content: /* 
   * Kodkod -- Copyright (c) 2005-present, Emina Torlak
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  package kodkod.ast.operator;
  
  
  
  /**
   * Enumerate unary (-, ~, abs, sgn), binary (+, *, &, |, -, /, %, >>, >>>, <<) and nary (+, *, &, |) operators on integer expressions.
   * @specfield op: (int->lone IntExpression) -> IntExpression
   * @invariant all args: seq IntExpression, out: IntExpression | args->out in op => (out.children = args && out.op = this)
   */
  public enum IntOperator {
  	/** `+' operator */
  	PLUS 		{ public String toString() { return "+"; } },
  	/** `*' operator */
  	MULTIPLY 	{ public String toString() { return "*"; } }, 
  	/** `-' operator */
  	MINUS 		{ public String toString() { return "-"; } },
  	/** `/' operator */
  	DIVIDE 		{ public String toString() { return "/"; } },
  	/** `%' operator */
  	MODULO 		{ public String toString() { return "%"; } },
  	/** Bitwise AND operator */
  	AND 		{ public String toString() { return "&"; } },
  	/** Bitwise OR operator */
  	OR 			{ public String toString() { return "|"; } }, 
  	/** Bitwise XOR operator */
  	XOR 		{ public String toString() { return "^"; } }, 
  	/** Left shift operator */
  	SHL 		{ public String toString() { return "<<"; } }, 
  	/** Right shift operator with zero extension */
  	SHR 		{ public String toString() { return ">>>"; } }, 
  	/** Right shift operator with sign extension */
  	SHA 		{ public String toString() { return ">>"; } },
  	/** unary negation (`-') operator */
  	NEG 		{ public String toString() { return "-"; } },
  	/** bit negation (`~') operator */
  	NOT 		{ public String toString() { return "~"; } }, 
  	/** absolute value function */
  	ABS 		{ public String toString() { return "abs";} }, 
  	/** signum function */
  	SGN 		{ public String toString() { return "sgn"; } };
  
  	static final int unary = NEG.index() | NOT.index() | ABS.index() | SGN.index();
  	
  	static final int binary = ~unary;
  	
  	static final int nary = PLUS.index() | MULTIPLY.index() | AND.index() | OR.index();
  	
  	private final int index() { return 1<<ordinal(); }
  	
  	/**
       * Returns true if this is a unary operator.
       * @return true if this is a unary operator.
       */
      public final boolean unary() { return (unary & index())!=0; }
      
      /**
       * Returns true if this is a binary operator.
       * @return true if this is a binary operator.
       */
      public final boolean binary() { return (binary & index())!=0; }
      
      /**
       * Returns true if this is an nary operator.
       * @return true if this is an nary operator.
       */
      public final boolean nary() { return (nary & index())!=0; }
  }