Simplify the code for most linters and tests with closures

ale_linters/c/clang.vim

@@ -4,17 +4,12 @@
 call ale#Set('c_clang_executable', 'clang')
 call ale#Set('c_clang_options', '-std=c11 -Wall')
 
-function! ale_linters#c#clang#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_clang_executable')
-endfunction
-
 function! ale_linters#c#clang#GetCommand(buffer, output) abort
     let l:cflags = ale#c#GetCFlags(a:buffer, a:output)
 
     " -iquote with the directory the file is in makes #include work for
     "  headers in the same directory.
-    return ale#Escape(ale_linters#c#clang#GetExecutable(a:buffer))
-    \   . ' -S -x c -fsyntax-only'
+    return '%e -S -x c -fsyntax-only'
     \   . ' -iquote ' . ale#Escape(fnamemodify(bufname(a:buffer), ':p:h'))
     \   . ale#Pad(l:cflags)
     \   . ale#Pad(ale#Var(a:buffer, 'c_clang_options')) . ' -'
@@ -23,7 +18,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'clang',
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale_linters#c#clang#GetExecutable',
+\   'executable_callback': ale#VarFunc('c_clang_executable'),
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#c#clang#GetCommand'}

ale_linters/c/clangd.vim

@@ -9,21 +9,14 @@ function! ale_linters#c#clangd#GetProjectRoot(buffer) abort
     return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
 endfunction
 
-function! ale_linters#c#clangd#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_clangd_executable')
-endfunction
-
 function! ale_linters#c#clangd#GetCommand(buffer) abort
-    let l:executable = ale_linters#c#clangd#GetExecutable(a:buffer)
-    let l:options = ale#Var(a:buffer, 'c_clangd_options')
-
-    return ale#Escape(l:executable) . (!empty(l:options) ? ' ' . l:options : '')
+    return '%e' . ale#Pad(ale#Var(a:buffer, 'c_clangd_options'))
 endfunction
 
 call ale#linter#Define('c', {
 \   'name': 'clangd',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#c#clangd#GetExecutable',
+\   'executable_callback': ale#VarFunc('c_clangd_executable'),
 \   'command_callback': 'ale_linters#c#clangd#GetCommand',
 \   'project_root_callback': 'ale_linters#c#clangd#GetProjectRoot',
 \})

ale_linters/c/clangtidy.vim

@@ -16,10 +16,6 @@ call ale#Set('c_clangtidy_checks', ['*'])
 call ale#Set('c_clangtidy_options', '')
 call ale#Set('c_build_dir', '')
 
-function! ale_linters#c#clangtidy#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_clangtidy_executable')
-endfunction
-
 function! s:GetBuildDirectory(buffer) abort
     " Don't include build directory for header files, as compile_commands.json
     " files don't consider headers to be translation units, and provide no
@@ -47,7 +43,7 @@ function! ale_linters#c#clangtidy#GetCommand(buffer) abort
     \   ? ale#Var(a:buffer, 'c_clangtidy_options')
     \   : ''
 
-    return ale#Escape(ale_linters#c#clangtidy#GetExecutable(a:buffer))
+    return '%e'
     \   . (!empty(l:checks) ? ' -checks=' . ale#Escape(l:checks) : '')
     \   . ' %s'
     \   . (!empty(l:build_dir) ? ' -p ' . ale#Escape(l:build_dir) : '')
@@ -57,7 +53,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'clangtidy',
 \   'output_stream': 'stdout',
-\   'executable_callback': 'ale_linters#c#clangtidy#GetExecutable',
+\   'executable_callback': ale#VarFunc('c_clangtidy_executable'),
 \   'command_callback': 'ale_linters#c#clangtidy#GetCommand',
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
 \   'lint_file': 1,

ale_linters/c/cppcheck.vim

@@ -4,10 +4,6 @@
 call ale#Set('c_cppcheck_executable', 'cppcheck')
 call ale#Set('c_cppcheck_options', '--enable=style')
 
-function! ale_linters#c#cppcheck#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_cppcheck_executable')
-endfunction
-
 function! ale_linters#c#cppcheck#GetCommand(buffer) abort
     " Search upwards from the file for compile_commands.json.
     "
@@ -23,8 +19,7 @@ function! ale_linters#c#cppcheck#GetCommand(buffer) abort
     \   : ''
 
     return l:cd_command
-    \   . ale#Escape(ale_linters#c#cppcheck#GetExecutable(a:buffer))
-    \   . ' -q --language=c '
+    \   . '%e -q --language=c '
     \   . l:compile_commands_option
     \   . ale#Var(a:buffer, 'c_cppcheck_options')
     \   . ' %t'
@@ -33,7 +28,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'cppcheck',
 \   'output_stream': 'both',
-\   'executable_callback': 'ale_linters#c#cppcheck#GetExecutable',
+\   'executable_callback': ale#VarFunc('c_cppcheck_executable'),
 \   'command_callback': 'ale_linters#c#cppcheck#GetCommand',
 \   'callback': 'ale#handlers#cppcheck#HandleCppCheckFormat',
 \})

ale_linters/c/cquery.vim

@@ -9,15 +9,6 @@ function! ale_linters#c#cquery#GetProjectRoot(buffer) abort
     return !empty(l:project_root) ? fnamemodify(l:project_root, ':h') : ''
 endfunction
 
