim b/ale_linters/nim/nimcheck.vim
index bff45f7d..b5796dcd 100644
--- a/ale_linters/nim/nimcheck.vim
+++ b/ale_linters/nim/nimcheck.vim
@@ -59,7 +59,7 @@ call ale#linter#Define('nim', {
 \    'name': 'nimcheck',
 \    'executable': 'nim',
 \    'output_stream': 'both',
-\    'command_callback': 'ale_linters#nim#nimcheck#GetCommand',
+\    'command': function('ale_linters#nim#nimcheck#GetCommand'),
 \    'callback': 'ale_linters#nim#nimcheck#Handle',
 \    'lint_file': 1,
 \})
diff --git a/ale_linters/objc/ccls.vim b/ale_linters/objc/ccls.vim
index 0aa6a5e5..51ecf056 100644
--- a/ale_linters/objc/ccls.vim
+++ b/ale_linters/objc/ccls.vim
@@ -7,8 +7,8 @@ call ale#Set('objc_ccls_init_options', {})
 call ale#linter#Define('objc', {
 \   'name': 'ccls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('objc_ccls_executable'),
+\   'executable': {b -> ale#Var(b, 'objc_ccls_executable')},
 \   'command': '%e',
-\   'project_root_callback': 'ale#handlers#ccls#GetProjectRoot',
-\   'initialization_options_callback': ale#VarFunc('objc_ccls_init_options'),
+\   'project_root': function('ale#handlers#ccls#GetProjectRoot'),
+\   'initialization_options': {b -> ale#Var(b, 'objc_ccls_init_options')},
 \})
diff --git a/ale_linters/objc/clang.vim b/ale_linters/objc/clang.vim
index 4e80ac5c..7873dccd 100644
--- a/ale_linters/objc/clang.vim
+++ b/ale_linters/objc/clang.vim
@@ -18,6 +18,6 @@ call ale#linter#Define('objc', {
 \   'name': 'clang',
 \   'output_stream': 'stderr',
 \   'executable': 'clang',
-\   'command_callback': 'ale_linters#objc#clang#GetCommand',
+\   'command': function('ale_linters#objc#clang#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormatWithIncludes',
 \})
diff --git a/ale_linters/objc/clangd.vim b/ale_linters/objc/clangd.vim
index f090e6ce..ab52fec3 100644
--- a/ale_linters/objc/clangd.vim
+++ b/ale_linters/objc/clangd.vim
@@ -17,7 +17,7 @@ endfunction
 call ale#linter#Define('objc', {
 \   'name': 'clangd',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('objc_clangd_executable'),
-\   'command_callback': 'ale_linters#objc#clangd#GetCommand',
-\   'project_root_callback': 'ale_linters#objc#clangd#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'objc_clangd_executable')},
+\   'command': function('ale_linters#objc#clangd#GetCommand'),
+\   'project_root': function('ale_linters#objc#clangd#GetProjectRoot'),
 \})
diff --git a/ale_linters/objcpp/clang.vim b/ale_linters/objcpp/clang.vim
index d1474f17..4dbe55b3 100644
--- a/ale_linters/objcpp/clang.vim
+++ b/ale_linters/objcpp/clang.vim
@@ -18,6 +18,6 @@ call ale#linter#Define('objcpp', {
 \   'name': 'clang',
 \   'output_stream': 'stderr',
 \   'executable': 'clang++',
-\   'command_callback': 'ale_linters#objcpp#clang#GetCommand',
+\   'command': function('ale_linters#objcpp#clang#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormatWithIncludes',
 \})
diff --git a/ale_linters/objcpp/clangd.vim b/ale_linters/objcpp/clangd.vim
index a09753be..3991d2ac 100644
--- a/ale_linters/objcpp/clangd.vim
+++ b/ale_linters/objcpp/clangd.vim
@@ -17,7 +17,7 @@ endfunction
 call ale#linter#Define('objcpp', {
 \   'name': 'clangd',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('objcpp_clangd_executable'),
-\   'command_callback': 'ale_linters#objcpp#clangd#GetCommand',
-\   'project_root_callback': 'ale_linters#objcpp#clangd#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'objcpp_clangd_executable')},
+\   'command': function('ale_linters#objcpp#clangd#GetCommand'),
+\   'project_root': function('ale_linters#objcpp#clangd#GetProjectRoot'),
 \})
diff --git a/ale_linters/ocaml/ols.vim b/ale_linters/ocaml/ols.vim
index 077862fc..d8208c52 100644
--- a/ale_linters/ocaml/ols.vim
+++ b/ale_linters/ocaml/ols.vim
@@ -7,8 +7,8 @@ call ale#Set('ocaml_ols_use_global', get(g:, 'ale_use_global_executables', 0))
 call ale#linter#Define('ocaml', {
 \   'name': 'ols',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale#handlers#ols#GetExecutable',
-\   'command_callback': 'ale#handlers#ols#GetCommand',
+\   'executable': function('ale#handlers#ols#GetExecutable'),
+\   'command': function('ale#handlers#ols#GetCommand'),
 \   'language_callback': 'ale#handlers#ols#GetLanguage',
-\   'project_root_callback': 'ale#handlers#ols#GetProjectRoot',
+\   'project_root': function('ale#handlers#ols#GetProjectRoot'),
 \})
diff --git a/ale_linters/perl/perl.vim b/ale_linters/perl/perl.vim
index 4b954f0d..0f06528a 100644
--- a/ale_linters/perl/perl.vim
+++ b/ale_linters/perl/perl.vim
@@ -57,8 +57,8 @@ endfunction
 
 call ale#linter#Define('perl', {
 \   'name': 'perl',
-\   'executable_callback': ale#VarFunc('perl_perl_executable'),
+\   'executable': {b -> ale#Var(b, 'perl_perl_executable')},
 \   'output_stream': 'both',
-\   'command_callback': 'ale_linters#perl#perl#GetCommand',
+\   'command': function('ale_linters#perl#perl#GetCommand'),
 \   'callback': 'ale_linters#perl#perl#Handle',
 \})
diff --git a/ale_linters/perl/perlcritic.vim b/ale_linters/perl/perlcritic.vim
index 8619a404..f3154c09 100644
--- a/ale_linters/perl/perlcritic.vim
+++ b/ale_linters/perl/perlcritic.vim
@@ -55,7 +55,7 @@ endfunction
 call ale#linter#Define('perl', {
 \   'name': 'perlcritic',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('perl_perlcritic_executable'),
-\   'command_callback': 'ale_linters#perl#perlcritic#GetCommand',
+\   'executable': {b -> ale#Var(b, 'perl_perlcritic_executable')},
+\   'command': function('ale_linters#perl#perlcritic#GetCommand'),
 \   'callback': 'ale_linters#perl#perlcritic#Handle',
 \})
diff --git a/ale_linters/perl6/perl6.vim b/ale_linters/perl6/perl6.vim
index 39406ac4..68ef4769 100644
--- a/ale_linters/perl6/perl6.vim
+++ b/ale_linters/perl6/perl6.vim
@@ -158,9 +158,9 @@ endfunction
 
 call ale#linter#Define('perl6', {
 \   'name': 'perl6',
-\   'executable_callback': 'ale_linters#perl6#perl6#GetExecutable',
+\   'executable': function('ale_linters#perl6#perl6#GetExecutable'),
 \   'output_stream': 'both',
-\   'command_callback': 'ale_linters#perl6#perl6#GetCommand',
+\   'command': function('ale_linters#perl6#perl6#GetCommand'),
 \   'callback': 'ale_linters#perl6#perl6#Handle',
 \})
 
