First pass at optimizing ale to autoload (#80)

* First pass at optimizing ale to autoload

First off, the structure/function names should be revised a bit,
but I will wait for @w0rp's input before unifying the naming style.
Second off, the docs probably need some more work, I just did some
simple find-and-replace work.

With that said, this pull brings major performance gains for ale. On my
slowest system, fully loading ale and all its code takes around 150ms.

I have moved all of ale's autoload-able code to autoload/, and in
addition, implemented lazy-loading of linters. This brings load time on
that same system down to 5ms.

The only downside of lazy loading is that `g:ale_linters` cannot be
changed at runtime; however, it also speeds up performance at runtime by
simplfying the logic greatly.

Please let me know what you think!

Closes #59

* Address Travis/Vint errors

For some reason, ale isn't running vint for me...

* Incorporate feedback, make fixes

Lazy-loading logic is much improved.

* Add header comments; remove incorrect workaround

* Remove unneeded plugin guards

* Fix lazy-loading linter logic

Set the wrong variable....

* Fix capitialization

ale_linters/c/gcc.vim

@@ -12,7 +12,7 @@ if !exists('g:ale_c_gcc_options')
     let g:ale_c_gcc_options = '-Wall'
 endif
 
-call ALEAddLinter('c', {
+call ale#linter#Define('c', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
 \   'executable': 'gcc',

ale_linters/coffee/coffee.vim

@@ -7,7 +7,7 @@ endif
 
 let g:loaded_ale_linters_coffee_coffee = 1
 
-call ALEAddLinter('coffee', {
+call ale#linter#Define('coffee', {
 \   'name': 'coffee',
 \   'executable': 'coffee',
 \   'command': 'coffee -cp -s',

ale_linters/coffee/coffeelint.vim

@@ -44,7 +44,7 @@ function! ale_linters#coffee#coffeelint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('coffee', {
+call ale#linter#Define('coffee', {
 \   'name': 'coffeelint',
 \   'executable': 'coffeelint',
 \   'command': 'coffeelint --stdin --reporter csv',

ale_linters/cpp/gcc.vim

@@ -12,7 +12,7 @@ if !exists('g:ale_cpp_gcc_options')
     let g:ale_cpp_gcc_options = '-Wall'
 endif
 
-call ALEAddLinter('cpp', {
+call ale#linter#Define('cpp', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
 \   'executable': 'gcc',

ale_linters/css/csslint.vim

@@ -7,7 +7,7 @@ endif
 
 let g:loaded_ale_linters_css_csslint = 1
 
-call ALEAddLinter('css', {
+call ale#linter#Define('css', {
 \   'name': 'csslint',
 \   'executable': 'csslint',
 \   'command': g:ale#util#stdin_wrapper . ' .css csslint --format=compact',

ale_linters/d/dmd.vim

@@ -61,7 +61,7 @@ function! ale_linters#d#dmd#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('d', {
+call ale#linter#Define('d', {
 \   'name': 'dmd',
 \   'output_stream': 'stderr',
 \   'executable': 'dmd',

ale_linters/fortran/gcc.vim

@@ -60,7 +60,7 @@ function! ale_linters#fortran#gcc#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('fortran', {
+call ale#linter#Define('fortran', {
 \   'name': 'gcc',
 \   'output_stream': 'stderr',
 \   'executable': 'gcc',

ale_linters/haskell/ghc.vim

@@ -58,7 +58,7 @@ function! ale_linters#haskell#ghc#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('haskell', {
+call ale#linter#Define('haskell', {
 \   'name': 'ghc',
 \   'output_stream': 'stderr',
 \   'executable': 'ghc',
@@ -66,7 +66,7 @@ call ALEAddLinter('haskell', {
 \   'callback': 'ale_linters#haskell#ghc#Handle',
 \})
 
-call ALEAddLinter('haskell', {
+call ale#linter#Define('haskell', {
 \   'name': 'stack-ghc',
 \   'output_stream': 'stderr',
 \   'executable': 'stack',

ale_linters/html/htmlhint.vim

@@ -40,7 +40,7 @@ function! ale_linters#html#htmlhint#Handle(buffer, lines) abort
     return output
 endfunction
 
-call ALEAddLinter('html', {
+call ale#linter#Define('html', {
 \   'name': 'htmlhint',
 \   'executable': 'htmlhint',
 \   'command': 'htmlhint --format=unix stdin',

ale_linters/html/tidy.vim

@@ -71,7 +71,7 @@ function! ale_linters#html#tidy#Handle(buffer, lines) abort
     return output
 endfunction
 
-call ALEAddLinter('html', {
+call ale#linter#Define('html', {
 \   'name': 'tidy',
 \   'executable': g:ale_html_tidy_executable,
 \   'output_stream': 'stderr',

ale_linters/javascript/eslint.vim

@@ -49,14 +49,14 @@ function! ale_linters#javascript#eslint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('javascript', {
+call ale#linter#Define('javascript', {
 \   'name': 'eslint',
 \   'executable': g:ale_javascript_eslint_executable,
 \   'command': g:ale_javascript_eslint_executable . ' -f unix --stdin --stdin-filename %s',
 \   'callback': 'ale_linters#javascript#eslint#Handle',
 \})
 