-function! ale_linters#c#cquery#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_cquery_executable')
-endfunction
-
-function! ale_linters#c#cquery#GetCommand(buffer) abort
-    let l:executable = ale_linters#c#cquery#GetExecutable(a:buffer)
-    return ale#Escape(l:executable)
-endfunction
-
 function! ale_linters#c#cquery#GetInitializationOptions(buffer) abort
     return {'cacheDirectory': ale#Var(a:buffer, 'c_cquery_cache_directory')}
 endfunction
@@ -25,8 +16,8 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'cquery',
 \   'lsp': 'stdio',
-\   'executable_callback': 'ale_linters#c#cquery#GetExecutable',
-\   'command_callback': 'ale_linters#c#cquery#GetCommand',
+\   'executable_callback': ale#VarFunc('c_cquery_executable'),
+\   'command': '%e',
 \   'project_root_callback': 'ale_linters#c#cquery#GetProjectRoot',
 \   'initialization_options_callback': 'ale_linters#c#cquery#GetInitializationOptions',
 \})

ale_linters/c/flawfinder.vim

@@ -6,18 +6,12 @@ call ale#Set('c_flawfinder_options', '')
 call ale#Set('c_flawfinder_minlevel', 1)
 call ale#Set('c_flawfinder_error_severity', 6)
 
-function! ale_linters#c#flawfinder#GetExecutable(buffer) abort
-   return ale#Var(a:buffer, 'c_flawfinder_executable')
-endfunction
-
 function! ale_linters#c#flawfinder#GetCommand(buffer) abort
-
    " Set the minimum vulnerability level for flawfinder to bother with
    let l:minlevel = ' --minlevel=' . ale#Var(a:buffer, 'c_flawfinder_minlevel')
 
-   return ale#Escape(ale_linters#c#flawfinder#GetExecutable(a:buffer))
-   \  . ' -CDQS'
-   \  . ale#Var(a:buffer, 'c_flawfinder_options')
+   return '%e -CDQS'
+   \  . ale#Pad(ale#Var(a:buffer, 'c_flawfinder_options'))
    \  . l:minlevel
    \  . ' %t'
 endfunction
@@ -25,7 +19,7 @@ endfunction
 call ale#linter#Define('c', {
 \  'name': 'flawfinder',
 \  'output_stream': 'stdout',
-\  'executable_callback': 'ale_linters#c#flawfinder#GetExecutable',
+\  'executable_callback': ale#VarFunc('c_flawfinder_executable'),
 \  'command_callback': 'ale_linters#c#flawfinder#GetCommand',
 \  'callback': 'ale#handlers#flawfinder#HandleFlawfinderFormat',
 \})

ale_linters/c/gcc.vim

@@ -4,17 +4,12 @@
 call ale#Set('c_gcc_executable', 'gcc')
 call ale#Set('c_gcc_options', '-std=c11 -Wall')
 
-function! ale_linters#c#gcc#GetExecutable(buffer) abort
-    return ale#Var(a:buffer, 'c_gcc_executable')
-endfunction
-
 function! ale_linters#c#gcc#GetCommand(buffer, output) abort
     let l:cflags = ale#c#GetCFlags(a:buffer, a:output)
 
     " -iquote with the directory the file is in makes #include work for
     "  headers in the same directory.
-    return ale#Escape(ale_linters#c#gcc#GetExecutable(a:buffer))
-    \   . ' -S -x c -fsyntax-only'
+    return '%e -S -x c -fsyntax-only'
     \   . ' -iquote ' . ale#Escape(fnamemodify(bufname(a:buffer), ':p:h'))
     \   . ale#Pad(l:cflags)
     \   . ale#Pad(ale#Var(a:buffer, 'c_gcc_options')) . ' -'
@@ -23,7 +18,7 @@ endfunction
 call ale#linter#Define('c', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
-\   'executable_callback': 'ale_linters#c#gcc#GetExecutable',
+\   'executable_callback': ale#VarFunc('c_gcc_executable'),
 \   'command_chain': [
 \       {'callback': 'ale#c#GetMakeCommand', 'output_stream': 'stdout'},
 \       {'callback': 'ale_linters#c#gcc#GetCommand'}