diff --git a/ale_linters/php/langserver.vim b/ale_linters/php/langserver.vim
index ca91db4c..c88281c4 100644
--- a/ale_linters/php/langserver.vim
+++ b/ale_linters/php/langserver.vim
@@ -13,9 +13,9 @@ endfunction
 call ale#linter#Define('php', {
 \   'name': 'langserver',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#node#FindExecutableFunc('php_langserver', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'php_langserver', [
 \       'vendor/bin/php-language-server.php',
-\   ]),
+\   ])},
 \   'command': 'php %e',
-\   'project_root_callback': 'ale_linters#php#langserver#GetProjectRoot',
+\   'project_root': function('ale_linters#php#langserver#GetProjectRoot'),
 \})
diff --git a/ale_linters/php/phan.vim b/ale_linters/php/phan.vim
index c6f16356..53cb1ea9 100644
--- a/ale_linters/php/phan.vim
+++ b/ale_linters/php/phan.vim
@@ -67,7 +67,7 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'phan',
-\   'executable_callback': 'ale_linters#php#phan#GetExecutable',
-\   'command_callback': 'ale_linters#php#phan#GetCommand',
+\   'executable': function('ale_linters#php#phan#GetExecutable'),
+\   'command': function('ale_linters#php#phan#GetCommand'),
 \   'callback': 'ale_linters#php#phan#Handle',
 \})
diff --git a/ale_linters/php/php.vim b/ale_linters/php/php.vim
index 5d87196c..51a109b9 100644
--- a/ale_linters/php/php.vim
+++ b/ale_linters/php/php.vim
@@ -32,7 +32,7 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'php',
-\   'executable_callback': ale#VarFunc('php_php_executable'),
+\   'executable': {b -> ale#Var(b, 'php_php_executable')},
 \   'output_stream': 'stdout',
 \   'command': '%e -l -d error_reporting=E_ALL -d display_errors=1 -d log_errors=0 --',
 \   'callback': 'ale_linters#php#php#Handle',
diff --git a/ale_linters/php/phpcs.vim b/ale_linters/php/phpcs.vim
index 408c2652..1c92bbb2 100644
--- a/ale_linters/php/phpcs.vim
+++ b/ale_linters/php/phpcs.vim
@@ -44,10 +44,10 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'phpcs',
-\   'executable_callback': ale#node#FindExecutableFunc('php_phpcs', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'php_phpcs', [
 \       'vendor/bin/phpcs',
 \       'phpcs'
-\   ]),
-\   'command_callback': 'ale_linters#php#phpcs#GetCommand',
+\   ])},
+\   'command': function('ale_linters#php#phpcs#GetCommand'),
 \   'callback': 'ale_linters#php#phpcs#Handle',
 \})
diff --git a/ale_linters/php/phpmd.vim b/ale_linters/php/phpmd.vim
index 65f1cc3c..9b1d1e44 100644
--- a/ale_linters/php/phpmd.vim
+++ b/ale_linters/php/phpmd.vim
@@ -32,7 +32,7 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'phpmd',
-\   'executable_callback': ale#VarFunc('php_phpmd_executable'),
-\   'command_callback': 'ale_linters#php#phpmd#GetCommand',
+\   'executable': {b -> ale#Var(b, 'php_phpmd_executable')},
+\   'command': function('ale_linters#php#phpmd#GetCommand'),
 \   'callback': 'ale_linters#php#phpmd#Handle',
 \})
diff --git a/ale_linters/php/phpstan.vim b/ale_linters/php/phpstan.vim
index 1c831e1b..34d4e799 100644
--- a/ale_linters/php/phpstan.vim
+++ b/ale_linters/php/phpstan.vim
@@ -65,7 +65,7 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'phpstan',
-\   'executable_callback': 'ale_linters#php#phpstan#GetExecutable',
+\   'executable': function('ale_linters#php#phpstan#GetExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#php#phpstan#VersionCheck'},
 \       {'callback': 'ale_linters#php#phpstan#GetCommand'},
diff --git a/ale_linters/php/psalm.vim b/ale_linters/php/psalm.vim
index dce59178..3cdb026a 100644
--- a/ale_linters/php/psalm.vim
+++ b/ale_linters/php/psalm.vim
@@ -13,9 +13,9 @@ endfunction
 call ale#linter#Define('php', {
 \   'name': 'psalm',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#node#FindExecutableFunc('psalm_langserver', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'psalm_langserver', [
 \       'vendor/bin/psalm-language-server',
-\   ]),
+\   ])},
 \   'command': '%e',
-\   'project_root_callback': 'ale_linters#php#psalm#GetProjectRoot',
+\   'project_root': function('ale_linters#php#psalm#GetProjectRoot'),
 \})
diff --git a/ale_linters/pony/ponyc.vim b/ale_linters/pony/ponyc.vim
index 19e7e828..6d4594f9 100644
--- a/ale_linters/pony/ponyc.vim
+++ b/ale_linters/pony/ponyc.vim
@@ -10,7 +10,7 @@ endfunction
 call ale#linter#Define('pony', {
 \   'name': 'ponyc',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('pony_ponyc_executable'),
-\   'command_callback': 'ale_linters#pony#ponyc#GetCommand',
+\   'executable': {b -> ale#Var(b, 'pony_ponyc_executable')},
+\   'command': function('ale_linters#pony#ponyc#GetCommand'),
 \   'callback': 'ale#handlers#pony#HandlePonycFormat',
 \})
diff --git a/ale_linters/prolog/swipl.vim b/ale_linters/prolog/swipl.vim
index 77261ede..5c601c40 100644
--- a/ale_linters/prolog/swipl.vim
+++ b/ale_linters/prolog/swipl.vim
@@ -94,7 +94,7 @@ endfunction
 call ale#linter#Define('prolog', {
 \   'name': 'swipl',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('prolog_swipl_executable'),
-\   'command_callback': 'ale_linters#prolog#swipl#GetCommand',
+\   'executable': {b -> ale#Var(b, 'prolog_swipl_executable')},
+\   'command': function('ale_linters#prolog#swipl#GetCommand'),
 \   'callback': 'ale_linters#prolog#swipl#Handle',
 \})
diff --git a/ale_linters/proto/protoc_gen_lint.vim b/ale_linters/proto/protoc_gen_lint.vim
index c8b5c331..c3d10935 100644
--- a/ale_linters/proto/protoc_gen_lint.vim
+++ b/ale_linters/proto/protoc_gen_lint.vim
@@ -22,6 +22,6 @@ call ale#linter#Define('proto', {
 \   'lint_file': 1,
 \   'output_stream': 'stderr',
 \   'executable': 'protoc',
-\   'command_callback': 'ale_linters#proto#protoc_gen_lint#GetCommand',
+\   'command': function('ale_linters#proto#protoc_gen_lint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsError',
 \})
diff --git a/ale_linters/pug/puglint.vim b/ale_linters/pug/puglint.vim
index 63208986..c4e0e233 100644
--- a/ale_linters/pug/puglint.vim
+++ b/ale_linters/pug/puglint.vim
@@ -33,10 +33,10 @@ endfunction
 
 call ale#linter#Define('pug', {
 \   'name': 'puglint',
-\   'executable_callback': ale#node#FindExecutableFunc('pug_puglint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'pug_puglint', [
 \       'node_modules/.bin/pug-lint',
-\   ]),
+\   ])},
 \   'output_stream': 'stderr',
-\   'command_callback': 'ale_linters#pug#puglint#GetCommand',
+\   'command': function('ale_linters#pug#puglint#GetCommand'),
 \   'callback': 'ale#handlers#unix#HandleAsError',
 \})
diff --git a/ale_linters/puppet/languageserver.vim b/ale_linters/puppet/languageserver.vim
index a3060e65..2078695f 100644
--- a/ale_linters/puppet/languageserver.vim
+++ b/ale_linters/puppet/languageserver.vim
@@ -30,8 +30,8 @@ endfunction
 call ale#linter#Define('puppet', {
 \   'name': 'languageserver',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('puppet_languageserver_executable'),
+\   'executable': {b -> ale#Var(b, 'puppet_languageserver_executable')},
 \   'command': '%e --stdio',
 \   'language': 'puppet',
-\   'project_root_callback': 'ale_linters#puppet#languageserver#GetProjectRoot',
+\   'project_root': function('ale_linters#puppet#languageserver#GetProjectRoot'),
 \})
diff --git a/ale_linters/puppet/puppet.vim b/ale_linters/puppet/puppet.vim
index 0e37bdbd..ae648615 100644
--- a/ale_linters/puppet/puppet.vim
+++ b/ale_linters/puppet/puppet.vim
@@ -30,8 +30,8 @@ endfunction
 
 call ale#linter#Define('puppet', {
 \   'name': 'puppet',
-\   'executable_callback': ale#VarFunc('puppet_puppet_executable'),
+\   'executable': {b -> ale#Var(b, 'puppet_puppet_executable')},
 \   'output_stream': 'stderr',
-\   'command_callback': 'ale_linters#puppet#puppet#GetCommand',
+\   'command': function('ale_linters#puppet#puppet#GetCommand'),
 \   'callback': 'ale_linters#puppet#puppet#Handle',
 \})
diff --git a/ale_linters/puppet/puppetlint.vim b/ale_linters/puppet/puppetlint.vim
index c9c16f5e..985d6a4d 100644
--- a/ale_linters/puppet/puppetlint.vim
+++ b/ale_linters/puppet/puppetlint.vim
@@ -12,7 +12,7 @@ endfunction
 
