Add support for spaceship operator.

Author: antoineveldhoven

src/twig.expression.js

@@ -212,9 +212,9 @@ module.exports = function (Twig) {
         },
         {
             type: Twig.expression.type.operator.binary,
-            // Match any of ??, ?:, +, *, /, -, %, ~, <, <=, >, >=, !=, ==, **, ?, :, and, b-and, or, b-or, b-xor, in, not in
+            // Match any of ??, ?:, +, *, /, -, %, ~, <=>, <, <=, >, >=, !=, ==, **, ?, :, and, b-and, or, b-or, b-xor, in, not in
             // and, or, in, not in, matches, starts with, ends with can be followed by a space or parenthesis
-            regex: /(^\?\?|^\?:|^(b-and)|^(b-or)|^(b-xor)|^[+\-~%?]|^[:](?!\d\])|^[!=]==?|^[!<>]=?|^\*\*?|^\/\/?|^(and)[(|\s+]|^(or)[(|\s+]|^(in)[(|\s+]|^(not in)[(|\s+]|^(matches)|^(starts with)|^(ends with)|^\.\.)/,
+            regex: /(^\?\?|^\?:|^(b-and)|^(b-or)|^(b-xor)|^[+\-~%?]|^(<=>)|^[:](?!\d\])|^[!=]==?|^[!<>]=?|^\*\*?|^\/\/?|^(and)[(|\s+]|^(or)[(|\s+]|^(in)[(|\s+]|^(not in)[(|\s+]|^(matches)|^(starts with)|^(ends with)|^\.\.)/,
             next: Twig.expression.set.expressions,
             transform(match, tokens) {
                 switch (match[0]) {

src/twig.expression.operator.js

@@ -93,6 +93,11 @@ module.exports = function (Twig) {
                 token.associativity = Twig.expression.operator.leftToRight;
                 break;
 
+            case '<=>':
+                token.precidence = 9;
+                token.associativity = Twig.expression.operator.leftToRight;
+                break;
+
             case '<':
             case '<=':
             case '>':
@@ -275,6 +280,10 @@ module.exports = function (Twig) {
                 stack.push(!Twig.lib.boolval(b));
                 break;
 
+            case '<=>':
+                stack.push(a === b ? 0 : (a < b ? -1 : 1));
+                break;
+
             case '<':
                 stack.push(a < b);
                 break;

test/test.expressions.js

@@ -173,6 +173,13 @@ describe('Twig.js Expressions ->', function () {
             {a: false, b: true},
             {a: false, b: false}
         ];
+        it('should support spaceship operator', function () {
+            const testTemplate = twig({data: '{{ a <=> b }}'});
+            numericTestData.forEach(pair => {
+                const output = testTemplate.render(pair);
+                output.should.equal((pair.a === pair.b ? 0 : (pair.a < pair.b ? -1 : 1)).toString());
+            });
+        });
         it('should support less then', function () {
             const testTemplate = twig({data: '{{ a < b }}'});
             numericTestData.forEach(pair => {