From 597bf15f6293fa672edf54f16156e70f7e23a784 Mon Sep 17 00:00:00 2001
From: Edward Faulkner <ef@alum.mit.edu>
Date: Mon, 25 May 2015 18:40:56 -0400
Subject: [PATCH] Respect syntax error offset location

---
 lib/compiler.js    |  2 +-
 lib/helpers.js     | 24 +++++++++++++++++++-----
 lib/optimiser.js   |  2 +-
 src/helpers.coffee | 20 ++++++++++++++++----
 4 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/lib/compiler.js b/lib/compiler.js
index d48a9454..7ddd3d90 100644
--- a/lib/compiler.js
+++ b/lib/compiler.js
@@ -652,7 +652,7 @@ exports.Compiler = function () {
   Compiler.compile = function (this$) {
     return function () {
       var cache$2;
-      return (cache$2 = new this$).compile.apply(cache$2, [].slice.call(arguments));
+      return (cache$2 = new this$()).compile.apply(cache$2, [].slice.call(arguments));
     };
   }(Compiler);
   defaultRules = [
diff --git a/lib/helpers.js b/lib/helpers.js
index 4471b06c..94c17a79 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -49,16 +49,30 @@ this.humanReadable = humanReadable = function (str) {
   return str.replace(/\uEFEF/g, '(INDENT)').replace(/\uEFFE/g, '(DEDENT)').replace(/\uEFFF/g, '(TERM)');
 };
 this.formatParserError = function (input, e) {
-  var found, message, realColumn, unicode;
-  realColumn = cleanMarkers(('' + input.split('\n')[e.line - 1] + '\n').slice(0, e.column)).length;
+  var column, found, line, lines, message, offset, realColumn, unicode;
+  lines = input.split('\n');
+  line = e.line - 1;
+  column = e.column;
+  offset = e.offset;
+  while (offset > 0) {
+    if (offset > lines[line].length) {
+      offset -= lines[line].length;
+      line += 1;
+    } else {
+      column += offset;
+      offset = 0;
+    }
+  }
+  realColumn = cleanMarkers(('' + lines[line] + '\n').slice(0, column)).length;
+  line += 1;
   if (!(null != e.found))
-    return 'Syntax error on line ' + e.line + ', column ' + realColumn + ': unexpected end of input';
+    return 'Syntax error on line ' + line + ', column ' + realColumn + ': unexpected end of input';
   found = JSON.stringify(humanReadable(e.found));
   found = found.replace(/^"|"$/g, '').replace(/'/g, "\\'").replace(/\\"/g, '"');
   unicode = e.found.charCodeAt(0).toString(16).toUpperCase();
   unicode = '\\u' + '0000'.slice(unicode.length) + unicode;
-  message = 'Syntax error on line ' + e.line + ', column ' + realColumn + ": unexpected '" + found + "' (" + unicode + ')';
-  return '' + message + '\n' + pointToErrorLocation(input, e.line, realColumn);
+  message = 'Syntax error on line ' + line + ', column ' + realColumn + ": unexpected '" + found + "' (" + unicode + ')';
+  return '' + message + '\n' + pointToErrorLocation(input, line, realColumn);
 };
 this.pointToErrorLocation = pointToErrorLocation = function (source, line, column, numLinesOfContext) {
   var currentLineOffset, lines, numberedLines, padSize, postLines, preLines, startLine;
diff --git a/lib/optimiser.js b/lib/optimiser.js
index 874585fa..c25cd58e 100644
--- a/lib/optimiser.js
+++ b/lib/optimiser.js
@@ -387,7 +387,7 @@ exports.Optimiser = function () {
   Optimiser.optimise = function (this$) {
     return function () {
       var cache$2;
-      return (cache$2 = new this$).optimise.apply(cache$2, [].slice.call(arguments));
+      return (cache$2 = new this$()).optimise.apply(cache$2, [].slice.call(arguments));
     };
   }(Optimiser);
   Optimiser.isTruthy = isTruthy;
diff --git a/src/helpers.coffee b/src/helpers.coffee
index 5498e9d4..26bdcc24 100644
--- a/src/helpers.coffee
+++ b/src/helpers.coffee
@@ -32,15 +32,27 @@ cleanMarkers = (str) -> str.replace /[\uEFEF\uEFFE\uEFFF]/g, ''
   ((str.replace /\uEFEF/g, '(INDENT)').replace /\uEFFE/g, '(DEDENT)').replace /\uEFFF/g, '(TERM)'
 
 @formatParserError = (input, e) ->
-  realColumn = (cleanMarkers "#{(input.split '\n')[e.line - 1]}\n"[...e.column]).length
+  lines = input.split('\n')
+  line = e.line - 1 # switch to zero-indexed
+  column = e.column
+  offset = e.offset
+  while offset > 0
+    if offset > lines[line].length
+      offset -= lines[line].length
+      line += 1
+    else
+      column += offset
+      offset = 0
+  realColumn = (cleanMarkers "#{lines[line]}\n"[...column]).length
+  line += 1 # switch back to one-indexed
   unless e.found?
-    return "Syntax error on line #{e.line}, column #{realColumn}: unexpected end of input"
+    return "Syntax error on line #{line}, column #{realColumn}: unexpected end of input"
   found = JSON.stringify humanReadable e.found
   found = ((found.replace /^"|"$/g, '').replace /'/g, '\\\'').replace /\\"/g, '"'
   unicode = ((e.found.charCodeAt 0).toString 16).toUpperCase()
   unicode = "\\u#{"0000"[unicode.length..]}#{unicode}"
-  message = "Syntax error on line #{e.line}, column #{realColumn}: unexpected '#{found}' (#{unicode})"
-  "#{message}\n#{pointToErrorLocation input, e.line, realColumn}"
+  message = "Syntax error on line #{line}, column #{realColumn}: unexpected '#{found}' (#{unicode})"
+  "#{message}\n#{pointToErrorLocation input, line, realColumn}"
 
 @pointToErrorLocation = pointToErrorLocation = (source, line, column, numLinesOfContext = 3) ->
   lines = source.split '\n'