 call ale#linter#Define('puppet', {
 \   'name': 'puppetlint',
-\   'executable_callback': ale#VarFunc('puppet_puppetlint_executable'),
-\   'command_callback': 'ale_linters#puppet#puppetlint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'puppet_puppetlint_executable')},
+\   'command': function('ale_linters#puppet#puppetlint#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \})
diff --git a/ale_linters/pyrex/cython.vim b/ale_linters/pyrex/cython.vim
index d260698c..84382ba1 100644
--- a/ale_linters/pyrex/cython.vim
+++ b/ale_linters/pyrex/cython.vim
@@ -32,7 +32,7 @@ endfunction
 call ale#linter#Define('pyrex', {
 \   'name': 'cython',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('pyrex_cython_executable'),
-\   'command_callback': 'ale_linters#pyrex#cython#GetCommand',
+\   'executable': {b -> ale#Var(b, 'pyrex_cython_executable')},
+\   'command': function('ale_linters#pyrex#cython#GetCommand'),
 \   'callback': 'ale_linters#pyrex#cython#Handle',
 \})
diff --git a/ale_linters/python/bandit.vim b/ale_linters/python/bandit.vim
index 5c9500a6..554f5000 100644
--- a/ale_linters/python/bandit.vim
+++ b/ale_linters/python/bandit.vim
@@ -62,7 +62,7 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'bandit',
-\   'executable_callback': 'ale_linters#python#bandit#GetExecutable',
-\   'command_callback': 'ale_linters#python#bandit#GetCommand',
+\   'executable': function('ale_linters#python#bandit#GetExecutable'),
+\   'command': function('ale_linters#python#bandit#GetCommand'),
 \   'callback': 'ale_linters#python#bandit#Handle',
 \})
diff --git a/ale_linters/python/flake8.vim b/ale_linters/python/flake8.vim
index 076bd9c4..993d7adb 100644
--- a/ale_linters/python/flake8.vim
+++ b/ale_linters/python/flake8.vim
@@ -143,7 +143,7 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'flake8',
-\   'executable_callback': 'ale_linters#python#flake8#GetExecutable',
+\   'executable': function('ale_linters#python#flake8#GetExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#python#flake8#VersionCheck'},
 \       {'callback': 'ale_linters#python#flake8#GetCommand', 'output_stream': 'both'},
diff --git a/ale_linters/python/mypy.vim b/ale_linters/python/mypy.vim
index 0c90a3c7..c4c6507f 100644
--- a/ale_linters/python/mypy.vim
+++ b/ale_linters/python/mypy.vim
@@ -75,7 +75,7 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'mypy',
-\   'executable_callback': 'ale_linters#python#mypy#GetExecutable',
-\   'command_callback': 'ale_linters#python#mypy#GetCommand',
+\   'executable': function('ale_linters#python#mypy#GetExecutable'),
+\   'command': function('ale_linters#python#mypy#GetCommand'),
 \   'callback': 'ale_linters#python#mypy#Handle',
 \})
diff --git a/ale_linters/python/prospector.vim b/ale_linters/python/prospector.vim
index b01cec87..ee47012f 100644
--- a/ale_linters/python/prospector.vim
+++ b/ale_linters/python/prospector.vim
@@ -93,8 +93,8 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'prospector',
-\   'executable_callback': 'ale_linters#python#prospector#GetExecutable',
-\   'command_callback': 'ale_linters#python#prospector#GetCommand',
+\   'executable': function('ale_linters#python#prospector#GetExecutable'),
+\   'command': function('ale_linters#python#prospector#GetCommand'),
 \   'callback': 'ale_linters#python#prospector#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/python/pycodestyle.vim b/ale_linters/python/pycodestyle.vim
index f0269585..fb521bc1 100644
--- a/ale_linters/python/pycodestyle.vim
+++ b/ale_linters/python/pycodestyle.vim
@@ -69,7 +69,7 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'pycodestyle',
-\   'executable_callback': 'ale_linters#python#pycodestyle#GetExecutable',
-\   'command_callback': 'ale_linters#python#pycodestyle#GetCommand',
+\   'executable': function('ale_linters#python#pycodestyle#GetExecutable'),
+\   'command': function('ale_linters#python#pycodestyle#GetCommand'),
 \   'callback': 'ale_linters#python#pycodestyle#Handle',
 \})
diff --git a/ale_linters/python/pydocstyle.vim b/ale_linters/python/pydocstyle.vim
index 177f5e0f..3901db4d 100644
--- a/ale_linters/python/pydocstyle.vim
+++ b/ale_linters/python/pydocstyle.vim
@@ -67,7 +67,7 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'pydocstyle',
-\   'executable_callback': 'ale_linters#python#pydocstyle#GetExecutable',
-\   'command_callback': 'ale_linters#python#pydocstyle#GetCommand',
+\   'executable': function('ale_linters#python#pydocstyle#GetExecutable'),
+\   'command': function('ale_linters#python#pydocstyle#GetCommand'),
 \   'callback': 'ale_linters#python#pydocstyle#Handle',
 \})
diff --git a/ale_linters/python/pyflakes.vim b/ale_linters/python/pyflakes.vim
index 091408d5..b5127022 100644
--- a/ale_linters/python/pyflakes.vim
+++ b/ale_linters/python/pyflakes.vim
@@ -43,8 +43,8 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'pyflakes',
-\   'executable_callback': 'ale_linters#python#pyflakes#GetExecutable',
-\   'command_callback': 'ale_linters#python#pyflakes#GetCommand',
+\   'executable': function('ale_linters#python#pyflakes#GetExecutable'),
+\   'command': function('ale_linters#python#pyflakes#GetCommand'),
 \   'callback': 'ale_linters#python#pyflakes#Handle',
 \   'output_stream': 'both',
 \})
diff --git a/ale_linters/python/pylama.vim b/ale_linters/python/pylama.vim
index 4ad25c0f..38dd2836 100644
--- a/ale_linters/python/pylama.vim
+++ b/ale_linters/python/pylama.vim
@@ -85,8 +85,8 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'pylama',
-\   'executable_callback': 'ale_linters#python#pylama#GetExecutable',
-\   'command_callback': 'ale_linters#python#pylama#GetCommand',
+\   'executable': function('ale_linters#python#pylama#GetExecutable'),
+\   'command': function('ale_linters#python#pylama#GetCommand'),
 \   'callback': 'ale_linters#python#pylama#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/python/pylint.vim b/ale_linters/python/pylint.vim
index f0f79cd7..57e82691 100644
--- a/ale_linters/python/pylint.vim
+++ b/ale_linters/python/pylint.vim
@@ -78,8 +78,8 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'pylint',
-\   'executable_callback': 'ale_linters#python#pylint#GetExecutable',
-\   'command_callback': 'ale_linters#python#pylint#GetCommand',
+\   'executable': function('ale_linters#python#pylint#GetExecutable'),
+\   'command': function('ale_linters#python#pylint#GetCommand'),
 \   'callback': 'ale_linters#python#pylint#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/python/pyls.vim b/ale_linters/python/pyls.vim
index 2c2ed94c..c7f91430 100644
--- a/ale_linters/python/pyls.vim
+++ b/ale_linters/python/pyls.vim
@@ -28,9 +28,9 @@ endfunction
 call ale#linter#Define('python', {
 \   'name': 'pyls',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#python#pyls#GetExecutable',
-\   'command_callback': 'ale_linters#python#pyls#GetCommand',
-\   'project_root_callback': 'ale#python#FindProjectRoot',
+\   'executable': function('ale_linters#python#pyls#GetExecutable'),
+\   'command': function('ale_linters#python#pyls#GetCommand'),
+\   'project_root': function('ale#python#FindProjectRoot'),
 \   'completion_filter': 'ale#completion#python#CompletionItemFilter',
-\   'lsp_config_callback': ale#VarFunc('python_pyls_config'),
+\   'lsp_config': {b -> ale#Var(b, 'python_pyls_config')},
 \})
diff --git a/ale_linters/python/pyre.vim b/ale_linters/python/pyre.vim
index adc185f2..4edd80f7 100644
--- a/ale_linters/python/pyre.vim
+++ b/ale_linters/python/pyre.vim
@@ -27,8 +27,8 @@ endfunction
 call ale#linter#Define('python', {
 \   'name': 'pyre',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#python#pyre#GetExecutable',
-\   'command_callback': 'ale_linters#python#pyre#GetCommand',
-\   'project_root_callback': 'ale#python#FindProjectRoot',
+\   'executable': function('ale_linters#python#pyre#GetExecutable'),
+\   'command': function('ale_linters#python#pyre#GetCommand'),
+\   'project_root': function('ale#python#FindProjectRoot'),
 \   'completion_filter': 'ale#completion#python#CompletionItemFilter',
 \})
diff --git a/ale_linters/python/vulture.vim b/ale_linters/python/vulture.vim
index b3908b80..d328d262 100644
--- a/ale_linters/python/vulture.vim
+++ b/ale_linters/python/vulture.vim
@@ -73,8 +73,8 @@ endfunction
 
 call ale#linter#Define('python', {
 \   'name': 'vulture',
-\   'executable_callback': 'ale_linters#python#vulture#GetExecutable',
-\   'command_callback': 'ale_linters#python#vulture#GetCommand',
+\   'executable': function('ale_linters#python#vulture#GetExecutable'),
+\   'command': function('ale_linters#python#vulture#GetCommand'),
 \   'callback': 'ale_linters#python#vulture#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/qml/qmlfmt.vim b/ale_linters/qml/qmlfmt.vim
index 12f3e97b..11cc9413 100644
--- a/ale_linters/qml/qmlfmt.vim
+++ b/ale_linters/qml/qmlfmt.vim
@@ -19,7 +19,7 @@ endfunction
 call ale#linter#Define('qml', {
 \   'name': 'qmlfmt',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('qml_qmlfmt_executable'),
+\   'executable': {b -> ale#Var(b, 'qml_qmlfmt_executable')},
 \   'command': '%e -e',
 \   'callback': 'ale_linters#qml#qmlfmt#Handle',
 \})
diff --git a/ale_linters/r/lintr.vim b/ale_linters/r/lintr.vim
index 8f74c9b8..3164c06f 100644
--- a/ale_linters/r/lintr.vim
+++ b/ale_linters/r/lintr.vim
@@ -29,7 +29,7 @@ endfunction
 call ale#linter#Define('r', {
 \   'name': 'lintr',
 \   'executable': 'Rscript',
-\   'command_callback': 'ale_linters#r#lintr#GetCommand',
+\   'command': function('ale_linters#r#lintr#GetCommand'),
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'output_stream': 'both',
 \})
diff --git a/ale_linters/reason/ols.vim b/ale_linters/reason/ols.vim
index 4e5bd395..66137e1b 100644
--- a/ale_linters/reason/ols.vim
+++ b/ale_linters/reason/ols.vim
@@ -7,8 +7,8 @@ call ale#Set('reason_ols_use_global', get(g:, 'ale_use_global_executables', 0))
 call ale#linter#Define('reason', {
 \   'name': 'ols',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale#handlers#ols#GetExecutable',
-\   'command_callback': 'ale#handlers#ols#GetCommand',
+\   'executable': function('ale#handlers#ols#GetExecutable'),
+\   'command': function('ale#handlers#ols#GetCommand'),
 \   'language_callback': 'ale#handlers#ols#GetLanguage',
-\   'project_root_callback': 'ale#handlers#ols#GetProjectRoot',
+\   'project_root': function('ale#handlers#ols#GetProjectRoot'),
 \})
diff --git a/ale_linters/rst/rstcheck.vim b/ale_linters/rst/rstcheck.vim
index 8504738b..39e11d6e 100644
--- a/ale_linters/rst/rstcheck.vim
+++ b/ale_linters/rst/rstcheck.vim
@@ -32,7 +32,7 @@ endfunction
 call ale#linter#Define('rst', {
 \   'name': 'rstcheck',
 \   'executable': 'rstcheck',
-\   'command_callback': 'ale_linters#rst#rstcheck#GetCommand',
+\   'command': function('ale_linters#rst#rstcheck#GetCommand'),
 \   'callback': 'ale_linters#rst#rstcheck#Handle',
 \   'output_stream': 'both',
 \})
diff --git a/ale_linters/rst/textlint.vim b/ale_linters/rst/textlint.vim
index a14411cf..56dd8db8 100644
--- a/ale_linters/rst/textlint.vim
+++ b/ale_linters/rst/textlint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('rst', {
 \   'name': 'textlint',
-\   'executable_callback': 'ale#handlers#textlint#GetExecutable',
-\   'command_callback': 'ale#handlers#textlint#GetCommand',
+\   'executable': function('ale#handlers#textlint#GetExecutable'),
+\   'command': function('ale#handlers#textlint#GetCommand'),
 \   'callback': 'ale#handlers#textlint#HandleTextlintOutput',
 \})
diff --git a/ale_linters/ruby/brakeman.vim b/ale_linters/ruby/brakeman.vim
index 122e0b5b..a8088080 100644
--- a/ale_linters/ruby/brakeman.vim
+++ b/ale_linters/ruby/brakeman.vim
@@ -44,8 +44,8 @@ endfunction
 
 call ale#linter#Define('ruby', {
 \    'name': 'brakeman',
-\    'executable_callback': ale#VarFunc('ruby_brakeman_executable'),
-\    'command_callback': 'ale_linters#ruby#brakeman#GetCommand',
+\    'executable': {b -> ale#Var(b, 'ruby_brakeman_executable')},
+\    'command': function('ale_linters#ruby#brakeman#GetCommand'),
 \    'callback': 'ale_linters#ruby#brakeman#Handle',
 \    'lint_file': 1,
 \})
diff --git a/ale_linters/ruby/rails_best_practices.vim b/ale_linters/ruby/rails_best_practices.vim
index 20cadca8..680cc364 100644
--- a/ale_linters/ruby/rails_best_practices.vim
+++ b/ale_linters/ruby/rails_best_practices.vim
@@ -42,8 +42,8 @@ endfunction
 