-call ALEAddLinter('javascript.jsx', {
+call ale#linter#Define('javascript.jsx', {
 \   'name': 'eslint',
 \   'executable': g:ale_javascript_eslint_executable,
 \   'command': g:ale_javascript_eslint_executable . ' -f unix --stdin --stdin-filename %s',

ale_linters/javascript/jscs.vim

@@ -43,14 +43,14 @@ function! ale_linters#javascript#jscs#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('javascript', {
+call ale#linter#Define('javascript', {
 \   'name': 'jscs',
 \   'executable': 'jscs',
 \   'command': 'jscs -r unix -n -',
 \   'callback': 'ale_linters#javascript#jscs#Handle',
 \})
 
-call ALEAddLinter('javascript.jsx', {
+call ale#linter#Define('javascript.jsx', {
 \   'name': 'jscs',
 \   'executable': 'jscs',
 \   'command': 'jscs -r unix -n -',

ale_linters/javascript/jshint.vim

@@ -70,14 +70,14 @@ function! ale_linters#javascript#jshint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('javascript', {
+call ale#linter#Define('javascript', {
 \   'name': 'jshint',
 \   'executable': g:ale_javascript_jshint_executable,
 \   'command_callback': 'ale_linters#javascript#jshint#GetCommand',
 \   'callback': 'ale_linters#javascript#jshint#Handle',
 \})
 
-call ALEAddLinter('javascript.jsx', {
+call ale#linter#Define('javascript.jsx', {
 \   'name': 'jshint',
 \   'executable': g:ale_javascript_jshint_executable,
 \   'command_callback': 'ale_linters#javascript#jshint#GetCommand',

ale_linters/json/jsonlint.vim

@@ -35,7 +35,7 @@ function! ale_linters#json#jsonlint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('json', {
+call ale#linter#Define('json', {
 \   'name': 'jsonlint',
 \   'executable': 'jsonlint',
 \   'output_stream': 'stderr',

ale_linters/perl/perl.vim

@@ -37,7 +37,7 @@ function! ale_linters#perl#perl#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('perl', {
+call ale#linter#Define('perl', {
 \   'name': 'perl',
 \   'executable': 'perl',
 \   'output_stream': 'both',

ale_linters/perl/perlcritic.vim

@@ -37,7 +37,7 @@ function! ale_linters#perl#perlcritic#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('perl', {
+call ale#linter#Define('perl', {
 \   'name': 'perlcritic',
 \   'executable': 'perlcritic',
 \   'output_stream': 'sdtout',

ale_linters/php/php.vim

@@ -36,7 +36,7 @@ function! ale_linters#php#php#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('php', {
+call ale#linter#Define('php', {
 \   'name': 'php',
 \   'executable': 'php',
 \   'output_stream': 'both',

ale_linters/php/phpcs.vim

@@ -50,7 +50,7 @@ function! ale_linters#php#phpcs#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('php', {
+call ale#linter#Define('php', {
 \   'name': 'phpcs',
 \   'executable': 'phpcs',
 \   'command_callback': 'ale_linters#php#phpcs#GetCommand',

ale_linters/pug/puglint.vim

@@ -35,7 +35,7 @@ function! ale_linters#pug#puglint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('pug', {
+call ale#linter#Define('pug', {
 \   'name': 'puglint',
 \   'executable': 'pug-lint',
 \   'output_stream': 'stderr',

ale_linters/pyrex/cython.vim

@@ -34,7 +34,7 @@ function! ale_linters#pyrex#cython#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('pyrex', {
+call ale#linter#Define('pyrex', {
 \   'name': 'cython',
 \   'output_stream': 'stderr',
 \   'executable': 'cython',

ale_linters/python/flake8.vim

@@ -47,7 +47,7 @@ function! ale_linters#python#flake8#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('python', {
+call ale#linter#Define('python', {
 \   'name': 'flake8',
 \   'executable': 'flake8',
 \   'command': 'flake8 -',

ale_linters/ruby/rubocop.vim

@@ -40,7 +40,7 @@ function! ale_linters#ruby#rubocop#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('ruby', {
+call ale#linter#Define('ruby', {
 \   'name': 'rubocop',
 \   'executable': 'rubocop',
 \   'command': 'rubocop --format emacs --stdin _',

ale_linters/sass/sasslint.vim

@@ -6,7 +6,7 @@ endif
 
 let g:loaded_ale_linters_sass_sasslint = 1
 
-call ALEAddLinter('sass', {
+call ale#linter#Define('sass', {
 \   'name': 'sasslint',
 \   'executable': 'sass-lint',
 \   'command': g:ale#util#stdin_wrapper . ' .sass sass-lint -v -q -f compact',

ale_linters/scala/scalac.vim

@@ -49,7 +49,7 @@ function! ale_linters#scala#scalac#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('scala', {
+call ale#linter#Define('scala', {
 \   'name': 'scalac',
 \   'executable': 'scalac',
 \   'output_stream': 'stderr',

ale_linters/scss/sasslint.vim

@@ -6,7 +6,7 @@ endif
 
 let g:loaded_ale_linters_scss_sasslint = 1
 
-call ALEAddLinter('scss', {
+call ale#linter#Define('scss', {
 \   'name': 'sasslint',
 \   'executable': 'sass-lint',
 \   'command': g:ale#util#stdin_wrapper . ' .scss sass-lint -v -q -f compact',

ale_linters/scss/scsslint.vim

@@ -41,7 +41,7 @@ function! ale_linters#scss#scsslint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('scss', {
+call ale#linter#Define('scss', {
 \   'name': 'scsslint',
 \   'executable': 'scss-lint',
 \   'command': 'scss-lint --stdin-file-path=%s',

