content: /*
   * Copyright 1999-2101 Alibaba Group.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.simpleEL.dialect.ql.parser;
  
  public class CharTypes {
      private final static boolean[] hexFlags = new boolean[256];
      static {
          for (char c = 0; c < hexFlags.length; ++c) {
              if (c >= 'A' && c <= 'F') {
                  hexFlags[c] = true;
              } else if (c >= 'a' && c <= 'f') {
                  hexFlags[c] = true;
              } else if (c >= '0' && c <= '9') {
                  hexFlags[c] = true;
              }
          }
      }
  
      public static boolean isHex(char c) {
          return c < 256 && hexFlags[c];
      }
  
      public static boolean isDigit(char c) {
          return c >= '0' && c <= '9';
      }
  
      private final static boolean[] firstIdentifierFlags = new boolean[256];
      static {
          for (char c = 0; c < firstIdentifierFlags.length; ++c) {
              if (c >= 'A' && c <= 'Z') {
                  firstIdentifierFlags[c] = true;
              } else if (c >= 'a' && c <= 'z') {
                  firstIdentifierFlags[c] = true;
              }
          }
          firstIdentifierFlags['`'] = true;
          firstIdentifierFlags['_'] = true;
          firstIdentifierFlags['$'] = true;
      }
  
      public static boolean isFirstIdentifierChar(char c) {
          return c > firstIdentifierFlags.length || firstIdentifierFlags[c];
      }
  
      private final static boolean[] identifierFlags = new boolean[256];
      static {
          for (char c = 0; c < identifierFlags.length; ++c) {
              if (c >= 'A' && c <= 'Z') {
                  identifierFlags[c] = true;
              } else if (c >= 'a' && c <= 'z') {
                  identifierFlags[c] = true;
              } else if (c >= '0' && c <= '9') {
                  identifierFlags[c] = true;
              }
          }
        //  identifierFlags['`'] = true;
          identifierFlags['_'] = true;
          identifierFlags['$'] = true;
      }
  
      public static boolean isIdentifierChar(char c) {
          return c > identifierFlags.length || identifierFlags[c];
      }
      
      private final static boolean[] whitespaceFlags = new boolean[256];
      static {
          whitespaceFlags[' '] = true;
          whitespaceFlags['\n'] = true;
          whitespaceFlags['\r'] = true;
          whitespaceFlags['\t'] = true;
          whitespaceFlags['\f'] = true;
          whitespaceFlags['\b'] = true;
      }
  
      /**
       * @return false if {@link LayoutCharacters#EOI}
       */
      public static boolean isWhitespace(char c) {
          return c <= whitespaceFlags.length && whitespaceFlags[c];
      }
  
  }
  