 call ale#linter#Define('ruby', {
 \    'name': 'rails_best_practices',
-\    'executable_callback': ale#VarFunc('ruby_rails_best_practices_executable'),
-\    'command_callback': 'ale_linters#ruby#rails_best_practices#GetCommand',
+\    'executable': {b -> ale#Var(b, 'ruby_rails_best_practices_executable')},
+\    'command': function('ale_linters#ruby#rails_best_practices#GetCommand'),
 \    'callback': 'ale_linters#ruby#rails_best_practices#Handle',
 \    'lint_file': 1,
 \})
diff --git a/ale_linters/ruby/reek.vim b/ale_linters/ruby/reek.vim
index 53363d31..26f6e36c 100644
--- a/ale_linters/ruby/reek.vim
+++ b/ale_linters/ruby/reek.vim
@@ -69,7 +69,7 @@ endfunction
 
 call ale#linter#Define('ruby', {
 \   'name': 'reek',
-\   'executable_callback': ale#VarFunc('ruby_reek_executable'),
+\   'executable': {b -> ale#Var(b, 'ruby_reek_executable')},
 \   'command_chain': [
 \       {'callback': 'ale_linters#ruby#reek#VersionCheck'},
 \       {'callback': 'ale_linters#ruby#reek#GetCommand'},
diff --git a/ale_linters/ruby/rubocop.vim b/ale_linters/ruby/rubocop.vim
index 790ca82c..8b9e9c84 100644
--- a/ale_linters/ruby/rubocop.vim
+++ b/ale_linters/ruby/rubocop.vim
@@ -25,7 +25,7 @@ endfunction
 
 call ale#linter#Define('ruby', {
 \   'name': 'rubocop',
-\   'executable_callback': ale#VarFunc('ruby_rubocop_executable'),
-\   'command_callback': 'ale_linters#ruby#rubocop#GetCommand',
+\   'executable': {b -> ale#Var(b, 'ruby_rubocop_executable')},
+\   'command': function('ale_linters#ruby#rubocop#GetCommand'),
 \   'callback': 'ale#ruby#HandleRubocopOutput',
 \})
diff --git a/ale_linters/ruby/ruby.vim b/ale_linters/ruby/ruby.vim
index 2bc4ec4b..2dc55eb0 100644
--- a/ale_linters/ruby/ruby.vim
+++ b/ale_linters/ruby/ruby.vim
@@ -5,7 +5,7 @@ call ale#Set('ruby_ruby_executable', 'ruby')
 
 call ale#linter#Define('ruby', {
 \   'name': 'ruby',
-\   'executable_callback': ale#VarFunc('ruby_ruby_executable'),
+\   'executable': {b -> ale#Var(b, 'ruby_ruby_executable')},
 \   'command': '%e -w -c -T1 %t',
 \   'output_stream': 'stderr',
 \   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
diff --git a/ale_linters/ruby/solargraph.vim b/ale_linters/ruby/solargraph.vim
index 5ff0a759..bf54a55c 100644
--- a/ale_linters/ruby/solargraph.vim
+++ b/ale_linters/ruby/solargraph.vim
@@ -15,8 +15,8 @@ call ale#linter#Define('ruby', {
 \   'name': 'solargraph',
 \   'lsp': 'stdio',
 \   'language': 'ruby',
-\   'executable_callback': ale#VarFunc('ruby_solargraph_executable'),
-\   'command_callback': 'ale_linters#ruby#solargraph#GetCommand',
-\   'project_root_callback': 'ale#ruby#FindProjectRoot',
-\   'initialization_options_callback': ale#VarFunc('ruby_solargraph_options'),
+\   'executable': {b -> ale#Var(b, 'ruby_solargraph_executable')},
+\   'command': function('ale_linters#ruby#solargraph#GetCommand'),
+\   'project_root': function('ale#ruby#FindProjectRoot'),
+\   'initialization_options': {b -> ale#Var(b, 'ruby_solargraph_options')},
 \})
diff --git a/ale_linters/ruby/standardrb.vim b/ale_linters/ruby/standardrb.vim
index 95e10934..f075a7d5 100644
--- a/ale_linters/ruby/standardrb.vim
+++ b/ale_linters/ruby/standardrb.vim
@@ -17,7 +17,7 @@ endfunction
 " standardrb is based on RuboCop so the callback is the same
 call ale#linter#Define('ruby', {
 \   'name': 'standardrb',
-\   'executable_callback': ale#VarFunc('ruby_standardrb_executable'),
-\   'command_callback': 'ale_linters#ruby#standardrb#GetCommand',
+\   'executable': {b -> ale#Var(b, 'ruby_standardrb_executable')},
+\   'command': function('ale_linters#ruby#standardrb#GetCommand'),
 \   'callback': 'ale#ruby#HandleRubocopOutput',
 \})
diff --git a/ale_linters/rust/cargo.vim b/ale_linters/rust/cargo.vim
index cf6187f8..b4eabfae 100644
--- a/ale_linters/rust/cargo.vim
+++ b/ale_linters/rust/cargo.vim
@@ -93,7 +93,7 @@ endfunction
 
 call ale#linter#Define('rust', {
 \   'name': 'cargo',
-\   'executable_callback': 'ale_linters#rust#cargo#GetCargoExecutable',
+\   'executable': function('ale_linters#rust#cargo#GetCargoExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#rust#cargo#VersionCheck'},
 \       {'callback': 'ale_linters#rust#cargo#GetCommand'},
diff --git a/ale_linters/rust/rls.vim b/ale_linters/rust/rls.vim
index 60dd3667..cf34b43c 100644
--- a/ale_linters/rust/rls.vim
+++ b/ale_linters/rust/rls.vim
@@ -19,7 +19,7 @@ endfunction
 call ale#linter#Define('rust', {
 \   'name': 'rls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('rust_rls_executable'),
-\   'command_callback': 'ale_linters#rust#rls#GetCommand',
-\   'project_root_callback': 'ale_linters#rust#rls#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'rust_rls_executable')},
+\   'command': function('ale_linters#rust#rls#GetCommand'),
+\   'project_root': function('ale_linters#rust#rls#GetProjectRoot'),
 \})
diff --git a/ale_linters/rust/rustc.vim b/ale_linters/rust/rustc.vim
index 33fb72f4..f140b58b 100644
--- a/ale_linters/rust/rustc.vim
+++ b/ale_linters/rust/rustc.vim
@@ -27,7 +27,7 @@ endfunction
 call ale#linter#Define('rust', {
 \   'name': 'rustc',
 \   'executable': 'rustc',
-\   'command_callback': 'ale_linters#rust#rustc#RustcCommand',
+\   'command': function('ale_linters#rust#rustc#RustcCommand'),
 \   'callback': 'ale#handlers#rust#HandleRustErrors',
 \   'output_stream': 'stderr',
 \})
diff --git a/ale_linters/sass/sasslint.vim b/ale_linters/sass/sasslint.vim
index 8d24185d..17cd3667 100644
--- a/ale_linters/sass/sasslint.vim
+++ b/ale_linters/sass/sasslint.vim
@@ -22,7 +22,7 @@ endfunction
 
 call ale#linter#Define('sass', {
 \   'name': 'sasslint',
-\   'executable_callback': 'ale_linters#sass#sasslint#GetExecutable',
-\   'command_callback': 'ale_linters#sass#sasslint#GetCommand',
+\   'executable': function('ale_linters#sass#sasslint#GetExecutable'),
+\   'command': function('ale_linters#sass#sasslint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleCSSLintFormat',
 \})
diff --git a/ale_linters/sass/stylelint.vim b/ale_linters/sass/stylelint.vim
index b6286f18..7b14c6b4 100644
--- a/ale_linters/sass/stylelint.vim
+++ b/ale_linters/sass/stylelint.vim
@@ -5,9 +5,9 @@ call ale#Set('sass_stylelint_use_global', get(g:, 'ale_use_global_executables',
 
 call ale#linter#Define('sass', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('sass_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'sass_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
+\   ])},
 \   'command': '%e --stdin-filename %s',
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/scala/fsc.vim b/ale_linters/scala/fsc.vim
index fbdce20e..94135235 100644
--- a/ale_linters/scala/fsc.vim
+++ b/ale_linters/scala/fsc.vim
@@ -7,7 +7,7 @@ endfunction
 
 call ale#linter#Define('scala', {
 \   'name': 'fsc',
-\   'executable_callback': {buf -> s:IsSbt(buf) ? '' : 'fsc'},
+\   'executable': {buf -> s:IsSbt(buf) ? '' : 'fsc'},
 \   'command': '%e -Ystop-after:parser %t',
 \   'callback': 'ale#handlers#scala#HandleScalacLintFormat',
 \   'output_stream': 'stderr',
diff --git a/ale_linters/scala/sbtserver.vim b/ale_linters/scala/sbtserver.vim
index 694241d7..d4f137c2 100644
--- a/ale_linters/scala/sbtserver.vim
+++ b/ale_linters/scala/sbtserver.vim
@@ -25,7 +25,7 @@ endfunction
 call ale#linter#Define('scala', {
 \   'name': 'sbtserver',
 \   'lsp': 'socket',
-\   'address_callback': 'ale_linters#scala#sbtserver#GetAddress',
+\   'address': function('ale_linters#scala#sbtserver#GetAddress'),
 \   'language': 'scala',
-\   'project_root_callback': 'ale_linters#scala#sbtserver#GetProjectRoot',
+\   'project_root': function('ale_linters#scala#sbtserver#GetProjectRoot'),
 \})
diff --git a/ale_linters/scala/scalac.vim b/ale_linters/scala/scalac.vim
index 3dbdd925..1dd579b4 100644
--- a/ale_linters/scala/scalac.vim
+++ b/ale_linters/scala/scalac.vim
@@ -8,7 +8,7 @@ endfunction
 
