Merge pull request #1 from nobitlost/dev_CSE-332

Fixed nested curly braces parsing
electricimp · Apr 10, 2017 · 2e7717d · 2e7717d
2 parents 0802f99 + ff97c3f
commit 2e7717d
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Showing 2 changed files with 98 additions and 4 deletions.
diff --git a/spec/AstParser/basic.spec.js b/spec/AstParser/basic.spec.js
@@ -197,4 +197,55 @@ describe('AstParser', () => {
       }
     ]);
   });
+
+  it('should parse enclosed curly brackets', () => {
+    const res = p.parse
+(`@macro set(val)
+local var1 = @{val};
+@end
+@{set('{}')}
+`);
+   //console.log(JSON.stringify(res, null, '    '));
+
+   expect(res).toEqual([
+    {
+        "_line": 1,
+        "type": "macro",
+        "declaration": "set(val)",
+        "body": [
+            {
+                "_line": 2,
+                "type": "output",
+                "value": "local var1 = ",
+                "computed": true
+            },
+            {
+                "_line": 2,
+                "type": "output",
+                "value": "val",
+                "computed": false
+            },
+            {
+                "_line": 2,
+                "type": "output",
+                "value": ";\n",
+                "computed": true
+            }
+        ]
+    },
+    {
+        "_line": 4,
+        "type": "output",
+        "value": "set('{}')",
+        "computed": false
+    },
+    {
+        "_line": 4,
+        "type": "output",
+        "value": "\n",
+        "computed": true
+    }
+    ]);
+  });
+
 });
diff --git a/src/AstParser.js b/src/AstParser.js
@@ -4,6 +4,8 @@
 
 'use strict';
 
+const jsep = require('jsep');
+
 // instruction types
 const INSTRUCTIONS = require('./Machine').INSTRUCTIONS;
 
@@ -57,6 +59,10 @@ const Errors = {
  */
 class AstParser {
 
+  constructor() {
+    this._initParser();
+  }
+
   /**
    * Parse source into AST
    *
@@ -69,6 +75,22 @@ class AstParser {
     );
   }
 
+  _initParser() {
+    this._jsep = jsep;
+
+    // remove binary ops
+    this._jsep.removeBinaryOp('!==');
+    this._jsep.removeBinaryOp('===');
+    this._jsep.removeBinaryOp('>>');
+    this._jsep.removeBinaryOp('<<');
+    this._jsep.removeBinaryOp('>>>');
+    this._jsep.removeBinaryOp('&');
+    this._jsep.removeBinaryOp('^');
+
+    // remove unary ops
+    this._jsep.removeUnaryOp('~');
+  }
+
   /**
    * Returns tokens generator
    * @param {string} source
@@ -191,7 +213,7 @@ class AstParser {
         // do nothing
       } else {
         // split source fragment into computed/uncomputed chunks
-        yield* AstParser._tokenizeSourceFragment(text, 1 + i);
+        yield* this._tokenizeSourceFragment(text, 1 + i);
       }
     }
   }
@@ -202,13 +224,34 @@ class AstParser {
    * @param {number} line #
    * @private
    */
-  static * _tokenizeSourceFragment(fragment, line) {
+  * _tokenizeSourceFragment(fragment, line) {
 
     let matches;
 
     // extract source fragments and inline expressions
     while (matches = /@{(.*?)}/.exec(fragment)) {
 
+      let expArg = null;
+      let parsed = false;
+      let argLen = fragment.length - matches.index - 3; // 3 = length("@{}")
+
+      // find a sequence of a maximum length that is a valid expression
+      while (argLen >= 0) {
+        try {
+          expArg = fragment.substr(matches.index + 2, argLen); // 2 = length("@{")
+          this._jsep(expArg);
+          parsed = true;
+          break;
+        } catch (e) {
+          // take it easy and keep trying
+        }
+        argLen--;
+      }
+
+      if (!parsed || fragment.charAt(matches.index + 2 + argLen) != '}') {
+        throw new Errors.SyntaxError(`Syntax error in the inline instruction at (${this.file}:${line})`);
+      }
+
       // push source fragment
       if (matches.index > 0) {
         yield {
@@ -222,10 +265,10 @@ class AstParser {
       yield {
         _line: line,
         type: TOKENS.INLINE_EXPRESSION,
-        args: [matches[1]]
+        args: [expArg]
       };
 
-      fragment = fragment.substr(matches.index + matches[0].length);
+      fragment = fragment.substr(matches.index + 2 + argLen + 1); // match.index + length("@{") + length(arg) + length("}")
     }
 
     // push last source fragment