Add support for filling holes using ghc-mod's auto command

README.md

@@ -79,6 +79,7 @@ You can edit Atom keybindings by opening 'Edit → Open Your Keymap'. Here is a
   'ctrl-alt-i': 'haskell-ghc-mod:show-info' #this is an example binding
   'ctrl-alt-T': 'haskell-ghc-mod:insert-type' #this is an example binding
   '': 'haskell-ghc-mod:case-split'
+  '': 'haskell-ghc-mod:hole-fill'
   '': 'haskell-ghc-mod:sig-fill'
   '': 'haskell-ghc-mod:show-info-fallback-to-type'
   '': 'haskell-ghc-mod:show-type-fallback-to-info'

lib/ghc-mod/ghc-modi-process.coffee

@@ -340,6 +340,27 @@ class GhcModiProcess
           ]
         replacement: text
 
+  doHoleFill: (buffer, crange) =>
+    return Promise.resolve [] unless buffer.getUri()?
+    crange = Util.tabShiftForRange(buffer, crange)
+    @queueCmd 'typeinfo',
+      interactive: @caps?.interactiveCaseSplit ? false
+      buffer: buffer
+      command: 'auto',
+      uri: buffer.getUri()
+      text: buffer.getText() if buffer.isModified()
+      args: [crange.start.row + 1, crange.start.column + 1]
+    .then (lines) ->
+      return null if lines.length == 0 or lines[1] == ""
+
+      [line_, rowstart, colstart, rowend, colend, text] = lines[0].match(/^(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)
+
+      range: Range.fromObject [
+        [parseInt(rowstart) - 1, parseInt(colstart) - 1],
+        [parseInt(rowend) - 1, parseInt(colend) - 1]
+      ]
+      suggestions: lines[1..]
+
   doSigFill: (buffer, crange) =>
     return Promise.resolve [] unless buffer.getUri()?
     crange = Util.tabShiftForRange(buffer, crange)

lib/upi-consumer.coffee

@@ -1,5 +1,6 @@
 {CompositeDisposable} = require 'atom'
 ImportListView = require './views/import-list-view'
+SuggestionListView = require './views/suggestion-list-view'
 
 module.exports =
 class UPIConsumer
@@ -24,6 +25,7 @@ class UPIConsumer
     'haskell-ghc-mod:show-type': @tooltipCommand @typeTooltip
     'haskell-ghc-mod:show-info': @tooltipCommand @infoTooltip
     'haskell-ghc-mod:case-split': @caseSplitCommand
+    'haskell-ghc-mod:hole-fill': @holeFillCommand
     'haskell-ghc-mod:sig-fill': @sigFillCommand
     'haskell-ghc-mod:go-to-declaration': @goToDeclCommand
     'haskell-ghc-mod:show-info-fallback-to-type': @tooltipCommand @infoTypeTooltip
@@ -40,6 +42,7 @@ class UPIConsumer
         {label: 'Show Info', command: 'haskell-ghc-mod:show-info'}
         {label: 'Show Type And Info', command: 'haskell-ghc-mod:show-type-and-info'}
         {label: 'Case Split', command: 'haskell-ghc-mod:case-split'}
+        {label: 'Hole Fill', command: 'haskell-ghc-mod:hole-fill'}
         {label: 'Sig Fill', command: 'haskell-ghc-mod:sig-fill'}
         {label: 'Insert Type', command: 'haskell-ghc-mod:insert-type'}
         {label: 'Insert Import', command: 'haskell-ghc-mod:insert-import'}
@@ -146,6 +149,23 @@ class UPIConsumer
         res.forEach ({range, replacement}) ->
           editor.setTextInBufferRange(range, replacement)
 
+  holeFillCommand: ({target, detail}) =>
+    editor = target.getModel()
+    @upi.withEventRange {editor, detail}, ({crange}) =>
+      @process.doHoleFill(editor.getBuffer(), crange)
+      .then (res) ->
+        return null unless res?
+
+        {range, suggestions} = res
+
+        if suggestions.length == 1
+          editor.setTextInBufferRange(range, suggestions[0])
+        else
+          new SuggestionListView
+            items: suggestions
+            onConfirmed: (suggestion) ->
+              editor.setTextInBufferRange(range, suggestion)
+
   sigFillCommand: ({target, detail}) =>
     editor = target.getModel()
     @upi.withEventRange {editor, detail}, ({crange}) =>

lib/views/suggestion-list-view.coffee

@@ -0,0 +1,30 @@
+{SelectListView} = require 'atom-space-pen-views'
+
+module.exports=
+class SuggestionListView extends SelectListView
+  initialize: ({@onConfirmed, items}) ->
+    super
+    @panel = atom.workspace.addModalPanel
+      item: this
+      visible: false
+    @addClass 'ide-haskell'
+    @show items
+
+  cancelled: ->
+    @panel.destroy()
+
+  getFilterKey: ->
+    "text"
+
+  show: (list) ->
+    @setItems list
+    @panel.show()
+    @storeFocusedElement()
+    @focusFilterEditor()
+
+  viewForItem: (mod) ->
+    "<li><pre>#{mod}</pre></li>"
+
+  confirmed: (mod) ->
+    @onConfirmed? mod
+    @cancel()