 call ale#linter#Define('scala', {
 \   'name': 'scalac',
-\   'executable_callback': {buf -> s:IsSbt(buf) ? '' : 'scalac'},
+\   'executable': {buf -> s:IsSbt(buf) ? '' : 'scalac'},
 \   'command': '%e -Ystop-after:parser %t',
 \   'callback': 'ale#handlers#scala#HandleScalacLintFormat',
 \   'output_stream': 'stderr',
diff --git a/ale_linters/scala/scalastyle.vim b/ale_linters/scala/scalastyle.vim
index 42228cf6..6e9e4c13 100644
--- a/ale_linters/scala/scalastyle.vim
+++ b/ale_linters/scala/scalastyle.vim
@@ -81,6 +81,6 @@ call ale#linter#Define('scala', {
 \   'name': 'scalastyle',
 \   'executable': 'scalastyle',
 \   'output_stream': 'stdout',
-\   'command_callback': 'ale_linters#scala#scalastyle#GetCommand',
+\   'command': function('ale_linters#scala#scalastyle#GetCommand'),
 \   'callback': 'ale_linters#scala#scalastyle#Handle',
 \})
diff --git a/ale_linters/scss/sasslint.vim b/ale_linters/scss/sasslint.vim
index 8b725ba6..cf13546e 100644
--- a/ale_linters/scss/sasslint.vim
+++ b/ale_linters/scss/sasslint.vim
@@ -22,7 +22,7 @@ endfunction
 
 call ale#linter#Define('scss', {
 \   'name': 'sasslint',
-\   'executable_callback': 'ale_linters#scss#sasslint#GetExecutable',
-\   'command_callback': 'ale_linters#scss#sasslint#GetCommand',
+\   'executable': function('ale_linters#scss#sasslint#GetExecutable'),
+\   'command': function('ale_linters#scss#sasslint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleCSSLintFormat',
 \})
diff --git a/ale_linters/scss/stylelint.vim b/ale_linters/scss/stylelint.vim
index 2bffa8e1..b5b21536 100644
--- a/ale_linters/scss/stylelint.vim
+++ b/ale_linters/scss/stylelint.vim
@@ -11,9 +11,9 @@ endfunction
 
 call ale#linter#Define('scss', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('scss_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'scss_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
-\   'command_callback': 'ale_linters#scss#stylelint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#scss#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/sh/language_server.vim b/ale_linters/sh/language_server.vim
index 385d1119..5a3b0e9a 100644
--- a/ale_linters/sh/language_server.vim
+++ b/ale_linters/sh/language_server.vim
@@ -26,7 +26,7 @@ endfunction
 call ale#linter#Define('sh', {
 \   'name': 'language_server',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#sh#language_server#GetExecutable',
-\   'command_callback': 'ale_linters#sh#language_server#GetCommand',
-\   'project_root_callback': 'ale_linters#sh#language_server#GetProjectRoot',
+\   'executable': function('ale_linters#sh#language_server#GetExecutable'),
+\   'command': function('ale_linters#sh#language_server#GetCommand'),
+\   'project_root': function('ale_linters#sh#language_server#GetProjectRoot'),
 \})
diff --git a/ale_linters/sh/shell.vim b/ale_linters/sh/shell.vim
index cf5e4e6c..189dc21d 100644
--- a/ale_linters/sh/shell.vim
+++ b/ale_linters/sh/shell.vim
@@ -51,7 +51,7 @@ endfunction
 call ale#linter#Define('sh', {
 \   'name': 'shell',
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale_linters#sh#shell#GetExecutable',
-\   'command_callback': 'ale_linters#sh#shell#GetCommand',
+\   'executable': function('ale_linters#sh#shell#GetExecutable'),
+\   'command': function('ale_linters#sh#shell#GetCommand'),
 \   'callback': 'ale_linters#sh#shell#Handle',
 \})
diff --git a/ale_linters/sh/shellcheck.vim b/ale_linters/sh/shellcheck.vim
index 12864722..bb7048cd 100644
--- a/ale_linters/sh/shellcheck.vim
+++ b/ale_linters/sh/shellcheck.vim
@@ -108,7 +108,7 @@ endfunction
 
 call ale#linter#Define('sh', {
 \   'name': 'shellcheck',
-\   'executable_callback': 'ale_linters#sh#shellcheck#GetExecutable',
+\   'executable': function('ale_linters#sh#shellcheck#GetExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#sh#shellcheck#VersionCheck'},
 \       {'callback': 'ale_linters#sh#shellcheck#GetCommand'},
diff --git a/ale_linters/slim/slimlint.vim b/ale_linters/slim/slimlint.vim
index a27736f8..1a4008ae 100644
--- a/ale_linters/slim/slimlint.vim
+++ b/ale_linters/slim/slimlint.vim
@@ -50,6 +50,6 @@ endfunction
 call ale#linter#Define('slim', {
 \   'name': 'slimlint',
 \   'executable': 'slim-lint',
-\   'command_callback': 'ale_linters#slim#slimlint#GetCommand',
+\   'command': function('ale_linters#slim#slimlint#GetCommand'),
 \   'callback': 'ale_linters#slim#slimlint#Handle'
 \})
diff --git a/ale_linters/sml/smlnj.vim b/ale_linters/sml/smlnj.vim
index f15579ea..852ea170 100644
--- a/ale_linters/sml/smlnj.vim
+++ b/ale_linters/sml/smlnj.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('sml', {
 \   'name': 'smlnj',
-\   'executable_callback': 'ale#handlers#sml#GetExecutableSmlnjFile',
+\   'executable': function('ale#handlers#sml#GetExecutableSmlnjFile'),
 \   'command': 'sml',
 \   'callback': 'ale#handlers#sml#Handle',
 \})
diff --git a/ale_linters/sml/smlnj_cm.vim b/ale_linters/sml/smlnj_cm.vim
index bfa4bc05..9ad24af4 100644
--- a/ale_linters/sml/smlnj_cm.vim
+++ b/ale_linters/sml/smlnj_cm.vim
@@ -12,9 +12,9 @@ endfunction
 call ale#linter#Define('sml', {
 \   'name': 'smlnj_cm',
 \   'aliases': ['smlnj-cm'],
-\   'executable_callback': 'ale#handlers#sml#GetExecutableSmlnjCm',
+\   'executable': function('ale#handlers#sml#GetExecutableSmlnjCm'),
 \   'lint_file': 1,
-\   'command_callback': 'ale_linters#sml#smlnj_cm#GetCommand',
+\   'command': function('ale_linters#sml#smlnj_cm#GetCommand'),
 \   'callback': 'ale#handlers#sml#Handle',
 \})
 
diff --git a/ale_linters/spec/rpmlint.vim b/ale_linters/spec/rpmlint.vim
index 486bef1e..92ef4d63 100644
--- a/ale_linters/spec/rpmlint.vim
+++ b/ale_linters/spec/rpmlint.vim
@@ -72,7 +72,7 @@ endfunction
 
 call ale#linter#Define('spec', {
 \   'name': 'rpmlint',
-\   'executable_callback': ale#VarFunc('spec_rpmlint_executable'),
-\   'command_callback': 'ale_linters#spec#rpmlint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'spec_rpmlint_executable')},
+\   'command': function('ale_linters#spec#rpmlint#GetCommand'),
 \   'callback': 'ale_linters#spec#rpmlint#Handle',
 \})
diff --git a/ale_linters/stylus/stylelint.vim b/ale_linters/stylus/stylelint.vim
index 2256f3c0..ce6f9426 100644
--- a/ale_linters/stylus/stylelint.vim
+++ b/ale_linters/stylus/stylelint.vim
@@ -12,9 +12,9 @@ endfunction
 
 call ale#linter#Define('stylus', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('stylus_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'stylus_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
-\   'command_callback': 'ale_linters#stylus#stylelint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#stylus#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/sugarss/stylelint.vim b/ale_linters/sugarss/stylelint.vim
index 6b0adf5a..6c705e46 100644
--- a/ale_linters/sugarss/stylelint.vim
+++ b/ale_linters/sugarss/stylelint.vim
@@ -13,9 +13,9 @@ endfunction
 
 call ale#linter#Define('sugarss', {
 \   'name': 'stylelint',
-\   'executable_callback': ale#node#FindExecutableFunc('sugarss_stylelint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'sugarss_stylelint', [
 \       'node_modules/.bin/stylelint',
-\   ]),
-\   'command_callback': 'ale_linters#sugarss#stylelint#GetCommand',
+\   ])},
+\   'command': function('ale_linters#sugarss#stylelint#GetCommand'),
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})
diff --git a/ale_linters/swift/swiftlint.vim b/ale_linters/swift/swiftlint.vim
index 0f2ea8de..237c45d3 100644
--- a/ale_linters/swift/swiftlint.vim
+++ b/ale_linters/swift/swiftlint.vim
@@ -63,7 +63,7 @@ endfunction
 
 call ale#linter#Define('swift', {
 \   'name': 'swiftlint',
-\   'executable_callback': 'ale_linters#swift#swiftlint#GetExecutable',
-\   'command_callback': 'ale_linters#swift#swiftlint#GetCommand',
+\   'executable': function('ale_linters#swift#swiftlint#GetExecutable'),
+\   'command': function('ale_linters#swift#swiftlint#GetCommand'),
 \   'callback': 'ale_linters#swift#swiftlint#Handle',
 \})
diff --git a/ale_linters/tcl/nagelfar.vim b/ale_linters/tcl/nagelfar.vim
index 05fe581b..5a4940e1 100644
--- a/ale_linters/tcl/nagelfar.vim
+++ b/ale_linters/tcl/nagelfar.vim
@@ -32,8 +32,8 @@ endfunction
 call ale#linter#Define('tcl', {
 \   'name': 'nagelfar',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('tcl_nagelfar_executable'),
-\   'command_callback': 'ale_linters#tcl#nagelfar#GetCommand',
+\   'executable': {b -> ale#Var(b, 'tcl_nagelfar_executable')},
+\   'command': function('ale_linters#tcl#nagelfar#GetCommand'),
 \   'callback': 'ale_linters#tcl#nagelfar#Handle',
 \   'lint_file': 1,
 \})
diff --git a/ale_linters/terraform/tflint.vim b/ale_linters/terraform/tflint.vim
index 0d77835a..6d54a8b1 100644
--- a/ale_linters/terraform/tflint.vim
+++ b/ale_linters/terraform/tflint.vim
@@ -52,7 +52,7 @@ endfunction
 
