diff --git a/lib/lexer.js b/lib/lexer.js
index 87fd371c..cb45c2cf 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -393,7 +393,7 @@
       }
       doc = doc.replace(/^\n/, '').replace(new RegExp("" + (options.quote), "g"), '\\$&');
       if (options.quote === "'") {
-        doc = this.oldline(doc, true);
+        doc = this.escapeLines(doc, true);
       }
       return doc;
     };
@@ -477,8 +477,10 @@
       return !i ? false : str.slice(0, i);
     };
     Lexer.prototype.interpolateString = function(str, options) {
-      var _len, _ref2, _ref3, end, escaped, expr, i, idx, inner, interpolated, lexer, nested, pi, push, quote, s, tag, tok, token, tokens, value;
-      options || (options = {});
+      var _len, _ref2, _ref3, end, escapeQuotes, escaped, expr, heredoc, i, idx, inner, interpolated, lexer, nested, pi, push, quote, s, tag, tok, token, tokens, value;
+      _ref2 = options || {};
+      heredoc = _ref2.heredoc;
+      escapeQuotes = _ref2.escapeQuotes;
       quote = str.charAt(0);
       if (quote !== '"' || str.length < 3) {
         return this.token('STRING', str);
@@ -492,12 +494,12 @@
           i += 1;
         } else if (expr = this.balancedString(str.slice(i), [['#{', '}']])) {
           if (pi < i) {
-            s = quote + this.oldline(str.slice(pi, i), options.heredoc) + quote;
+            s = quote + this.escapeLines(str.slice(pi, i), heredoc) + quote;
             tokens.push(['STRING', s]);
           }
-          inner = expr.slice(2, -1).replace(/^\s+/, '');
+          inner = expr.slice(2, -1).replace(/^[ \t]*\n/, '');
           if (inner.length) {
-            if (options.heredoc) {
+            if (heredoc) {
               inner = inner.replace(RegExp('\\\\' + quote, 'g'), quote);
             }
             nested = lexer.tokenize("(" + (inner) + ")", {
@@ -521,7 +523,7 @@
         i += 1;
       }
       if ((i > pi) && (pi < str.length - 1)) {
-        s = str.slice(pi, i).replace(MULTILINER, options.heredoc ? '\\n' : '');
+        s = str.slice(pi, i).replace(MULTILINER, heredoc ? '\\n' : '');
         tokens.push(['STRING', quote + s + quote]);
       }
       if (tokens[0][0] !== 'STRING') {
@@ -541,7 +543,7 @@
         value = _ref3[1];
         if (tag === 'TOKENS') {
           push.apply(this.tokens, value);
-        } else if (tag === 'STRING' && options.escapeQuotes) {
+        } else if (tag === 'STRING' && escapeQuotes) {
           escaped = value.slice(1, -1).replace(/"/g, '\\"');
           this.token(tag, "\"" + (escaped) + "\"");
         } else {
@@ -582,15 +584,11 @@
     Lexer.prototype.prev = function(index) {
       return this.tokens[this.tokens.length - (index || 1)];
     };
-    Lexer.prototype.match = function(regex, index) {
-      var m;
-      return (m = this.chunk.match(regex)) ? m[index || 0] : false;
-    };
     Lexer.prototype.unfinished = function() {
       var prev, value;
       return (prev = this.prev(2)) && prev[0] !== '.' && (value = this.value()) && NO_NEWLINE.test(value) && !CODE.test(value) && !ASSIGNED.test(this.chunk);
     };
-    Lexer.prototype.oldline = function(str, heredoc) {
+    Lexer.prototype.escapeLines = function(str, heredoc) {
       return str.replace(MULTILINER, heredoc ? '\\n' : '');
     };
     return Lexer;
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 237b4999..20952752 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -340,7 +340,7 @@ exports.Lexer = class Lexer
     doc = doc.replace /\n#{ indent }/g, '\n' if indent
     return doc if herecomment
     doc = doc.replace(/^\n/, '').replace(/#{ options.quote }/g, '\\$&')
-    doc = @oldline doc, on if options.quote is "'"
+    doc = @escapeLines doc, yes if options.quote is "'"
     doc
 
   # A source of ambiguity in our grammar used to be parameter lists in function
@@ -406,8 +406,7 @@ exports.Lexer = class Lexer
     if not i then false else str[0...i]
 
   # Expand variables and expressions inside double-quoted strings using
-  # Ruby-like notation
-  # for substitution of bare variables as well as arbitrary expressions.
+  # Ruby-like notation for substitution of arbitrary expressions.
   #
   #     "Hello #{name.capitalize()}."
   #
@@ -427,7 +426,7 @@ exports.Lexer = class Lexer
         i += 1
       else if expr = @balancedString str[i..], [['#{', '}']]
         if pi < i
-          s = quote + @oldline(str[pi...i], heredoc) + quote
+          s = quote + @escapeLines(str[pi...i], heredoc) + quote
           tokens.push ['STRING', s]
         inner = expr.slice(2, -1).replace /^[ \t]*\n/, ''
         if inner.length
@@ -490,8 +489,8 @@ exports.Lexer = class Lexer
     (value = @value()) and NO_NEWLINE.test(value) and not CODE.test(value) and
     not ASSIGNED.test(@chunk)
 
-  # Converts newlines for string literals
-  oldline: (str, heredoc) ->
+  # Converts newlines for string literals.
+  escapeLines: (str, heredoc) ->
     str.replace MULTILINER, if heredoc then '\\n' else ''
 
 # Constants