156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson/* 256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Copyright (C) 2010 Google Inc. 356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Licensed under the Apache License, Version 2.0 (the "License"); 556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * you may not use this file except in compliance with the License. 656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * You may obtain a copy of the License at 756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * http://www.apache.org/licenses/LICENSE-2.0 956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 1056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Unless required by applicable law or agreed to in writing, software 1156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * distributed under the License is distributed on an "AS IS" BASIS, 1256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * See the License for the specific language governing permissions and 1456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * limitations under the License. 1556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson */ 1656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 1756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonpackage com.google.clearsilver.jsilver.syntax; 1856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 1956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.analysis.DepthFirstAdapter; 2056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AAddExpression; 2156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ADecimalExpression; 2256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ADivideExpression; 2356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AEqExpression; 2456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AFunctionExpression; 2556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AHexExpression; 2656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AModuloExpression; 2756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.AMultiplyExpression; 2856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANameVariable; 2956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANeExpression; 3056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANegativeExpression; 3156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANumericAddExpression; 3256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANumericEqExpression; 3356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANumericExpression; 3456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ANumericNeExpression; 3556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.ASubtractExpression; 3656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.PExpression; 3756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonimport com.google.clearsilver.jsilver.syntax.node.PVariable; 3856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 3956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson/** 4056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * AST visitor to add numeric expressions to the syntax tree. 4156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 4256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <p> 4356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * There are three types of expression we need to process; addition, equality and inequality. By 4456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * default these are treated as string expressions unless one of the operands is numeric, in which 4556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * case the original expression is replaced with its numeric equivalent. This behavior seems to 4656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * exactly match Clearsilver's type inference system. 4756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 4856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <p> 4956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Note how we preprocess our node before testing to see is it should be replaced. This is very 5056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * important because it means that type inference is propagated correctly along compound 5156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * expressions. Consider the expression: 5256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 5356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <pre>#a + b + c</pre> 5456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 5556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * which is parsed (left-to-right) as: 5656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 5756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <pre>(#a + b) + c</pre> 5856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 5956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * When we process the left-hand-side sub-expression {@code #a + b} it is turned into a numeric 6056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * addition (due to the forced numeric value on the left). Then when we process the main expression 6156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * we propagate the numeric type into it. 6256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 6356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <p> 6456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * This matches Clearsilver behavior but means that the expressions: 6556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 6656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <pre>#a + b + c</pre> 6756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 6856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * and 6956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 7056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * <pre>c + b + #a</pre> 7156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * 7256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * produce different results (the {@code c + b} subexpression in the latter is evaluated as string 7356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * concatenation and not numeric addition). 7456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson */ 7556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodsonpublic class TypeResolver extends DepthFirstAdapter { 7656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 7756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson @Override 7856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson public void caseAAddExpression(AAddExpression node) { 7956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson super.caseAAddExpression(node); 8056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression lhs = node.getLeft(); 8156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression rhs = node.getRight(); 8256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if (isNumeric(lhs) || isNumeric(rhs)) { 8356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson node.replaceBy(new ANumericAddExpression(lhs, rhs)); 8456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 8556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 8656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 8756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson @Override 8856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson public void caseAEqExpression(AEqExpression node) { 8956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson super.caseAEqExpression(node); 9056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression lhs = node.getLeft(); 9156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression rhs = node.getRight(); 9256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if (isNumeric(lhs) || isNumeric(rhs)) { 9356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson node.replaceBy(new ANumericEqExpression(lhs, rhs)); 9456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 9556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 9656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 9756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson @Override 9856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson public void caseANeExpression(ANeExpression node) { 9956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson super.caseANeExpression(node); 10056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression lhs = node.getLeft(); 10156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PExpression rhs = node.getRight(); 10256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if (isNumeric(lhs) || isNumeric(rhs)) { 10356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson node.replaceBy(new ANumericNeExpression(lhs, rhs)); 10456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 10556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 10656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 10756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson /** 10856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Determines whether the given (sub)expression is numeric, which in turn means that its parent 10956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * expression should be treated as numeric if possible. 11056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson */ 11156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson static boolean isNumeric(PExpression node) { 11256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson return node instanceof ANumericExpression // forced numeric (#a) 11356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof ANumericAddExpression // numeric addition (a + b) 11456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof ASubtractExpression // subtraction (a - b) 11556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof AMultiplyExpression // multiplication (a * b) 11656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof ADivideExpression // division (a / b) 11756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof AModuloExpression // modulu (x % b) 11856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof ADecimalExpression // literal decimal (213) 11956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof AHexExpression // literal hex (0xabc or 0XABC) 12056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || node instanceof ANegativeExpression // negative expression (-a) 12156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson || isNumericFunction(node); // numeric function (subcount) 12256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 12356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson 12456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson /** 12556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson * Determine if the given expression represents a numeric function. 12656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson */ 12756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson static boolean isNumericFunction(PExpression node) { 12856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if (!(node instanceof AFunctionExpression)) { 12956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson return false; 13056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 13156ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson PVariable functionName = ((AFunctionExpression) node).getName(); 13256ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if (functionName instanceof ANameVariable) { 13356ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson String name = ((ANameVariable) functionName).getWord().getText(); 13456ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson if ("max".equals(name) || "min".equals(name) || "abs".equals(name) || "subcount".equals(name)) { 13556ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson return true; 13656ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 13756ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 13856ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson return false; 13956ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson } 14056ed4167b942ec265f9cee70ac4d71d10b3835ceBen Dodson} 141