ale_linters/sh/shell.vim

@@ -74,7 +74,7 @@ function! ale_linters#sh#shell#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('sh', {
+call ale#linter#Define('sh', {
 \   'name': 'shell',
 \   'output_stream': 'stderr',
 \   'executable_callback': 'ale_linters#sh#shell#GetExecutable',

ale_linters/sh/shellcheck.vim

@@ -22,7 +22,7 @@ else
     let s:exclude_option = ''
 endif
 
-call ALEAddLinter('sh', {
+call ale#linter#Define('sh', {
 \   'name': 'shellcheck',
 \   'executable': 'shellcheck',
 \   'command': 'shellcheck ' . s:exclude_option . ' -f gcc -',

ale_linters/typescript/tslint.vim

@@ -43,7 +43,7 @@ function! ale_linters#typescript#tslint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('typescript', {
+call ale#linter#Define('typescript', {
 \   'name': 'tslint',
 \   'executable': 'tslint',
 \   'command': g:ale#util#stdin_wrapper . ' .ts tslint',

ale_linters/verilog/iverilog.vim

@@ -42,7 +42,7 @@ function! ale_linters#verilog#iverilog#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('verilog', {
+call ale#linter#Define('verilog', {
 \   'name': 'iverilog',
 \   'output_stream': 'stderr',
 \   'executable': 'iverilog',

ale_linters/verilog/verilator.vim

@@ -44,7 +44,7 @@ function! ale_linters#verilog#verilator#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('verilog', {
+call ale#linter#Define('verilog', {
 \   'name': 'verilator',
 \   'output_stream': 'stderr',
 \   'executable': 'verilator',

ale_linters/vim/vint.vim

@@ -9,7 +9,7 @@ let g:loaded_ale_linters_vim_vint = 1
 
 let s:format = '-f "{file_path}:{line_number}:{column_number}: {severity}: {description} (see {reference})'
 
-call ALEAddLinter('vim', {
+call ale#linter#Define('vim', {
 \   'name': 'vint',
 \   'executable': 'vint',
 \   'command': g:ale#util#stdin_wrapper . ' .vim vint -w --no-color ' . s:format,

ale_linters/yaml/yamllint.vim

@@ -40,7 +40,7 @@ function! ale_linters#yaml#yamllint#Handle(buffer, lines)
     return output
 endfunction
 
-call ALEAddLinter('yaml', {
+call ale#linter#Define('yaml', {
 \   'name': 'yamllint',
 \   'executable': 'yamllint',
 \   'command': g:ale#util#stdin_wrapper . ' .yml yamllint -f parsable',

autoload/ale.vim

@@ -0,0 +1,48 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Primary code path for the plugin
+"   Manages execution of linters when requested by autocommands
+
+let s:lint_timer = -1
+
+function! ale#Queue(delay) abort
+    if s:lint_timer != -1
+        call timer_stop(s:lint_timer)
+        let s:lint_timer = -1
+    endif
+
+    let linters = ale#linter#Get(&filetype)
+    if len(linters) == 0
+        " There are no linters to lint with, so stop here.
+        return
+    endif
+
+    if a:delay > 0
+        let s:lint_timer = timer_start(a:delay, function('ale#Lint'))
+    else
+        call ale#Lint()
+    endif
+endfunction
+
+function! ale#Lint(...) abort
+    let buffer = bufnr('%')
+    let linters = ale#linter#Get(&filetype)
+
+    " Set a variable telling us to clear the loclist later.
+    let g:ale_buffer_should_reset_map[buffer] = 1
+
+    for linter in linters
+        " Check if a given linter has a program which can be executed.
+        if has_key(linter, 'executable_callback')
+            let l:executable = ale#util#GetFunction(linter.executable_callback)(buffer)
+        else
+            let l:executable = linter.executable
+        endif
+
+        if !executable(l:executable)
+            " The linter's program cannot be executed, so skip it.
+            continue
+        endif
+
+        call ale#engine#Invoke(buffer, linter)
+    endfor
+endfunction

autoload/ale/cleanup.vim

@@ -0,0 +1,16 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Utility functions related to cleaning state.
+
+function! ale#cleanup#Buffer(buffer) abort
+    if has_key(g:ale_buffer_should_reset_map, a:buffer)
+        call remove(g:ale_buffer_should_reset_map, a:buffer)
+    endif
+
+    if has_key(g:ale_buffer_loclist_map, a:buffer)
+        call remove(g:ale_buffer_loclist_map, a:buffer)
+    endif
+
+    if has_key(g:ale_buffer_sign_dummy_map, a:buffer)
+        call remove(g:ale_buffer_sign_dummy_map, a:buffer)
+    endif
+endfunction

autoload/ale/cursor.vim

@@ -1,12 +1,6 @@
 " Author: w0rp <devw0rp@gmail.com>
 " Description: Echoes lint message for the current line, if any
 
-if exists('g:loaded_ale_cursor')
-    finish
-endif
-
-let g:loaded_ale_cursor = 1
-
 " Return a formatted message according to g:ale_echo_msg_format variable
 function! s:GetMessage(linter, type, text) abort
     let msg = g:ale_echo_msg_format
@@ -26,7 +20,7 @@ endfunction
 
