From 1fe6c498ac8692e433ac84d0a4d3250eea94e074 Mon Sep 17 00:00:00 2001
From: Andrew Stubbs <andrew.stubbs@gmail.com>
Date: Wed, 14 May 2014 13:30:18 +0100
Subject: [PATCH] Make hard tabs align to columns.

---
 src/token.coffee          | 30 +++++++++++++++++++-----------
 src/tokenized-line.coffee |  8 ++++++--
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/src/token.coffee b/src/token.coffee
index 5f1baab1d..d6cde6856 100644
--- a/src/token.coffee
+++ b/src/token.coffee
@@ -42,16 +42,19 @@ class Token
   whitespaceRegexForTabLength: (tabLength) ->
     WhitespaceRegexesByTabLength[tabLength] ?= new RegExp("([ ]{#{tabLength}})|(\t)|([^\t]+)", "g")
 
-  breakOutAtomicTokens: (tabLength, breakOutLeadingSoftTabs) ->
+  breakOutAtomicTokens: (tabLength, breakOutLeadingSoftTabs, startColumn) ->
     if @hasSurrogatePair
       outputTokens = []
+      column = startColumn
 
       for token in @breakOutSurrogatePairs()
+        nextColumn += token.value.length
         if token.isAtomic
           outputTokens.push(token)
         else
-          outputTokens.push(token.breakOutAtomicTokens(tabLength, breakOutLeadingSoftTabs)...)
+          outputTokens.push(token.breakOutAtomicTokens(tabLength, breakOutLeadingSoftTabs, column)...)
         breakOutLeadingSoftTabs = token.isOnlyWhitespace() if breakOutLeadingSoftTabs
+        column = nextColumn
 
       outputTokens
     else
@@ -64,17 +67,21 @@ class Token
 
       outputTokens = []
       regex = @whitespaceRegexForTabLength(tabLength)
+      column = startColumn
       while match = regex.exec(@value)
         [fullMatch, softTab, hardTab] = match
+        token = null
         if softTab and breakOutLeadingSoftTabs
-          outputTokens.push(@buildSoftTabToken(tabLength))
+          token = @buildSoftTabToken(tabLength)
         else if hardTab
           breakOutLeadingSoftTabs = false
-          outputTokens.push(@buildHardTabToken(tabLength))
+          token = @buildHardTabToken(tabLength, column)
         else
           breakOutLeadingSoftTabs = false
           value = match[0]
-          outputTokens.push(new Token({value, @scopes}))
+          token = new Token({value, @scopes})
+        column += token.value.length
+        outputTokens.push(token)
 
       outputTokens
 
@@ -105,17 +112,18 @@ class Token
       isAtomic: true
     )
 
-  buildHardTabToken: (tabLength) ->
-    @buildTabToken(tabLength, true)
+  buildHardTabToken: (tabLength, column) ->
+    @buildTabToken(tabLength, true, column)
 
   buildSoftTabToken: (tabLength) ->
-    @buildTabToken(tabLength, false)
+    @buildTabToken(tabLength, false, 0)
 
-  buildTabToken: (tabLength, isHardTab) ->
+  buildTabToken: (tabLength, isHardTab, column) ->
+    tabStop = tabLength - column % tabLength
     new Token(
-      value: _.multiplyString(" ", tabLength)
+      value: _.multiplyString(" ", tabStop)
       scopes: @scopes
-      bufferDelta: if isHardTab then 1 else tabLength
+      bufferDelta: if isHardTab then 1 else tabStop
       isAtomic: true
       isHardTab: isHardTab
     )
diff --git a/src/tokenized-line.coffee b/src/tokenized-line.coffee
index 1bbec7972..02a77c2e1 100644
--- a/src/tokenized-line.coffee
+++ b/src/tokenized-line.coffee
@@ -5,8 +5,8 @@ idCounter = 1
 module.exports =
 class TokenizedLine
   constructor: ({tokens, @lineEnding, @ruleStack, @startBufferColumn, @fold, @tabLength, @indentLevel}) ->
-    @tokens = @breakOutAtomicTokens(tokens)
     @startBufferColumn ?= 0
+    @tokens = @breakOutAtomicTokens(tokens)
     @text = _.pluck(@tokens, 'value').join('')
     @bufferDelta = _.sum(_.pluck(@tokens, 'bufferDelta'))
     @id = idCounter++
@@ -113,8 +113,12 @@ class TokenizedLine
   breakOutAtomicTokens: (inputTokens) ->
     outputTokens = []
     breakOutLeadingSoftTabs = true
+    column = @startBufferColumn
     for token in inputTokens
-      outputTokens.push(token.breakOutAtomicTokens(@tabLength, breakOutLeadingSoftTabs)...)
+      newTokens = token.breakOutAtomicTokens(@tabLength, breakOutLeadingSoftTabs, column)
+      for newToken in newTokens
+        column += newToken.value.length
+      outputTokens.push(newTokens...)
       breakOutLeadingSoftTabs = token.isOnlyWhitespace() if breakOutLeadingSoftTabs
     outputTokens