Merge pull request #23 from ambassify/feat/support-range-expressions

feat(expression): add support for range expression
ambassify · Mar 15, 2023 · 1d42b52 · 1d42b52
2 parents 9467a10 + 25b5645
commit 1d42b52
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Showing 2 changed files with 59 additions and 1 deletion.
diff --git a/src/index.js b/src/index.js
@@ -38,7 +38,9 @@ const TAG_CONTROL = TAG | mkid();
 const TAG_ARGUMENT = EXPRESSION | mkid();
 const BLOCK = TEXT | mkid();
 
-const TYPES = {TEXT,TWIG,ERROR,EXPRESSION,VARIABLE,OBJECT,BLOCK,TAG,TAG_ARGUMENT,OBJECT_PROPERTY,OBJECT_VALUE,STRING,FUNCTION,TAG_OUTPUT,TAG_CONTROL,EXPRESSION_LIST,LITERAL,ARRAY,NUMBER,ARGUMENT_LIST,BOOLEAN,NULL,OPERATOR,BRACKETS,FILTER,ACCESS_CHAIN};
+const RANGE = EXPRESSION | mkid();
+
+const TYPES = {TEXT,TWIG,ERROR,EXPRESSION,VARIABLE,OBJECT,BLOCK,TAG,TAG_ARGUMENT,OBJECT_PROPERTY,OBJECT_VALUE,STRING,FUNCTION,TAG_OUTPUT,TAG_CONTROL,EXPRESSION_LIST,LITERAL,ARRAY,NUMBER,ARGUMENT_LIST,BOOLEAN,NULL,OPERATOR,BRACKETS,FILTER,ACCESS_CHAIN,RANGE};
 const NAMES = _invert(TYPES);
 
 const isType = (state, type) => (state & type) == type;
@@ -597,6 +599,29 @@ function matchToken(config = {}, str, state = TEXT, offset = 0, skip = 0, parent
                 tok.add(integer);
             }
 
+        /**
+         * Matching the left-handside expression of the RANGE expression
+         * This path will be taken when we already detected that we are
+         * reading a RANGE.
+         *
+         */
+        } else if (isType(state, EXPRESSION) && tok.parent.is(RANGE) && ms('..')) {
+            tok.end = i;
+            return tok;
+
+        /**
+         * If an expression is followed by `..` it indicates that we are
+         * currently reading expressions that are part of a RANGE expression.
+         *
+         * Read the RANGE and replace the already read expression with a RANGE.
+         */
+        } else if (isType(state, EXPRESSION) && ms('..')) {
+            const range = m(RANGE, tok.start);
+
+            i = range.end;
+            tok.end = range.end;
+            tok.children = [ range ];
+
         /**
          * If the next character is a dot and we are not matching a number,
          * we must be matching a property access.
@@ -723,6 +748,19 @@ function matchToken(config = {}, str, state = TEXT, offset = 0, skip = 0, parent
             tok.end = i;
             return tok;
 
+        /**
+         * Read range expression
+         * example `from..to`
+         */
+        } else if (isType(state, RANGE)) {
+            const from = m(EXPRESSION, i);
+            const to = m(EXPRESSION, from.end + 2);
+
+            tok.end = to.end;
+            tok.add(from);
+            tok.add(to);
+            return tok;
+
         /**
          * Detect the operator that the expression statement found.
          */

diff --git a/test/expressions.js b/test/expressions.js
@@ -76,6 +76,26 @@ describe('toAST', () => {
             assert.equal(take(fnBar, 0, 0, 0, 'value'), 'baz');
         });
 
+        it('should handle for loop with range', () => {
+            const ast = toAST(`
+                {% for idx in variable_1..test %}
+                    {{ idx }},
+                {% endfor %}
+            `);
+
+            const range = take(ast, 1, 0, 2, 0);
+            assert.equal(range.type, 'RANGE');
+
+            assert.equal(range.children.length, 2);
+
+            const [ from, to ] = range.children;
+            assert.equal(from.type, 'EXPRESSION');
+            assert.equal(take(from, 0, 'name'), 'variable_1');
+
+            assert.equal(to.type, 'EXPRESSION');
+            assert.equal(take(to, 0, 'name'), 'test');
+        });
+
         describe('# regression', () => {
 
             it('should handle functions starting with in', () => {