 " This function will perform a binary search to find a message from the
 " loclist to echo when the cursor moves.
-function! s:BinarySearch(loclist, line, column)
+function! s:BinarySearch(loclist, line, column) abort
     let min = 0
     let max = len(a:loclist) - 1
     let last_column_match = -1
@@ -59,7 +53,7 @@ function! s:BinarySearch(loclist, line, column)
     endwhile
 endfunction
 
-function! ale#cursor#TruncatedEcho(message)
+function! ale#cursor#TruncatedEcho(message) abort
     let message = a:message
     " Change tabs to spaces.
     let message = substitute(message, "\t", ' ', 'g')
@@ -79,7 +73,7 @@ function! ale#cursor#TruncatedEcho(message)
     endtry
 endfunction
 
-function! ale#cursor#EchoCursorWarning(...)
+function! ale#cursor#EchoCursorWarning(...) abort
     " Only echo the warnings in normal mode, otherwise we will get problems.
     if mode() !=# 'n'
         return
@@ -108,7 +102,7 @@ endfunction
 
 let s:cursor_timer = -1
 
-function! ale#cursor#EchoCursorWarningWithDelay()
+function! ale#cursor#EchoCursorWarningWithDelay() abort
     if s:cursor_timer != -1
         call timer_stop(s:cursor_timer)
         let s:cursor_timer = -1

autoload/ale/engine.vim

@@ -1,19 +1,6 @@
 " Author: w0rp <devw0rp@gmail.com>
-" Description: Main entry point for this plugin
+" Description: Backend execution and job management
-"   Loads linters and manages lint jobs
+"   Executes linters in the background, using NeoVim or Vim 8 jobs
-
-if exists('g:loaded_ale_zmain')
-    finish
-endif
-
-let g:loaded_ale_zmain = 1
-
-let s:lint_timer = -1
-let s:linters = {}
-
-if !exists('g:ale_linters')
-    let g:ale_linters = {}
-endif
 
 " Stores information for each job including:
 "
@@ -22,20 +9,18 @@ endif
 " output: The array of lines for the output of the job.
 let s:job_info_map = {}
 
-" Globals which each part of the plugin should use.
+function! s:GetJobID(job) abort
-let g:ale_buffer_loclist_map = {}
+    if has('nvim')
-let g:ale_buffer_should_reset_map = {}
+        "In NeoVim, job values are just IDs.
-let g:ale_buffer_sign_dummy_map = {}
+        return a:job
-
-function! s:GetFunction(string_or_ref)
-    if type(a:string_or_ref) == type('')
-        return function(a:string_or_ref)
     endif
 
-    return a:string_or_ref
+    " In Vim 8, the job is a special variable, and we open a channel for each
+    " job. We'll use the ID of the channel instead as the job ID.
+    return ch_info(job_getchannel(a:job)).id
 endfunction
 
-function! s:ClearJob(job)
+function! s:ClearJob(job) abort
     let job_id = s:GetJobID(a:job)
     let linter = s:job_info_map[job_id].linter
 
@@ -55,7 +40,7 @@ function! s:ClearJob(job)
     call remove(linter, 'job')
 endfunction
 
-function! s:GatherOutput(job, data)
+function! s:GatherOutput(job, data) abort
     let job_id = s:GetJobID(a:job)
 
     if !has_key(s:job_info_map, job_id)
@@ -65,51 +50,15 @@ function! s:GatherOutput(job, data)
     call extend(s:job_info_map[job_id].output, a:data)
 endfunction
 
-function! s:GatherOutputNeoVim(job, data, event)
+function! s:GatherOutputVim(channel, data) abort
-    call s:GatherOutput(a:job, a:data)
-endfunction
-
-function! s:GatherOutputVim(channel, data)
     call s:GatherOutput(ch_getjob(a:channel), [a:data])
 endfunction
 
-function! s:LocItemCompare(left, right)
+function! s:GatherOutputNeoVim(job, data, event) abort
-    if a:left['lnum'] < a:right['lnum']
+    call s:GatherOutput(a:job, a:data)
-        return -1
-    endif
-
-    if a:left['lnum'] > a:right['lnum']
-        return 1
-    endif
-
-    if a:left['col'] < a:right['col']
-        return -1
-    endif
-
-    if a:left['col'] > a:right['col']
-        return 1
-    endif
-
-    return 0
 endfunction
 
-function! s:FixLoclist(buffer, loclist)
+function! s:HandleExit(job) abort
-    " Some errors have line numbers beyond the end of the file,
-    " so we need to adjust them so they set the error at the last line
-    " of the file instead.
-    let last_line_number = ale#util#GetLineCount(a:buffer)
-
-    for item in a:loclist
-        if item.lnum == 0
-            " When errors appear at line 0, put them at line 1 instead.
-            let item.lnum = 1
-        elseif item.lnum > last_line_number
-            let item.lnum = last_line_number
-        endif
-    endfor
-endfunction
-
-function! s:HandleExit(job)
     if a:job ==# 'no process'
         " Stop right away when the job is not valid in Vim 8.
         return
@@ -129,15 +78,10 @@ function! s:HandleExit(job)
     let output = job_info.output
     let buffer = job_info.buffer
 
-    let linter_loclist = s:GetFunction(linter.callback)(buffer, output)
+    let linter_loclist = ale#util#GetFunction(linter.callback)(buffer, output)
 
