Support scientific notation

silentmatt · Oct 10, 2016 · e2a6f77 · e2a6f77
1 parent 2e9b77b
commit e2a6f77
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Showing 2 changed files with 76 additions and 1 deletion.
diff --git a/parser.js b/parser.js
@@ -769,8 +769,10 @@ TokenStream.prototype.isNumber = function () {
   var startColumn = this.column;
   var foundDot = false;
   var foundDigits = false;
+  var char;
+
   while (this.pos < this.expression.length) {
-    var char = this.expression.charAt(this.pos);
+    char = this.expression.charAt(this.pos);
     if ((char >= '0' && char <= '9') || (!foundDot && char === '.')) {
       if (char === '.') {
         foundDot = true;
@@ -786,6 +788,38 @@ TokenStream.prototype.isNumber = function () {
     }
   }
 
+  if (r) {
+    startPos = this.pos;
+    startColumn = this.column;
+  }
+
+  if (char === 'e' || char === 'E') {
+    this.pos++;
+    this.column++;
+    var expString = 'e';
+    var validExponent = false;
+    while (this.pos < this.expression.length) {
+      char = this.expression.charAt(this.pos);
+      if ((char === '+' || char === '-') && expString === 'e') {
+        expString += char;
+      } else if (char >= '0' && char <= '9') {
+        validExponent = true;
+        expString += char;
+      } else {
+        break;
+      }
+      this.pos++;
+      this.column++;
+    }
+
+    if (validExponent) {
+      str += expString;
+    } else {
+      this.pos = startPos;
+      this.column = startPos;
+    }
+  }
+
   if (r) {
     this.current = this.newToken(TNUMBER, parseFloat(str));
   } else {

diff --git a/test/parser.js b/test/parser.js
@@ -48,12 +48,53 @@ describe('Parser', function () {
       expect(parser.evaluate('2/123')).to.equal(2 / 123);
     });
 
+    it('should parse numbers using scientific notation', function () {
+      expect(parser.evaluate('123e2')).to.equal(12300);
+      expect(parser.evaluate('123E2')).to.equal(12300);
+      expect(parser.evaluate('123e12')).to.equal(123000000000000);
+      expect(parser.evaluate('123e+12')).to.equal(123000000000000);
+      expect(parser.evaluate('123E+12')).to.equal(123000000000000);
+      expect(parser.evaluate('123e-12')).to.equal(0.000000000123);
+      expect(parser.evaluate('123E-12')).to.equal(0.000000000123);
+      expect(parser.evaluate('1.7e308')).to.equal(1.7e308);
+      expect(parser.evaluate('1.7e-308')).to.equal(1.7e-308);
+      expect(parser.evaluate('123.e3')).to.equal(123000);
+      expect(parser.evaluate('123.456e+1')).to.equal(1234.56);
+      expect(parser.evaluate('.456e-3')).to.equal(0.000456);
+      expect(parser.evaluate('0.456')).to.equal(0.456);
+      expect(parser.evaluate('0e3')).to.equal(0);
+      expect(parser.evaluate('0e-3')).to.equal(0);
+      expect(parser.evaluate('0e+3')).to.equal(0);
+      expect(parser.evaluate('.0e+3')).to.equal(0);
+      expect(parser.evaluate('.0e-3')).to.equal(0);
+      expect(parser.evaluate('123e5+4')).to.equal(12300004);
+      expect(parser.evaluate('123e+5+4')).to.equal(12300004);
+      expect(parser.evaluate('123e-5+4')).to.equal(4.00123);
+      expect(parser.evaluate('123e0')).to.equal(123);
+      expect(parser.evaluate('123e01')).to.equal(1230);
+      expect(parser.evaluate('123e+00000000002')).to.equal(12300);
+      expect(parser.evaluate('123e-00000000002')).to.equal(1.23);
+      expect(parser.evaluate('e1', { e1: 42 })).to.equal(42);
+      expect(parser.evaluate('e+1', { e: 12 })).to.equal(13);
+    });
+
     it('should fail on invalid numbers', function () {
       expect(function () { parser.parse('123..'); }).to.throw(Error);
       expect(function () { parser.parse('0..123'); }).to.throw(Error);
       expect(function () { parser.parse('0..'); }).to.throw(Error);
       expect(function () { parser.parse('.0.'); }).to.throw(Error);
       expect(function () { parser.parse('.'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e+'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e-'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e++4'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e--4'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e+-4'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e4-'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23ee4'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23ee.4'); }).to.throw(Error);
+      expect(function () { parser.parse('1.23e4.0'); }).to.throw(Error);
+      expect(function () { parser.parse('123e.4'); }).to.throw(Error);
     });
 
     it('should fail on unknown characters', function () {