Detect and use CM files for smlnj (#884)

* Detect and use CM files for smlnj

* Split into two checkers

- one for CM projects
- one for single SML files

* Fix some typos

* Fix error caught by writing tests

We want to actually use `glob` to search in paths upwards from us.
(Previously we were just searching in the current directory every time!)

* Fix errors from former test run

* Write tests for GetCmFile and GetExecutableSmlnj

* Typo in 'smlnj/' fixture filenames

1 files changed, 87 insertions, 0 deletions

diff --git a/autoload/ale/handlers/sml.vim b/autoload/ale/handlers/sml.vim
new file mode 100644
index 00000000..822a2eff
--- /dev/null
+++ b/autoload/ale/handlers/sml.vim
@@ -0,0 +1,87 @@
+" Author: Jake Zimmerman <jake@zimmerman.io>
+" Description: Shared functions for SML linters
+
+function! ale#handlers#sml#GetCmFile(buffer) abort
+    let l:pattern = ale#Var(a:buffer, 'sml_smlnj_cm_file')
+    let l:as_list = 1
+
+    let l:cmfile = ''
+    for l:path in ale#path#Upwards(expand('#' . a:buffer . ':p:h'))
+        let l:results = glob(l:path . '/' . l:pattern, 0, l:as_list)
+        if len(l:results) > 0
+            " If there is more than one CM file, we take the first one
+            " See :help ale-sml-smlnj for how to configure this.
+            let l:cmfile = l:results[0]
+        endif
+    endfor
+
+    return l:cmfile
+endfunction
+
+" Only one of smlnj or smlnj-cm can be enabled at a time.
+" executable_callback is called before *every* lint attempt
+function! s:GetExecutable(buffer, source) abort
+    if ale#handlers#sml#GetCmFile(a:buffer) is# ''
+        " No CM file found; only allow single-file mode to be enabled
+        if a:source is# 'smlnj-file'
+            return 'sml'
+        elseif a:source is# 'smlnj-cm'
+            return ''
+        endif
+    else
+        " Found a CM file; only allow cm-file mode to be enabled
+        if a:source is# 'smlnj-file'
+            return ''
+        elseif a:source is# 'smlnj-cm'
+            return 'sml'
+        endif
+    endif
+endfunction
+
+function! ale#handlers#sml#GetExecutableSmlnjCm(buffer) abort
+    return s:GetExecutable(a:buffer, 'smlnj-cm')
+endfunction
+function! ale#handlers#sml#GetExecutableSmlnjFile(buffer) abort
+    return s:GetExecutable(a:buffer, 'smlnj-file')
+endfunction
+
+function! ale#handlers#sml#Handle(buffer, lines) abort
+    " Try to match basic sml errors
+    " TODO(jez) We can get better errorfmt strings from Syntastic
+
+    let l:out = []
+    let l:pattern = '^.*\:\([0-9\.]\+\)\ \(\w\+\)\:\ \(.*\)'
+    let l:pattern2 = '^.*\:\([0-9]\+\)\.\?\([0-9]\+\).* \(\(Warning\|Error\): .*\)'
+
+    for l:line in a:lines
+        let l:match2 = matchlist(l:line, l:pattern2)
+
+        if len(l:match2) != 0
+          call add(l:out, {
+          \   'bufnr': a:buffer,
+          \   'lnum': l:match2[1] + 0,
+          \   'col' : l:match2[2] - 1,
+          \   'text': l:match2[3],
+          \   'type': l:match2[3] =~# '^Warning' ? 'W' : 'E',
+          \})
+          continue
+        endif
+
+        let l:match = matchlist(l:line, l:pattern)
+
+        if len(l:match) != 0
+          call add(l:out, {
+          \   'bufnr': a:buffer,
+          \   'lnum': l:match[1] + 0,
+          \   'text': l:match[2] . ': ' . l:match[3],
+          \   'type': l:match[2] is# 'error' ? 'E' : 'W',
+          \})
+          continue
+        endif
+
+    endfor
+
+    return l:out
+endfunction
+
+" vim:ts=4:sts=4:sw=4