From 50f94911b1e73549ca21859d70faee687332589c Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Fri, 7 Jun 2013 16:14:22 -0600
Subject: [PATCH] Scan string literals

---
 src/ol/expression/lexer.js            |  35 ++++++++-
 test/spec/ol/expression/lexer.test.js | 105 ++++++++++++++++++++++++++
 2 files changed, 139 insertions(+), 1 deletion(-)

diff --git a/src/ol/expression/lexer.js b/src/ol/expression/lexer.js
index ea564bc6f7..881fb26361 100644
--- a/src/ol/expression/lexer.js
+++ b/src/ol/expression/lexer.js
@@ -691,7 +691,40 @@ ol.expression.Lexer.prototype.scanPunctuator_ = function() {
  * @private
  */
 ol.expression.Lexer.prototype.scanStringLiteral_ = function() {
-  throw new Error('Not yet implemented');
+  var quote = this.getCurrentCharCode_();
+  goog.asserts.assert(quote === ol.expression.Char.SINGLE_QUOTE ||
+      quote === ol.expression.Char.DOUBLE_QUOTE,
+      'Strings must start with a quote: ' + String.fromCharCode(quote));
+
+  var start = this.index_;
+  this.increment_(1);
+
+  var str = '';
+  var code;
+  while (this.index_ < this.length_) {
+    code = this.getCurrentCharCode_();
+    this.increment_(1);
+    if (code === quote) {
+      quote = 0;
+      break;
+    }
+    // look for escaped quote or backslash
+    if (code === ol.expression.Char.BACKSLASH) {
+      str += this.getCurrentChar_();
+      this.increment_(1);
+    } else {
+      str += String.fromCharCode(code);
+    }
+  }
+
+  if (quote !== 0) {
+    throw new Error('Unterminated string literal');
+  }
+
+  return {
+    type: ol.expression.TokenType.STRING_LITERAL,
+    value: str
+  };
 };
 
 
diff --git a/test/spec/ol/expression/lexer.test.js b/test/spec/ol/expression/lexer.test.js
index 0bb094a281..69aff7a6a3 100644
--- a/test/spec/ol/expression/lexer.test.js
+++ b/test/spec/ol/expression/lexer.test.js
@@ -147,6 +147,111 @@ describe('ol.expression.Lexer', function() {
 
   });
 
+  describe('#scanStringLiteral_()', function() {
+
+    function scan(source) {
+      var lexer = new ol.expression.Lexer(source);
+      return lexer.scanStringLiteral_();
+    }
+
+    it('parses double quoted string', function() {
+      var token = scan('"my string"');
+      expect(token.value).to.be('my string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with internal single quotes', function() {
+      var token = scan('"my \'quoted\' string"');
+      expect(token.value).to.be('my \'quoted\' string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with escaped double quotes', function() {
+      var token = scan('"my \\"quoted\\" string"');
+      expect(token.value).to.be('my "quoted" string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with escaped backslash', function() {
+      var token = scan('"my \\\ string"');
+      expect(token.value).to.be('my \ string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with unicode escape sequences', function() {
+      var token = scan('"\u006f\u006c\u0033"');
+      expect(token.value).to.be('ol3');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with hex escape sequences', function() {
+      var token = scan('"\x6f\x6c\x33"');
+      expect(token.value).to.be('ol3');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses double quoted string with tab', function() {
+      var token = scan('"a\ttab"');
+      expect(token.value).to.be('a\ttab');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('throws on unterminated double quote', function() {
+      expect(function() {
+        scan('"never \'ending\' string');
+      }).to.throwException();
+    });
+
+    it('parses single quoted string', function() {
+      var token = scan('\'my string\'');
+      expect(token.value).to.be('my string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with internal double quotes', function() {
+      var token = scan('\'my "quoted" string\'');
+      expect(token.value).to.be('my "quoted" string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with escaped single quotes', function() {
+      var token = scan('\'my \\\'quoted\\\' string\'');
+      expect(token.value).to.be('my \'quoted\' string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with escaped backslash', function() {
+      var token = scan('\'my \\\ string\'');
+      expect(token.value).to.be('my \ string');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with unicode escape sequences', function() {
+      var token = scan('\'\u006f\u006c\u0033\'');
+      expect(token.value).to.be('ol3');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with hex escape sequences', function() {
+      var token = scan('\'\x6f\x6c\x33\'');
+      expect(token.value).to.be('ol3');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('parses single quoted string with tab', function() {
+      var token = scan('\'a\ttab\'');
+      expect(token.value).to.be('a\ttab');
+      expect(token.type).to.be(ol.expression.TokenType.STRING_LITERAL);
+    });
+
+    it('throws on unterminated single quote', function() {
+      expect(function() {
+        scan('\'never "ending" string');
+      }).to.throwException();
+    });
+
+  });
+
 });
 
 goog.require('ol.expression.Lexer');