     " Make some adjustments to the loclists to fix common problems.
-    call s:FixLoclist(buffer, linter_loclist)
+    call s:FixLocList(buffer, linter_loclist)
-
-    " Remember which linter returned these items for later use.
-    for obj in linter_loclist
-        let obj.linter_name = linter.name
-    endfor
 
     if g:ale_buffer_should_reset_map[buffer]
         let g:ale_buffer_should_reset_map[buffer] = 0
@@ -150,7 +94,7 @@ function! s:HandleExit(job)
     " Sort the loclist again.
     " We need a sorted list so we can run a binary search against it
     " for efficient lookup of the messages in the cursor handler.
-    call sort(g:ale_buffer_loclist_map[buffer], 's:LocItemCompare')
+    call sort(g:ale_buffer_loclist_map[buffer], 'ale#util#LocItemCompare')
 
     if g:ale_set_loclist
         call setloclist(0, g:ale_buffer_loclist_map[buffer])
@@ -164,26 +108,31 @@ function! s:HandleExit(job)
     " matchadd('ALEError', '\%200l\%17v')
 endfunction
 
-function! s:GetJobID(job)
+function! s:HandleExitNeoVim(job, data, event) abort
-    if has('nvim')
-        "In NeoVim, job values are just IDs.
-        return a:job
-    endif
-
-    " In Vim 8, the job is a special variable, and we open a channel for each
-    " job. We'll use the ID of the channel instead as the job ID.
-    return ch_info(job_getchannel(a:job)).id
-endfunction
-
-function! s:HandleExitNeoVim(job, data, event)
     call s:HandleExit(a:job)
 endfunction
 
-function! s:HandleExitVim(channel)
+function! s:HandleExitVim(channel) abort
     call s:HandleExit(ch_getjob(a:channel))
 endfunction
 
-function! s:ApplyLinter(buffer, linter)
+function! s:FixLocList(buffer, loclist) abort
+    " Some errors have line numbers beyond the end of the file,
+    " so we need to adjust them so they set the error at the last line
+    " of the file instead.
+    let last_line_number = ale#util#GetLineCount(a:buffer)
+
+    for item in a:loclist
+        if item.lnum == 0
+            " When errors appear at line 0, put them at line 1 instead.
+            let item.lnum = 1
+        elseif item.lnum > last_line_number
+            let item.lnum = last_line_number
+        endif
+    endfor
+endfunction
+
+function! ale#engine#Invoke(buffer, linter) abort
     if has_key(a:linter, 'job')
         " Stop previous jobs for the same linter.
         call s:ClearJob(a:linter.job)
@@ -191,7 +140,7 @@ function! s:ApplyLinter(buffer, linter)
 
     if has_key(a:linter, 'command_callback')
         " If there is a callback for generating a command, call that instead.
-        let command = s:GetFunction(a:linter.command_callback)(a:buffer)
+        let command = ale#util#GetFunction(a:linter.command_callback)(a:buffer)
     else
         let command = a:linter.command
     endif
@@ -274,8 +223,7 @@ function! s:ApplyLinter(buffer, linter)
             call jobsend(job, input)
             call jobclose(job, 'stdin')
         elseif has('win32')
-            " On Windows, we have to send the buffer lines ourselves,
+            " On some Vim versions, we have to send the buffer data ourselves.
-            " as there are issues with Windows and 'in_buf'
             let input = join(getbufline(a:buffer, 1, '$'), "\n") . "\n"
             let channel = job_getchannel(job)
 
