/*
* 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;
import kodkod.ast.operator.Multiplicity;
import kodkod.ast.visitor.ReturnVisitor;
import kodkod.ast.visitor.VoidVisitor;
/**
* A variable declaration, such as 'x : lone X'. Declarations
* are used with quantified formulas and comprehension expressions.
*
* @specfield variable: Variable
* @specfield expression: Expression
* @specfield multiplicity: LONE + ONE + SOME + SET
* @invariant variable.arity = expression.arity
* @invariant children = 0->variable + 1->expression
* @author Emina Torlak
*/
public final class Decl extends Decls {
private final Variable variable;
private final Multiplicity mult;
private final Expression expression;
/**
* Constructs a new declaration from the specified variable and
* expression, with the specified order.
*
* @ensures this.variable' = variable && this.expression' = expression && this.multiplicity' = mult
* @throws NullPointerException variable = null || expression = null || mult = null
* @throws IllegalArgumentException variable.arity != expression.arity
*/
Decl(Variable variable, Multiplicity mult, Expression expression) {
if (mult==Multiplicity.NO)
throw new IllegalArgumentException("NO is not a valid multiplicity in a declaration.");
if (variable.arity() != expression.arity())
throw new IllegalArgumentException("Unmatched arities in a declaration: " + variable + " and " + expression);
if (mult != Multiplicity.SET && expression.arity()>1)
throw new IllegalArgumentException("Cannot use multiplicity " + mult + " with an expression of arity > 1.");
this.variable = variable;
this.mult = mult;
this.expression = expression;
}
/**
* Returns the variable in this declaration.
* @return this.variable
*/
public Variable variable() { return variable; }
/**
* Returns the multiplicity in this declaration.
* @return this.multiplicity
*/
public Multiplicity multiplicity() { return mult; }
/**
* Returns the expression in this declaration.
* @return this.exresssion
*/
public Expression expression() { return expression; }
/**
* {@inheritDoc}
* @see kodkod.ast.Node#accept(kodkod.ast.visitor.ReturnVisitor)
*/
public <E, F, D, I> D accept(ReturnVisitor<E, F, D, I> visitor) {
return visitor.visit(this);
}
/**
* {@inheritDoc}
* @see kodkod.ast.Node#accept(kodkod.ast.visitor.VoidVisitor)
*/
public void accept(VoidVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
* @see kodkod.ast.Node#toString()
*/
public String toString() { return variable + ": " + mult + " " + expression; }
}