 call ale#linter#Define('terraform', {
 \   'name': 'tflint',
-\   'executable_callback': ale#VarFunc('terraform_tflint_executable'),
-\   'command_callback': 'ale_linters#terraform#tflint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'terraform_tflint_executable')},
+\   'command': function('ale_linters#terraform#tflint#GetCommand'),
 \   'callback': 'ale_linters#terraform#tflint#Handle',
 \})
diff --git a/ale_linters/tex/chktex.vim b/ale_linters/tex/chktex.vim
index 7f1b0c72..160baf0d 100644
--- a/ale_linters/tex/chktex.vim
+++ b/ale_linters/tex/chktex.vim
@@ -49,6 +49,6 @@ endfunction
 call ale#linter#Define('tex', {
 \   'name': 'chktex',
 \   'executable': 'chktex',
-\   'command_callback': 'ale_linters#tex#chktex#GetCommand',
+\   'command': function('ale_linters#tex#chktex#GetCommand'),
 \   'callback': 'ale_linters#tex#chktex#Handle'
 \})
diff --git a/ale_linters/tex/lacheck.vim b/ale_linters/tex/lacheck.vim
index ee09fb41..19d69403 100644
--- a/ale_linters/tex/lacheck.vim
+++ b/ale_linters/tex/lacheck.vim
@@ -37,7 +37,7 @@ endfunction
 
 call ale#linter#Define('tex', {
 \   'name': 'lacheck',
-\   'executable_callback': ale#VarFunc('tex_lacheck_executable'),
+\   'executable': {b -> ale#Var(b, 'tex_lacheck_executable')},
 \   'command': '%e %t',
 \   'callback': 'ale_linters#tex#lacheck#Handle'
 \})
diff --git a/ale_linters/tex/textlint.vim b/ale_linters/tex/textlint.vim
index 0266ed85..5edac46d 100644
--- a/ale_linters/tex/textlint.vim
+++ b/ale_linters/tex/textlint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('tex', {
 \   'name': 'textlint',
-\   'executable_callback': 'ale#handlers#textlint#GetExecutable',
-\   'command_callback': 'ale#handlers#textlint#GetCommand',
+\   'executable': function('ale#handlers#textlint#GetExecutable'),
+\   'command': function('ale#handlers#textlint#GetCommand'),
 \   'callback': 'ale#handlers#textlint#HandleTextlintOutput',
 \})
diff --git a/ale_linters/text/textlint.vim b/ale_linters/text/textlint.vim
index 8fafdd7d..67c4e378 100644
--- a/ale_linters/text/textlint.vim
+++ b/ale_linters/text/textlint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('text', {
 \   'name': 'textlint',
-\   'executable_callback': 'ale#handlers#textlint#GetExecutable',
-\   'command_callback': 'ale#handlers#textlint#GetCommand',
+\   'executable': function('ale#handlers#textlint#GetExecutable'),
+\   'command': function('ale#handlers#textlint#GetCommand'),
 \   'callback': 'ale#handlers#textlint#HandleTextlintOutput',
 \})
diff --git a/ale_linters/thrift/thrift.vim b/ale_linters/thrift/thrift.vim
index 2f2086c9..345c7abe 100644
--- a/ale_linters/thrift/thrift.vim
+++ b/ale_linters/thrift/thrift.vim
@@ -80,9 +80,8 @@ endfunction
 
 call ale#linter#Define('thrift', {
 \   'name': 'thrift',
-\   'executable': 'thrift',
 \   'output_stream': 'both',
-\   'executable_callback': ale#VarFunc('thrift_thrift_executable'),
-\   'command_callback': 'ale_linters#thrift#thrift#GetCommand',
+\   'executable': {b -> ale#Var(b, 'thrift_thrift_executable')},
+\   'command': function('ale_linters#thrift#thrift#GetCommand'),
 \   'callback': 'ale_linters#thrift#thrift#Handle',
 \})
diff --git a/ale_linters/typescript/eslint.vim b/ale_linters/typescript/eslint.vim
index f1ae54e7..bf849337 100644
--- a/ale_linters/typescript/eslint.vim
+++ b/ale_linters/typescript/eslint.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('typescript', {
 \   'name': 'eslint',
-\   'executable_callback': 'ale#handlers#eslint#GetExecutable',
-\   'command_callback': 'ale#handlers#eslint#GetCommand',
+\   'executable': function('ale#handlers#eslint#GetExecutable'),
+\   'command': function('ale#handlers#eslint#GetCommand'),
 \   'callback': 'ale#handlers#eslint#Handle',
 \})
diff --git a/ale_linters/typescript/tslint.vim b/ale_linters/typescript/tslint.vim
index ccdca936..f70c2e45 100644
--- a/ale_linters/typescript/tslint.vim
+++ b/ale_linters/typescript/tslint.vim
@@ -69,7 +69,7 @@ endfunction
 
 call ale#linter#Define('typescript', {
 \   'name': 'tslint',
-\   'executable_callback': 'ale#handlers#tslint#GetExecutable',
-\   'command_callback': 'ale_linters#typescript#tslint#GetCommand',
+\   'executable': function('ale#handlers#tslint#GetExecutable'),
+\   'command': function('ale_linters#typescript#tslint#GetCommand'),
 \   'callback': 'ale_linters#typescript#tslint#Handle',
 \})
diff --git a/ale_linters/typescript/tsserver.vim b/ale_linters/typescript/tsserver.vim
index 7dc8fa85..840889f3 100644
--- a/ale_linters/typescript/tsserver.vim
+++ b/ale_linters/typescript/tsserver.vim
@@ -8,10 +8,10 @@ call ale#Set('typescript_tsserver_use_global', get(g:, 'ale_use_global_executabl
 call ale#linter#Define('typescript', {
 \   'name': 'tsserver',
 \   'lsp': 'tsserver',
-\   'executable_callback': ale#node#FindExecutableFunc('typescript_tsserver', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'typescript_tsserver', [
 \       'node_modules/.bin/tsserver',
-\   ]),
+\   ])},
 \   'command': '%e',
-\   'project_root_callback': 'ale#handlers#tsserver#GetProjectRoot',
+\   'project_root': function('ale#handlers#tsserver#GetProjectRoot'),
 \   'language': '',
 \})
diff --git a/ale_linters/verilog/iverilog.vim b/ale_linters/verilog/iverilog.vim
index c64a3be6..e081f33f 100644
--- a/ale_linters/verilog/iverilog.vim
+++ b/ale_linters/verilog/iverilog.vim
@@ -38,6 +38,6 @@ call ale#linter#Define('verilog', {
 \   'name': 'iverilog',
 \   'output_stream': 'stderr',
 \   'executable': 'iverilog',
-\   'command_callback': 'ale_linters#verilog#iverilog#GetCommand',
+\   'command': function('ale_linters#verilog#iverilog#GetCommand'),
 \   'callback': 'ale_linters#verilog#iverilog#Handle',
 \})
diff --git a/ale_linters/verilog/verilator.vim b/ale_linters/verilog/verilator.vim
index 18d99043..64bb6e41 100644
--- a/ale_linters/verilog/verilator.vim
+++ b/ale_linters/verilog/verilator.vim
@@ -53,7 +53,7 @@ call ale#linter#Define('verilog', {
 \   'name': 'verilator',
 \   'output_stream': 'stderr',
 \   'executable': 'verilator',
-\   'command_callback': 'ale_linters#verilog#verilator#GetCommand',
+\   'command': function('ale_linters#verilog#verilator#GetCommand'),
 \   'callback': 'ale_linters#verilog#verilator#Handle',
 \   'read_buffer': 0,
 \})
diff --git a/ale_linters/verilog/vlog.vim b/ale_linters/verilog/vlog.vim
index c7686291..37d21c4c 100644
--- a/ale_linters/verilog/vlog.vim
+++ b/ale_linters/verilog/vlog.vim
@@ -30,7 +30,7 @@ endfunction
 call ale#linter#Define('verilog', {
 \   'name': 'vlog',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('verilog_vlog_executable'),
-\   'command_callback': 'ale_linters#verilog#vlog#GetCommand',
+\   'executable': {b -> ale#Var(b, 'verilog_vlog_executable')},
+\   'command': function('ale_linters#verilog#vlog#GetCommand'),
 \   'callback': 'ale_linters#verilog#vlog#Handle',
 \})
diff --git a/ale_linters/verilog/xvlog.vim b/ale_linters/verilog/xvlog.vim
index 52498f8f..98b5aae7 100644
--- a/ale_linters/verilog/xvlog.vim
+++ b/ale_linters/verilog/xvlog.vim
@@ -29,7 +29,7 @@ endfunction
 call ale#linter#Define('verilog', {
 \   'name': 'xvlog',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('verilog_xvlog_executable'),
-\   'command_callback': 'ale_linters#verilog#xvlog#GetCommand',
+\   'executable': {b -> ale#Var(b, 'verilog_xvlog_executable')},
+\   'command': function('ale_linters#verilog#xvlog#GetCommand'),
 \   'callback': 'ale_linters#verilog#xvlog#Handle',
 \})
diff --git a/ale_linters/vhdl/ghdl.vim b/ale_linters/vhdl/ghdl.vim
index c21be242..b09e620b 100644
--- a/ale_linters/vhdl/ghdl.vim
+++ b/ale_linters/vhdl/ghdl.vim
@@ -31,7 +31,7 @@ endfunction
 call ale#linter#Define('vhdl', {
 \   'name': 'ghdl',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('vhdl_ghdl_executable'),
-\   'command_callback': 'ale_linters#vhdl#ghdl#GetCommand',
+\   'executable': {b -> ale#Var(b, 'vhdl_ghdl_executable')},
+\   'command': function('ale_linters#vhdl#ghdl#GetCommand'),
 \   'callback': 'ale_linters#vhdl#ghdl#Handle',
 \})
diff --git a/ale_linters/vhdl/vcom.vim b/ale_linters/vhdl/vcom.vim
index e4631b68..1914fd33 100644
--- a/ale_linters/vhdl/vcom.vim
+++ b/ale_linters/vhdl/vcom.vim
@@ -32,7 +32,7 @@ endfunction
 call ale#linter#Define('vhdl', {
 \   'name': 'vcom',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('vhdl_vcom_executable'),
-\   'command_callback': 'ale_linters#vhdl#vcom#GetCommand',
+\   'executable': {b -> ale#Var(b, 'vhdl_vcom_executable')},
+\   'command': function('ale_linters#vhdl#vcom#GetCommand'),
 \   'callback': 'ale_linters#vhdl#vcom#Handle',
 \})
diff --git a/ale_linters/vhdl/xvhdl.vim b/ale_linters/vhdl/xvhdl.vim
index 6e0d411d..8010ff14 100644
--- a/ale_linters/vhdl/xvhdl.vim
+++ b/ale_linters/vhdl/xvhdl.vim
@@ -31,7 +31,7 @@ endfunction
 call ale#linter#Define('vhdl', {
 \   'name': 'xvhdl',
 \   'output_stream': 'stdout',
-\   'executable_callback': ale#VarFunc('vhdl_xvhdl_executable'),
-\   'command_callback': 'ale_linters#vhdl#xvhdl#GetCommand',
+\   'executable': {b -> ale#Var(b, 'vhdl_xvhdl_executable')},
+\   'command': function('ale_linters#vhdl#xvhdl#GetCommand'),
 \   'callback': 'ale_linters#vhdl#xvhdl#Handle',
 \})
diff --git a/ale_linters/vim/ale_custom_linting_rules.vim b/ale_linters/vim/ale_custom_linting_rules.vim
index 3abe5d4b..822eb30a 100644
--- a/ale_linters/vim/ale_custom_linting_rules.vim
+++ b/ale_linters/vim/ale_custom_linting_rules.vim
@@ -58,8 +58,8 @@ endfunction
 
