glayzzle#75 fix precedence resolution

Author: ichiriac

src/ast.js

@@ -124,6 +124,85 @@ AST.prototype.position = function(parser) {
   );
 };
 
+
+// operators in ascending order of precedence
+AST.precedence = {};
+var binOperatorsPrecedence = [
+  ['or'],
+  ['xor'],
+  ['and'],
+  // TODO: assignment / not sure that PHP allows this with expressions
+  ['retif'],
+  ['??'],
+  ['||'],
+  ['&&'],
+  ['|'],
+  ['^'],
+  ['&'],
+  ['==', '!=', '===', '!==', /* '<>', */ '<=>'],
+  ['<', '<=', '>', '>='],
+  ['<<', '>>'],
+  ['+', '-', '.'],
+  ['*', '/', '%'],
+  ['!'],
+  ['instanceof'],
+  // TODO: typecasts
+  // TODO: [ (array)
+  // TODO: clone, new
+].forEach(function (list, index) {
+  list.forEach(function (operator) {
+    AST.precedence[operator] = index + 1;
+  });
+});
+
+
+/**
+ * Check and fix precence, by default using right
+ */
+AST.prototype.resolvePrecedence = function(result) {
+  var buffer;
+  // handling precendence
+  if (result.kind === 'bin') {
+    if (result.right && result.right.kind === 'bin') {
+      var lLevel = AST.precedence[result.type];
+      var rLevel = AST.precedence[result.right.type];
+      if (lLevel && rLevel && rLevel <= lLevel) {
+        // https://github.com/glayzzle/php-parser/issues/79
+        // shift precedence
+        buffer = result.right;
+        result.right = result.right.left;
+        buffer.left = this.resolvePrecedence(result);
+        result = buffer;
+      }
+    }
+  } else if (result.kind === 'unary') {
+    // https://github.com/glayzzle/php-parser/issues/75
+    if (result.what) {
+      // unary precedence is allways lower
+      if (result.what.kind === 'bin') {
+        buffer = result.what;
+        result.what = result.what.left;
+        buffer.left = this.resolvePrecedence(result);
+        result = buffer;
+      } else if (result.what.kind === 'retif') {
+        buffer = result.what;
+        result.what = result.what.test;
+        buffer.test = this.resolvePrecedence(result);
+        result = buffer;
+      }
+    }
+  } else if (result.kind === 'retif') {
+    // https://github.com/glayzzle/php-parser/issues/77
+    if (result.falseExpr && result.falseExpr.kind === 'retif') {
+      buffer = result.falseExpr;
+      result.falseExpr = buffer.test;
+      buffer.test = this.resolvePrecedence(result);
+      result = buffer;
+    }
+  }
+  return result;
+};
+
 /**
  * Prepares an AST node
  * @param {String|null} kind - Defines the node type
@@ -172,22 +251,7 @@ AST.prototype.prepare = function(kind, parser) {
     }
     var result = Object.create(node.prototype);
     node.apply(result, args);
-    if (
-      result.kind === 'bin' &&
-      result.right &&
-      typeof result.right.precedence === 'function'
-    ) {
-      var out = result.right.precedence(result);
-      if (out) { // shift with precedence
-        result = out;
-      }
-    } else if (result.kind === 'unary' && result.what) {
-      var out = result.precedence(result.what);
-      if (out) { // shift with precedence
-        result = out;
-      }
-    }
-    return result;
+    return self.resolvePrecedence(result);
   };
 };
 

src/ast/bin.js

@@ -7,37 +7,6 @@
 
 var Operation = require('./operation');
 var KIND = 'bin';
-
-// operators in ascending order of precedence
-var binOperatorsPrecedence = [
-  ['or'],
-  ['xor'],
-  ['and'],
-  // TODO: assignment / not sure that PHP allows this with expressions
-  ['retif'],
-  ['??'],
-  ['||'],
-  ['&&'],
-  ['|'],
-  ['^'],
-  ['&'],
-  ['==', '!=', '===', '!==', /* '<>', */ '<=>'],
-  ['<', '<=', '>', '>='],
-  ['<<', '>>'],
-  ['+', '-', '.'],
-  ['*', '/', '%'],
-  ['!'],
-  ['instanceof'],
-  // TODO: typecasts
-  // TODO: [ (array)
-  // TODO: clone, new
-];
-
-/*
-x OP1 (y OP2 z)
-z OP1 (x OP2 y)
-z OP2 (x OP1 y)
-*/
 /**
  * Binary operations
  * @constructor Bin
@@ -53,23 +22,4 @@ var Bin = Operation.extends(function Bin(type, left, right, location) {
   this.right = right;
 });
 
-Bin.prototype.precedence = function(node) {
-  var lLevel = Bin.precedence[node.type];
-  var rLevel = Bin.precedence[this.type];
-  if (lLevel && rLevel && rLevel < lLevel) {
-    // shift precedence
-    node.right = this.left;
-    this.left = node;
-    return this;
-  }
-};
-
-// define nodes shifting
-Bin.precedence = {};
-binOperatorsPrecedence.forEach(function (list, index) {
-  list.forEach(function (operator) {
-    Bin.precedence[operator] = index + 1;
-  });
-});
-
 module.exports = Bin;

src/ast/retif.js

@@ -7,8 +7,6 @@
 
 var Statement = require('./statement');
 var KIND = 'retif';
-var Bin = require('./bin');
-var PRECEDENCE = Bin.precedence[KIND];
 
 /**
  * Defines a short if statement that returns a value
@@ -25,21 +23,4 @@ var RetIf = Statement.extends(function RetIf(test, trueExpr, falseExpr, location
   this.falseExpr = falseExpr;
 });
 
-/**
- * Handles precedence over items
- */
-RetIf.prototype.precedence = function(node) {
-  var what = node.kind === 'bin' ? node.type : node.kind;
-  var lLevel = Bin.precedence[what];
-  if (lLevel && PRECEDENCE < lLevel) {
-    if (node.kind === 'bin') {
-      node.right = this.test;
-      this.test = node;
-      return this;
-    } else {
-      throw new Error('@todo ' + node.kind);
-    }
-  }
-};
-
 module.exports = RetIf;

src/ast/unary.js

@@ -21,16 +21,4 @@ var Unary = Operation.extends(function Unary(type, what, location) {
   this.what = what;
 });
 
-Unary.prototype.precedence = function(node) {
-  if (node.kind === 'bin') {
-    this.what = node.left;
-    node.left = this;
-    return node;
-  } else if (node.kind === 'retif') {
-    this.what = node.test;
-    node.test = this;
-    return node;
-  }
-};
-
 module.exports = Unary;