@@ -286,152 +234,3 @@ function! s:ApplyLinter(buffer, linter)
         endif
     endif
 endfunction
-
-function! s:TimerHandler(...)
-    let filetype = &filetype
-    let linters = ALEGetLinters(filetype)
-
-    let buffer = bufnr('%')
-
-    " Set a variable telling us to clear the loclist later.
-    let g:ale_buffer_should_reset_map[buffer] = 1
-
-    for linter in linters
-        " Check if a given linter has a program which can be executed.
-        if has_key(linter, 'executable_callback')
-            let l:executable = s:GetFunction(linter.executable_callback)(buffer)
-        else
-            let l:executable = linter.executable
-        endif
-
-        if !executable(l:executable)
-            " The linter's program cannot be executed, so skip it.
-            continue
-        endif
-
-        call s:ApplyLinter(buffer, linter)
-    endfor
-endfunction
-
-function s:BufferCleanup(buffer)
-    if has_key(g:ale_buffer_should_reset_map, a:buffer)
-        call remove(g:ale_buffer_should_reset_map, a:buffer)
-    endif
-
-    if has_key(g:ale_buffer_loclist_map, a:buffer)
-        call remove(g:ale_buffer_loclist_map, a:buffer)
-    endif
-
-    if has_key(g:ale_buffer_sign_dummy_map, a:buffer)
-        call remove(g:ale_buffer_sign_dummy_map, a:buffer)
-    endif
-endfunction
-
-function! ALEAddLinter(filetype, linter)
-    if !has_key(s:linters, a:filetype)
-        let s:linters[a:filetype] = []
-    endif
-
-    let new_linter = {
-    \   'name': a:linter.name,
-    \   'callback': a:linter.callback,
-    \}
-
-    if has_key(a:linter, 'executable_callback')
-        let new_linter.executable_callback = a:linter.executable_callback
-    else
-        let new_linter.executable = a:linter.executable
-    endif
-
-    if has_key(a:linter, 'command_callback')
-        let new_linter.command_callback = a:linter.command_callback
-    else
-        let new_linter.command = a:linter.command
-    endif
-
-    if has_key(a:linter, 'output_stream')
-        let new_linter.output_stream = a:linter.output_stream
-    else
-        let new_linter.output_stream = 'stdout'
-    endif
-
-    " TODO: Assert the value of the output_stream to be something sensible.
-
-    call add(s:linters[a:filetype], new_linter)
-endfunction
-
-function! ALEGetLinters(filetype)
-    if !has_key(s:linters, a:filetype)
-        return []
-    endif
-
-    if has_key(g:ale_linters, a:filetype)
-        let linters = []
-        " Filter loaded linters according to list of linters specified in option
-        for linter in s:linters[a:filetype]
-            if index(g:ale_linters[a:filetype], linter.name) != -1
-                call add(linters, linter)
-            endif
-        endfor
-        return linters
-    endif
-
-    return s:linters[a:filetype]
-endfunction
-
-function! ALELint(delay)
-    let filetype = &filetype
-    let linters = ALEGetLinters(filetype)
-
-    if s:lint_timer != -1
-        call timer_stop(s:lint_timer)
-        let s:lint_timer = -1
-    endif
-
-    if len(linters) == 0
-        " There are no linters to lint with, so stop here.
-        return
-    endif
-
-    if a:delay > 0
-        let s:lint_timer = timer_start(a:delay, function('s:TimerHandler'))
-    else
-        call s:TimerHandler()
-    endif
-endfunction
-
-" Load all of the linters for each filetype.
-runtime! ale_linters/*/*.vim
-
-if !g:ale_has_required_features
-    echoerr 'ALE requires NeoVim >= 0.1.5 or Vim 8 with +timers +job +channel'
-    echoerr 'Please update your editor appropriately.'
-    finish
-endif
-
-if g:ale_lint_on_text_changed
-    augroup ALERunOnTextChangedGroup
-        autocmd!
-        autocmd TextChanged,TextChangedI * call ALELint(g:ale_lint_delay)
-    augroup END
-endif
-
-if g:ale_lint_on_enter
-    augroup ALERunOnEnterGroup
-        autocmd!
-        autocmd BufEnter,BufRead * call ALELint(100)
-    augroup END
-endif
-
-if g:ale_lint_on_save
-    augroup ALERunOnSaveGroup
-        autocmd!
-        autocmd BufWrite * call ALELint(0)
-    augroup END
-endif
-
-" Clean up buffers automatically when they are unloaded.
-augroup ALEBuffferCleanup
-    autocmd!
-    autocmd BufUnload * call s:BufferCleanup('<abuf>')
-augroup END

autoload/ale/handlers.vim

@@ -4,13 +4,7 @@ scriptencoding utf-8
 "   linter which outputs warnings and errors in a format accepted by one of
 "   these functions can simply use one of these pre-defined error handlers.
 
-if exists('g:loaded_ale_handlers')
+function! ale#handlers#HandleGCCFormat(buffer, lines) abort
-    finish
-endif
-
-let g:loaded_ale_handlers = 1
-
-function! ale#handlers#HandleGCCFormat(buffer, lines)
     " Look for lines like the following.
     "
     " <stdin>:8:5: warning: conversion lacks type at end of format [-Wformat=]
@@ -40,7 +34,7 @@ function! ale#handlers#HandleGCCFormat(buffer, lines)
     return output
 endfunction
 
-function! ale#handlers#HandleCSSLintFormat(buffer, lines)
+function! ale#handlers#HandleCSSLintFormat(buffer, lines) abort
     " Matches patterns line the following:
     "
     " something.css: line 2, col 1, Error - Expected RBRACE at line 2, col 1. (errors)

autoload/ale/linter.vim

@@ -0,0 +1,66 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Linter registration and lazy-loading
+"   Retrieves linters as requested by the engine, loading them if needed.
+
+let s:linters = {}
+
+function! ale#linter#Define(filetype, linter) abort
+    if !has_key(s:linters, a:filetype)
+        let s:linters[a:filetype] = []
+    endif
+
+    let new_linter = {
+    \   'name': a:linter.name,
+    \   'callback': a:linter.callback,
+    \}
+
+    if has_key(a:linter, 'executable_callback')
+        let new_linter.executable_callback = a:linter.executable_callback
+    else
+        let new_linter.executable = a:linter.executable
+    endif
+
+    if has_key(a:linter, 'command_callback')
+        let new_linter.command_callback = a:linter.command_callback
+    else
+        let new_linter.command = a:linter.command
+    endif
+
+    if has_key(a:linter, 'output_stream')
+        let new_linter.output_stream = a:linter.output_stream
+    else
+        let new_linter.output_stream = 'stdout'
+    endif
+
+    " TODO: Assert the value of the output_stream to be something sensible.
+
+    call add(s:linters[a:filetype], new_linter)
+endfunction
+
+function! ale#linter#Get(filetype) abort
+    if a:filetype ==# ''
+        " Empty filetype? Nothing to be done about that.
+        return []
+    endif
+
+    if has_key(s:linters, a:filetype)
+        " We already loaded a linter, great!
+        return s:linters[a:filetype]
+    endif
+
+    if has_key(g:ale_linters, a:filetype)
+        " Filter loaded linters according to list of linters specified in option.
+        for linter in g:ale_linters[a:filetype]
+            execute 'runtime! ale_linters/' . a:filetype . '/' . linter . '.vim'
+        endfor
+    else
+        execute 'runtime! ale_linters/' . a:filetype . '/*.vim'
+    endif
+
+    if !has_key(s:linters, a:filetype)
+        " If we couldn't load any linters, let everyone know.
+        let s:linters[a:filetype] = []
+    endif
+
+    return s:linters[a:filetype]
+endfunction

autoload/ale/sign.vim

@@ -1,12 +1,7 @@
-scriptencoding utf-8
+scriptencoding utf8
 " Author: w0rp <devw0rp@gmail.com>
 " Description: Draws error and warning signs into signcolumn
 