 call ale#linter#Define('vim', {
 \   'name': 'ale_custom_linting_rules',
-\   'executable_callback': 'ale_linters#vim#ale_custom_linting_rules#GetExecutable',
-\   'command_callback': 'ale_linters#vim#ale_custom_linting_rules#GetCommand',
+\   'executable': function('ale_linters#vim#ale_custom_linting_rules#GetExecutable'),
+\   'command': function('ale_linters#vim#ale_custom_linting_rules#GetCommand'),
 \   'callback': 'ale_linters#vim#ale_custom_linting_rules#Handle',
 \   'read_buffer': 0,
 \})
diff --git a/ale_linters/vim/vint.vim b/ale_linters/vim/vint.vim
index cf2d4afd..3808c47e 100644
--- a/ale_linters/vim/vint.vim
+++ b/ale_linters/vim/vint.vim
@@ -65,7 +65,7 @@ endfunction
 
 call ale#linter#Define('vim', {
 \   'name': 'vint',
-\   'executable_callback': 'ale_linters#vim#vint#GetExecutable',
+\   'executable': function('ale_linters#vim#vint#GetExecutable'),
 \   'command_chain': [
 \       {'callback': 'ale_linters#vim#vint#VersionCommand', 'output_stream': 'stderr'},
 \       {'callback': 'ale_linters#vim#vint#GetCommand', 'output_stream': 'stdout'},
diff --git a/ale_linters/vue/vls.vim b/ale_linters/vue/vls.vim
index 7116128b..ac451f3c 100644
--- a/ale_linters/vue/vls.vim
+++ b/ale_linters/vue/vls.vim
@@ -13,10 +13,10 @@ endfunction
 call ale#linter#Define('vue', {
 \   'name': 'vls',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#node#FindExecutableFunc('vue_vls', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'vue_vls', [
 \       'node_modules/.bin/vls',
-\   ]),
+\   ])},
 \   'command': '%e --stdio',
 \   'language': 'vue',
-\   'project_root_callback': 'ale_linters#vue#vls#GetProjectRoot',
+\   'project_root': function('ale_linters#vue#vls#GetProjectRoot'),
 \})
diff --git a/ale_linters/xml/xmllint.vim b/ale_linters/xml/xmllint.vim
index b003b096..553d0883 100644
--- a/ale_linters/xml/xmllint.vim
+++ b/ale_linters/xml/xmllint.vim
@@ -59,7 +59,7 @@ endfunction
 call ale#linter#Define('xml', {
 \   'name': 'xmllint',
 \   'output_stream': 'stderr',
-\   'executable_callback': ale#VarFunc('xml_xmllint_executable'),
-\   'command_callback': 'ale_linters#xml#xmllint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'xml_xmllint_executable')},
+\   'command': function('ale_linters#xml#xmllint#GetCommand'),
 \   'callback': 'ale_linters#xml#xmllint#Handle',
 \ })
diff --git a/ale_linters/yaml/swaglint.vim b/ale_linters/yaml/swaglint.vim
index 7362536e..1f140e37 100644
--- a/ale_linters/yaml/swaglint.vim
+++ b/ale_linters/yaml/swaglint.vim
@@ -32,9 +32,9 @@ endfunction
 
 call ale#linter#Define('yaml', {
 \   'name': 'swaglint',
-\   'executable_callback': ale#node#FindExecutableFunc('yaml_swaglint', [
+\   'executable': {b -> ale#node#FindExecutable(b, 'yaml_swaglint', [
 \       'node_modules/.bin/swaglint',
-\   ]),
+\   ])},
 \   'command': '%e -r compact --stdin',
 \   'callback': 'ale_linters#yaml#swaglint#Handle',
 \})
diff --git a/ale_linters/yaml/yamllint.vim b/ale_linters/yaml/yamllint.vim
index 9d2cc7c2..bedb7bf1 100644
--- a/ale_linters/yaml/yamllint.vim
+++ b/ale_linters/yaml/yamllint.vim
@@ -44,7 +44,7 @@ endfunction
 
 call ale#linter#Define('yaml', {
 \   'name': 'yamllint',
-\   'executable_callback': ale#VarFunc('yaml_yamllint_executable'),
-\   'command_callback': 'ale_linters#yaml#yamllint#GetCommand',
+\   'executable': {b -> ale#Var(b, 'yaml_yamllint_executable')},
+\   'command': function('ale_linters#yaml#yamllint#GetCommand'),
 \   'callback': 'ale_linters#yaml#yamllint#Handle',
 \})
diff --git a/ale_linters/yang/yang_lsp.vim b/ale_linters/yang/yang_lsp.vim
index 45776f98..81fcaa0e 100644
--- a/ale_linters/yang/yang_lsp.vim
+++ b/ale_linters/yang/yang_lsp.vim
@@ -9,7 +9,7 @@ endfunction
 call ale#linter#Define('yang', {
 \   'name': 'yang_lsp',
 \   'lsp': 'stdio',
-\   'executable_callback': ale#VarFunc('yang_lsp_executable'),
-\   'project_root_callback': 'ale_linters#yang#yang_lsp#GetProjectRoot',
+\   'executable': {b -> ale#Var(b, 'yang_lsp_executable')},
+\   'project_root': function('ale_linters#yang#yang_lsp#GetProjectRoot'),
 \   'command': '%e',
 \})
diff --git a/autoload/ale.vim b/autoload/ale.vim
index f6c23d72..5aa5fbfc 100644
--- a/autoload/ale.vim
+++ b/autoload/ale.vim
@@ -169,11 +169,6 @@ function! ale#Var(buffer, variable_name) abort
     return get(l:vars, l:full_name, g:[l:full_name])
 endfunction
 
-" As above, but curry the arguments so only the buffer number is required.
-function! ale#VarFunc(variable_name) abort
-    return {buf -> ale#Var(buf, a:variable_name)}
-endfunction
-
 " Initialize a variable with a default value, if it isn't already set.
 "
 " Every variable name will be prefixed with 'ale_'.
diff --git a/autoload/ale/assert.vim b/autoload/ale/assert.vim
index 1b004649..6c2586a6 100644
--- a/autoload/ale/assert.vim
+++ b/autoload/ale/assert.vim
@@ -112,14 +112,6 @@ function! ale#assert#LSPLanguage(expected_language) abort
 endfunction
 
 function! ale#assert#LSPProject(expected_root) abort
-    let l:buffer = bufnr('')
-    let l:linter = s:GetLinter()
-    let l:root = ale#util#GetFunction(l:linter.project_root_callback)(l:buffer)
-
-    AssertEqual a:expected_root, l:root
-endfunction
-
-function! ale#assert#LSPProjectFull(expected_root) abort
     let l:buffer = bufnr('')
     let l:linter = s:GetLinter()
     let l:root = ale#lsp_linter#FindProjectRoot(l:buffer, l:linter)
@@ -130,7 +122,7 @@ endfunction
 function! ale#assert#LSPAddress(expected_address) abort
     let l:buffer = bufnr('')
     let l:linter = s:GetLinter()
-    let l:address = ale#util#GetFunction(l:linter.address_callback)(l:buffer)
+    let l:address = ale#linter#GetAddress(l:buffer, l:linter)
 
     AssertEqual a:expected_address, l:address
 endfunction
@@ -143,7 +135,6 @@ function! ale#assert#SetUpLinterTestCommands() abort
     command! -nargs=+ AssertLSPConfig :call ale#assert#LSPConfig(<args>)
     command! -nargs=+ AssertLSPLanguage :call ale#assert#LSPLanguage(<args>)
     command! -nargs=+ AssertLSPProject :call ale#assert#LSPProject(<args>)
-    command! -nargs=+ AssertLSPProjectFull :call ale#assert#LSPProjectFull(<args>)
     command! -nargs=+ AssertLSPAddress :call ale#assert#LSPAddress(<args>)
 endfunction
 
@@ -159,6 +150,12 @@ function! ale#assert#SetUpLinterTest(filetype, name) abort
     let l:prefix = 'ale_' . a:filetype . '_' . a:name
     let b:filter_expr = 'v:val[: len(l:prefix) - 1] is# l:prefix'
 
+    Save g:ale_lsp_root
+    let g:ale_lsp_root = {}
+
+    Save b:ale_lsp_root
+    unlet! b:ale_lsp_root
+
     Save g:ale_c_build_dir
     unlet! g:ale_c_build_dir
 
@@ -216,10 +213,6 @@ function! ale#assert#TearDownLinterTest() abort
         delcommand AssertLSPProject
     endif
 
-    if exists(':AssertLSPProjectFull')
-        delcommand AssertLSPProjectFull
-    endif
-
     if exists(':AssertLSPAddress')
         delcommand AssertLSPAddress
     endif
diff --git a/autoload/ale/linter.vim b/autoload/ale/linter.vim
index 74d5c14a..4937a6d7 100644
--- a/autoload/ale/linter.vim
+++ b/autoload/ale/linter.vim
@@ -340,6 +340,8 @@ function! ale#linter#PreProcess(filetype, linter) abort
         throw '`aliases` must be a List of String values'
     endif
 
+    " TODO: Emit deprecation warnings for deprecated options later.
+
     return l:obj
 endfunction
 
diff --git a/autoload/ale/node.vim b/autoload/ale/node.vim
index 5c579c75..f75280b7 100644
--- a/autoload/ale/node.vim
+++ b/autoload/ale/node.vim
@@ -23,11 +23,6 @@ function! ale#node#FindExecutable(buffer, base_var_name, path_list) abort
     return ale#Var(a:buffer, a:base_var_name . '_executable')
 endfunction
 
-" As above, but curry the arguments so only the buffer number is required.
-function! ale#node#FindExecutableFunc(base_var_name, path_list) abort
-    return {buf -> ale#node#FindExecutable(buf, a:base_var_name, a:path_list)}
-endfunction
-
 " Create a executable string which executes a Node.js script command with a
 " Node.js executable if needed.
 "
diff --git a/doc/ale.txt b/doc/ale.txt
index acf86fb1..16f7262d 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -3110,17 +3110,13 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          for computing the executable, accepting a buffer
                          number.
 
