Fixed #711: parser accepts numbers ending with a decimal mark again l…

…ike `2.`.

HISTORY.md

@@ -1,6 +1,12 @@
 # History
 
 
+## not yet released, version 3.5.2
+
+- Fixed numbers ending with a decimal mark (like `2.`) not being supported by
+  the parser, solved the ambiguity in the parser. See #707, #711.
+
+
 ## 2016-09-12, version 3.5.1
 
 - Removed a left over console.log statement. Thanks @eknkc.

lib/expression/parse.js

@@ -207,7 +207,7 @@ function factory (type, config, load, typed) {
 
     // skip over whitespaces
     // space, tab, and newline when inside parameters
-    while (c == ' ' || c == '\t' || (c == '\n' && nesting_level)) {
+    while (isWhitespace(c)) {
       // TODO: also take '\r' carriage return as newline? Or does that give problems on mac?
       next();
     }
@@ -283,7 +283,7 @@ function factory (type, config, load, typed) {
           token += c;
           next();
         }
-        if (c == '.' && isDigit(nextPreview())) {
+        if (isDecimalMark(c, nextPreview())) {
           token += c;
           next();
         }
@@ -315,7 +315,7 @@ function factory (type, config, load, typed) {
             next();
           }
 
-          if (c == '.' && isDigit(nextPreview())) {
+          if (isDecimalMark(c, nextPreview())) {
             throw createSyntaxError('Digit expected, got "' + c + '"');
           }
         }
@@ -417,6 +417,27 @@ function factory (type, config, load, typed) {
         || isValidMathSymbol(cPrev, c);
   }
 
+  /**
+   * check whether given character c is a white space character: space, tab, or enter
+   * @param {string} c
+   * @return {boolean}
+   * @private
+   */
+  function isWhitespace (c) {
+    return c == ' ' || c == '\t' || (c == '\n' && nesting_level > 0)
+  }
+
+  /**
+   * Test whether the character c is a decimal mark (dot).
+   * This depends on whether it's followed by a digit or whitespace
+   * @param {string} c
+   * @param {string} cNext
+   * @return {boolean}
+   */
+  function isDecimalMark (c, cNext) {
+    return c == '.' && (isDigit(cNext) || isWhitespace(cNext) || cNext == '')
+  }
+
   /**
    * checks if the given char c is a digit or dot
    * @param {string} c   a string with one character

test/expression/parse.test.js

@@ -223,6 +223,9 @@ describe('parse', function() {
       assert.equal(parseAndEval('0'), 0);
       assert.equal(parseAndEval('3'), 3);
       assert.equal(parseAndEval('3.2'), 3.2);
+      assert.equal(parseAndEval('3.'), 3);
+      assert.equal(parseAndEval('3. '), 3);
+      assert.equal(parseAndEval('3.\t'), 3);
       assert.equal(parseAndEval('003.2'), 3.2);
       assert.equal(parseAndEval('003.200'), 3.2);
       assert.equal(parseAndEval('.2'), 0.2);
@@ -240,7 +243,6 @@ describe('parse', function() {
 
     it('should throw an error with invalid numbers', function() {
       assert.throws(function () {parseAndEval('.'); }, /Value expected/);
-      assert.throws(function () {parseAndEval('4.'); }, /Unexpected operator ./);
       assert.throws(function () {parseAndEval('3.2.2'); }, SyntaxError);
       assert.throws(function () {parseAndEval('3.2e2.2'); }, SyntaxError);