-if exists('g:loaded_ale_sign')
-    finish
-endif
-
-let g:loaded_ale_sign = 1
 let b:dummy_sign_set_map = {}
 
 if !hlexists('ALEErrorSign')
@@ -40,7 +35,7 @@ execute 'sign define ALEWarningSign text=' . g:ale_sign_warning
 \   . ' texthl=ALEWarningSign'
 sign define ALEDummySign
 
-function! ale#sign#FindCurrentSigns(buffer)
+function! ale#sign#FindCurrentSigns(buffer) abort
     " Matches output like :
     " line=4  id=1  name=ALEErrorSign
     " строка=1  id=1000001  имя=ALEErrorSign
@@ -66,7 +61,7 @@ endfunction
 " Given a loclist, combine the loclist into a list of signs such that only
 " one sign appears per line. Error lines will take precedence.
 " The loclist will have been previously sorted.
-function! ale#sign#CombineSigns(loclist)
+function! ale#sign#CombineSigns(loclist) abort
     let signlist = []
 
     for obj in a:loclist
@@ -98,7 +93,7 @@ function! ale#sign#CombineSigns(loclist)
 endfunction
 
 " This function will set the signs which show up on the left.
-function! ale#sign#SetSigns(buffer, loclist)
+function! ale#sign#SetSigns(buffer, loclist) abort
     let signlist = ale#sign#CombineSigns(a:loclist)
 
     if len(signlist) > 0 || g:ale_sign_column_always

autoload/ale/statusline.vim

@@ -1,7 +1,7 @@
 " Author: KabbAmine <amine.kabb@gmail.com>
 " Description: Statusline related function(s)
 
-function! ALEGetStatusLine() abort
+function! ale#statusline#Status() abort
     " Returns a formatted string that can be integrated in the
     " statusline
 

autoload/ale/util.vim

@@ -1,13 +1,7 @@
 " Author: w0rp <devw0rp@gmail.com>
 " Description: Contains miscellaneous functions
 
-if exists('g:loaded_ale_util')
+function! s:FindWrapperScript() abort
-    finish
-endif
-
-let g:loaded_ale_util = 1
-
-function! s:FindWrapperScript()
     for parent in split(&runtimepath, ',')
         " Expand the path to deal with ~ issues.
         let path = expand(parent . '/' . 'stdin-wrapper')
@@ -24,20 +18,48 @@ endfunction
 
 let g:ale#util#stdin_wrapper = s:FindWrapperScript()
 
-" Return the number of lines for a given buffer.
-function! ale#util#GetLineCount(buffer)
-    return len(getbufline(a:buffer, 1, '$'))
-endfunction
-
-" Given a buffer and a filename, find the nearest file by searching upwards
-" through the paths relative to the given buffer.
-function! ale#util#FindNearestFile(buffer, filename)
-    return findfile(a:filename, fnamemodify(bufname(a:buffer), ':p') . ';')
-endfunction
-
 " A null file for sending output to nothing.
 let g:ale#util#nul_file = '/dev/null'
 
 if has('win32')
     let g:ale#util#nul_file = 'nul'
 endif
+
+" Return the number of lines for a given buffer.
+function! ale#util#GetLineCount(buffer) abort
+    return len(getbufline(a:buffer, 1, '$'))
+endfunction
+
+" Given a buffer and a filename, find the nearest file by searching upwards
+" through the paths relative to the given buffer.
+function! ale#util#FindNearestFile(buffer, filename) abort
+    return findfile(a:filename, fnamemodify(bufname(a:buffer), ':p') . ';')
+endfunction
+
+function! ale#util#GetFunction(string_or_ref) abort
+    if type(a:string_or_ref) == type('')
+        return function(a:string_or_ref)
+    endif
+
+    return a:string_or_ref
+endfunction
+
+function! ale#util#LocItemCompare(left, right) abort
+    if a:left['lnum'] < a:right['lnum']
+        return -1
+    endif
+
+    if a:left['lnum'] > a:right['lnum']
+        return 1
+    endif
+
+    if a:left['col'] < a:right['col']
+        return -1
+    endif
+
+    if a:left['col'] > a:right['col']
+        return 1
+    endif
+
+    return 0
+endfunction

doc/ale.txt

@@ -289,11 +289,30 @@ g:ale_statusline_format                               *g:ale_statusline_format*
   Type: |List|
   Default: `['%d error(s)', '%d warning(s)', 'OK']`
 
-  This variable defines the format of |`ALEGetStatusLine()`| output.
+  This variable defines the format of |`ale#statusline#status()`| output.
   - The 1st element is for errors
   - The 2nd element is for warnings
   - The 3rd element is for when no errors are detected
 
+g:airline#extensions#ale#enabled             *g:airline#extensions#ale#enabled*
+
+  Type: |Number|
+  Default: `1`
+
+  Enables or disables the |airline|'s native extension for ale, which displays
+  warnings and errors in the status line, prefixed by
+  |airline#extensions#ale#error_symbol| and
+  |airline#extensions#ale#warning_symbol|.
+
+g:airline#extensions#ale#enabled             *g:airline#extensions#ale#enabled*
+
+  Type: |Number|
+  Default: `1`
+
+  Enables or disables the |airline|'s native extension for ale, which displays
+  warnings and errors in the status line, prefixed by
+  |airline#extensions#ale#error_symbol| and
+  |airline#extensions#ale#warning_symbol|.
 