-                         This value will be used to check if the
-                         program requested is installed or not.
+                         This value will be used to check if the program
+                         requested is installed or not.
 
-                         Either this or the `executable_callback` argument
-                         must be provided.
-
-  `executable_callback  `  A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |String| should be
-                         returned for the executable to check. This can be
-                         used in place of `executable` when more complicated
-                         processing is needed.
+                         If an `executable` is not defined, the command will
+                         be run without checking if a program is executable
+                         first. Defining an executable path is recommended to
+                         avoid starting too many processes.
 
   `command`                A |String| for a command to run asynchronously, or a
                          |Funcref| for a function to call for computing the
@@ -3130,17 +3126,6 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          check, and will produce the lines of output given to
                          the `callback`.
 
-  `command_callback`       A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |String| should be
-                         returned for a command to run. This can be used in
-                         place of `command` when more complicated processing
-                         is needed.
-
-                         If an empty string is returned from the callback,
-                         no jobs for linting will be run for that linter.
-                         This can be used for skipping a linter call,
-                         say if no configuration file was found.
-
                                                             *ale-command-chain*
   `command_chain`          A |List| of |Dictionary| items defining a series
                          of commands to be run. At least one |Dictionary|
@@ -3226,22 +3211,20 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          linter will be defined as an LSP linter which keeps a
                          process for a language server running, and
                          communicates with it directly via a |channel|.
-                         `executable` or `executable_callback` must be set,
-                         and `command` or `command_callback` must be set.
+                         `executable` and `command` must be set.
 
                          When this argument is set to `'socket'`, then the
                          linter will be defined as an LSP linter via a TCP
-                         socket connection. Either `address` or
-                         `address_callback` must be set.
+                         socket connection. `address` must be set.
 
                          ALE will not start a server automatically.
 
-                         When this argument is not empty
-                         `project_root_callback` must be defined.
+                         When this argument is not empty `project_root` must
+                         be defined.
 
-                         `language` or `language_callback` can be defined to
-                         describe the language for a file. The filetype will
-                         be used as the language by default.
+                         `language` can be defined to describe the language
+                         for a file. The filetype will be used as the language
+                         by default.
 
                          LSP linters handle diagnostics automatically, so
                          the `callback` argument must not be defined.
@@ -3249,12 +3232,11 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          An optional `completion_filter` callback may be
                          defined for filtering completion results.
 
-                         An optional `initialization_options` or
-                         `initialization_options_callback` may be defined to
-                         pass initialization options to the LSP.
+                         `initialization_options` may be defined to pass
+                         initialization options to the LSP.
 
-                         An optional `lsp_config` or `lsp_config_callback` may
-                         be defined to pass configuration settings to the LSP.
+                         `lsp_config` may be defined to pass configuration
+                         settings to the LSP.
 
   `address`                A |String| representing an address to connect to,
                          or a |Funcref| accepting a buffer number and
@@ -3263,13 +3245,6 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          This argument must only be set if the `lsp` argument
                          is set to `'socket'`.
 
-  `address_callback`       A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |String| should be
-                         returned with an address to connect to.
-
-                         This argument must only be set if the `lsp` argument
-                         is set to `'socket'`.
-
   `project_root`           A |String| representing a path to the project for
                          the file being checked with the language server, or
                          a |Funcref| accepting a buffer number and returning
@@ -3281,27 +3256,15 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          This argument must only be set if the `lsp` argument
                          is also set to a non-empty string.
 
-  `project_root_callback`  A |String| or |Funcref| for a callback function
-                         accepting a buffer number and returning the
-                         `project_root` |String| as documented above.
-
   `language`               A |String| representing the name of the language
                          being checked, or a |Funcref| accepting a buffer
                          number and returning the |String|. This string will
                          be sent to the LSP to tell it what type of language
                          is being checked.
 
-                         If this or `language_callback` isn't set, the
-                         language will default to the value of the filetype
-                         given to |ale#linter#Define|.
-
-  `language_callback`      A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |String| should be
-                         returned representing the name of the language being
-                         checked.
-
-                         This option can be used instead of `language` if a
-                         linter can check multiple languages.
+                         If a language isn't provided, the language will
+                         default to the value of the filetype given to
+                         |ale#linter#Define|.
 
   `completion_filter`      A |String| or |Funcref| for a callback function
                          accepting a buffer number and a completion item.
@@ -3326,13 +3289,6 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          This will be fed (as JSON) to the LSP in the
                          initialize command.
 
-  `initialization_options_callback`
-                         A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |Dictionary| should be
-                         returned for initialization options to pass the LSP.
-                         This can be used in place of `initialization_options`
-                         when more complicated processing is needed.
-
   `lsp_config`             A |Dictionary| for configuring a language server,
                          or a |Funcref| for a callback function accepting
                          a buffer number and returning the |Dictionary|.
@@ -3340,23 +3296,12 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
                          This will be fed (as JSON) to the LSP in the
                          workspace/didChangeConfiguration command.
 
-  `lsp_config_callback`    A |String| or |Funcref| for a callback function
-                         accepting a buffer number. A |Dictionary| should be
-                         returned for configuration settings to pass the LSP.
-                         This can be used in place of `lsp_config` when more
-                         complicated processing is needed.
-
-  Only one of `command`, `command_callback`, or `command_chain` should be
-  specified. `command_callback` is generally recommended when a command string
-  needs to be generated dynamically, or any global options are used.
-  `command_chain` is recommended where any system calls need to be made to
-  retrieve some kind of information before running the final command.
+  Only one of `command` or `command_chain` should be specified.
 
   If temporary files or directories are created for commands run with
-  `command_callback` or `command_chain`, then these tempoary files or
-  directories can be managed by ALE, for automatic deletion.
-  See |ale#engine#ManageFile()| and |ale#engine#ManageDirectory| for more
-  information.
+  `command` or `command_chain`, then these temporary files or directories can
+  be managed by ALE, for automatic deletion.  See |ale#command#ManageFile()|
+  and |ale#command#ManageDirectory| for more information.
 
                                                    *ale-command-format-strings*
 
@@ -3374,16 +3319,16 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
   strings will reference the one temporary file. The temporary file will be
   created inside a temporary directory, and the entire temporary directory
   will be automatically deleted, following the behaviour of
-  |ale#engine#ManageDirectory|. This option can be used for some linters which
+  |ale#command#ManageDirectory|. This option can be used for some linters which
   do not support reading from stdin.
 
   For example: >
   'command': 'ghc -fno-code -v0 %t',
 <
   Any substring `%e` will be replaced with the escaped executable supplied
-  with `executable` or `executable_callback`. This provides a convenient way
-  to define a command string which needs to include a dynamic executable name,
-  but which is otherwise static.
+  with `executable`. This provides a convenient way to define a command string
+  which needs to include a dynamic executable name, but which is otherwise
+  static.
 
   For example: >
   'command': '%e --some-argument',
@@ -3394,7 +3339,7 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
 
   If a callback for a command generates part of a command string which might
   possibly contain `%%`, `%s`, `%t`, or `%e`, where the special formatting
-  behavior is not desired, the |ale#engine#EscapeCommandPart()| function can
+  behavior is not desired, the |ale#command#EscapeCommandPart()| function can
   be used to replace those characters to avoid formatting issues.
 
                                                   *ale-linter-loading-behavior*
diff --git a/test/lsp/test_lsp_root_detection.vader b/test/lsp/test_lsp_root_detection.vader
index 2575a62c..b7827248 100644
--- a/test/lsp/test_lsp_root_detection.vader
+++ b/test/lsp/test_lsp_root_detection.vader
@@ -16,48 +16,47 @@ Execute(The buffer-specific variable can be a string):
   let b:ale_lsp_root = '/some/path'
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull '/some/path'
+  AssertLSPProject '/some/path'
 
 Execute(The buffer-specific variable can be a dictionary):
   let b:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull '/some/path'
+  AssertLSPProject '/some/path'
 
 Execute(The buffer-specific variable can have funcrefs):
   let b:ale_lsp_root = {'clangd': function('Hook1'), 'golangserver': '/path'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull 'abc123'
+  AssertLSPProject 'abc123'
 
 Execute(The global variable can be a dictionary):
   let g:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull '/some/path'
+  AssertLSPProject '/some/path'
 
 Execute(The global variable can have funcrefs):
   let g:ale_lsp_root = {'clangd': function('Hook1'), 'golangserver': '/path'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull 'abc123'
+  AssertLSPProject 'abc123'
 
 Execute(The buffer-specific variable overrides the global variable):
   let b:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'}
   let g:ale_lsp_root = {'clangd': '/not/this/path', 'golangserver': '/elsewhere'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull '/some/path'
+  AssertLSPProject '/some/path'
 
 Execute(The global variable is queried if the buffer-specific has no value):
   let b:ale_lsp_root = {'golangserver': '/other/path'}
   let g:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/elsewhere'}
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull '/some/path'
-
+  AssertLSPProject '/some/path'
 
 Execute(The default hook value is acceptable):
   call ale#test#SetFilename('other-file.c')
 
-  AssertLSPProjectFull ''
+  AssertLSPProject ''