plugins/InspectionGadgets/src/com/siyeh/ig/psiutils/ComparisonUtils.java

   1 /*
   2  * Copyright 2003-2006 Dave Griffith, Bas Leijdekkers
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.siyeh.ig.psiutils;
  17
  18 import com.intellij.psi.JavaTokenType;
  19 import com.intellij.psi.PsiBinaryExpression;
  20 import com.intellij.psi.PsiExpression;
  21 import com.intellij.psi.PsiJavaToken;
  22 import com.intellij.psi.tree.IElementType;
  23 import org.jetbrains.annotations.NotNull;
  24 import org.jetbrains.annotations.Nullable;
  25
  26 import java.util.HashMap;
  27 import java.util.HashSet;
  28 import java.util.Map;
  29 import java.util.Set;
  30
  31 public class ComparisonUtils {
  32
  33     private ComparisonUtils() {
  34         super();
  35     }
  36
  37     private static final Set<IElementType> s_comparisonTokens =
  38             new HashSet<IElementType>(6);
  39
  40     private static final Map<IElementType,String> s_swappedComparisons =
  41             new HashMap<IElementType, String>(6);
  42
  43     private static final Map<IElementType,String> s_invertedComparisons =
  44             new HashMap<IElementType, String>(6);
  45
  46
  47     static {
  48         s_comparisonTokens.add(JavaTokenType.EQEQ);
  49         s_comparisonTokens.add(JavaTokenType.NE);
  50         s_comparisonTokens.add(JavaTokenType.GT);
  51         s_comparisonTokens.add(JavaTokenType.LT);
  52         s_comparisonTokens.add(JavaTokenType.GE);
  53         s_comparisonTokens.add(JavaTokenType.LE);
  54
  55         s_swappedComparisons.put(JavaTokenType.EQEQ, "==");
  56         s_swappedComparisons.put(JavaTokenType.NE, "!=");
  57         s_swappedComparisons.put(JavaTokenType.GT, "<");
  58         s_swappedComparisons.put(JavaTokenType.LT, ">");
  59         s_swappedComparisons.put(JavaTokenType.GE, "<=");
  60         s_swappedComparisons.put(JavaTokenType.LE, ">=");
  61
  62         s_invertedComparisons.put(JavaTokenType.EQEQ, "!=");
  63         s_invertedComparisons.put(JavaTokenType.NE, "==");
  64         s_invertedComparisons.put(JavaTokenType.GT, "<=");
  65         s_invertedComparisons.put(JavaTokenType.LT, ">=");
  66         s_invertedComparisons.put(JavaTokenType.GE, "<");
  67         s_invertedComparisons.put(JavaTokenType.LE, ">");
  68
  69     }
  70
  71     public static boolean isComparison(@Nullable PsiExpression expression) {
  72         if(!(expression instanceof PsiBinaryExpression)) {
  73             return false;
  74         }
  75         final PsiBinaryExpression binaryExpression =
  76                 (PsiBinaryExpression) expression;
  77         final PsiJavaToken sign = binaryExpression.getOperationSign();
  78         final IElementType tokenType = sign.getTokenType();
  79         return s_comparisonTokens.contains(tokenType);
  80     }
  81
  82     public static String getFlippedComparison(@NotNull PsiJavaToken token) {
  83         final IElementType tokenType = token.getTokenType();
  84         return s_swappedComparisons.get(tokenType);
  85     }
  86
  87     public static boolean isEqualityComparison(
  88             @NotNull PsiBinaryExpression expression) {
  89         final IElementType tokenType = expression.getOperationTokenType();
  90         return tokenType.equals(JavaTokenType.EQEQ) ||
  91                tokenType.equals(JavaTokenType.NE);
  92     }
  93
  94     public static String getNegatedComparison(@NotNull PsiJavaToken token) {
  95         final IElementType tokenType = token.getTokenType();
  96         return s_invertedComparisons.get(tokenType);
  97     }
  98 }