/*
* 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;
/**
* Enumerates binary (&&, ||, =>, <=>) and nary (&&, ||) logical operators.
* @specfield op: (int->lone Formula) -> Formula
* @invariant all args: seq Formula, out: Formula | args->out in op => (out.children = args && out.op = this)
*/
public enum FormulaOperator {
/** Logical AND operator. */
AND { public String toString() { return "&&"; } },
/** Logical OR operator. */
OR { public String toString() { return "||"; } },
/** Logical bi-implication operator. */
IFF { public String toString() { return "<=>"; } },
/** Logical implication operator. */
IMPLIES { public String toString() { return "=>"; } };
static final int nary = (1<<AND.ordinal()) | (1<<OR.ordinal());
/**
* Returns true if this is an nary operator.
* @return true if this is an nary operator
*/
public final boolean nary() { return (nary & (1<<ordinal()))!=0; }
}