 ===============================================================================
 4. Linter Specific Options                                 *ale-linter-options*
@@ -413,14 +432,14 @@ g:ale_javascript_jshint_executable         *g:ale_javascript_jshint_executable*
 ===============================================================================
 5. API                                                                *ale-api*
 
-ALELint(delay)                                                      *ALELint()*
+ale#Queue(delay)                                                  *ale#Queue()*
   Run linters for the current buffer, based on the filetype of the buffer,
   with a given `delay`. A `delay` of `0` will run the linters immediately.
   The linters will always be run in the background. Calling this function
   again from the same buffer
 
 
-ALEAddLinter(filetype, linter)                                 *ALEAddLinter()*
+ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
   Given a |String| for a filetype and a |Dictionary| Describing a linter
   configuration, add a linter for the given filetype. The dictionaries each
   offer the following options:
@@ -492,21 +511,21 @@ ALEAddLinter(filetype, linter)                                 *ALEAddLinter()*
   'command': g:ale#util#stdin_wrapper . ' .hs ghc -fno-code -v0',
 <
 
-ALEGetLinters(filetype)                                       *ALEGetLinters()*
+ale#linter#Get(filetype)                                     *ale#linter#Get()*
   Return all of linters configured for a given filetype as a |List| of
-  |Dictionary| values in the format specified by |ALEAddLinter()|.
+  |Dictionary| values in the format specified by |ale#linter#Define()|.
 
 
-ALEGetStatusLine()                                         *ALEGetStatusLine()*
+ale#statusline#Status()                               *ale#statusline#Status()*
   Return a formatted string that can be added to the statusline.
   The output's format is defined in |`g:ale_statusline_format`|.
   To enable it, the following should be present in your |statusline| settings: >
-  %{ALEGetStatusLine()}
+  %{ale#statusline#status()}
 
 
 g:ale#util#stdin_wrapper                             *g:ale#util#stdin_wrapper*
   This variable names a wrapper script for sending stdin input to programs
-  which cannot accept input via stdin. See |ALEAddLinter| for more.
+  which cannot accept input via stdin. See |ale#linter#Define()| for more.
 
 
 ===============================================================================

plugin/ale.vim

@@ -1,12 +1,11 @@
 " Author: w0rp <devw0rp@gmail.com>
-" Description: This file sets up configuration settings for the ALE plugin.
+" Description: Main entry point for the plugin: sets up prefs and autocommands
-"   Flags can be set in vimrc files and so on to disable particular features
+"   Preferences can be set in vimrc files and so on to configure ale
 
-if exists('g:loaded_ale_flags')
+if exists('g:loaded_ale')
     finish
 endif
-
+let g:loaded_ale = 1
-let g:loaded_ale_flags = 1
 
 " A flag for detecting if the required features are set.
 if has('nvim')
@@ -15,6 +14,15 @@ else
     let g:ale_has_required_features = has('timers') && has('job') && has('channel')
 endif
 
+if !g:ale_has_required_features
+    echoerr 'ALE requires NeoVim >= 0.1.5 or Vim 8 with +timers +job +channel'
+    echoerr 'Please update your editor appropriately.'
+    finish
+endif
+
+" This list configures which linters are enabled for which languages.
+let g:ale_linters = get(g:, 'ale_linters', {})
+
 " This flag can be set to 0 to disable linting when text is changed.
 let g:ale_lint_on_text_changed = get(g:, 'ale_lint_on_text_changed', 1)
 
@@ -64,3 +72,43 @@ let g:ale_echo_msg_format = get(g:, 'ale_echo_msg_format', '%s')
 " Strings used for severity in the echoed message
 let g:ale_echo_msg_error_str = get(g:, 'ale_echo_msg_error_str', 'Error')
 let g:ale_echo_msg_warning_str = get(g:, 'ale_echo_msg_warning_str', 'Warning')
+
+if g:ale_lint_on_text_changed
+    augroup ALERunOnTextChangedGroup
+        autocmd!
+        autocmd TextChanged,TextChangedI * call ale#Queue(g:ale_lint_delay)
+    augroup END
+endif
+
+if g:ale_lint_on_enter
+    augroup ALERunOnEnterGroup
+        autocmd!
+        autocmd BufEnter,BufRead * call ale#Queue(100)
+    augroup END
+endif
+
+if g:ale_lint_on_save
+    augroup ALERunOnSaveGroup
+        autocmd!
+        autocmd BufWrite * call ale#Queue(0)
+    augroup END
+endif
+
+" Clean up buffers automatically when they are unloaded.
+augroup ALEBufferCleanup
+    autocmd!
+    autocmd BufUnload * call ale#cleanup#Buffer('<abuf>')
+augroup END
+
+" Globals which each part of the plugin should use.
+let g:ale_buffer_loclist_map = {}
+let g:ale_buffer_should_reset_map = {}
+let g:ale_buffer_sign_dummy_map = {}
+
+" Backwards compatibility
+function! ALELint(delay)
+    call ale#Queue(a:delay)
+endfunction
+function! ALEGetStatusLine()
+    call ale#statusline#Status()
+endfunction