| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.jena.sparql.expr; |
| |
| import java.util.Set; |
| |
| import org.apache.jena.sparql.algebra.Op; |
| import org.apache.jena.sparql.core.Var; |
| import org.apache.jena.sparql.engine.binding.Binding; |
| import org.apache.jena.sparql.expr.nodevalue.XSDFuncOp; |
| import org.apache.jena.sparql.function.FunctionEnv; |
| import org.apache.jena.sparql.graph.NodeTransform; |
| import org.apache.jena.sparql.sse.writers.WriterExpr; |
| |
| /** |
| * A node that is a constraint expression that can be evaluated |
| * An {@link Expr} is already a Constraint - ExprNode is the base implementation |
| * of all {@link Expr} classes that provides the Constraint machinery. |
| */ |
| |
| public abstract class ExprNode implements Expr |
| { |
| @Override |
| public boolean isSatisfied(Binding binding, FunctionEnv funcEnv) { |
| try { |
| NodeValue v = eval(binding, funcEnv); |
| boolean b = XSDFuncOp.booleanEffectiveValue(v); |
| return b; |
| } |
| catch (ExprEvalException ex) { |
| return false; |
| } |
| } |
| |
| public boolean isExpr() { return true; } |
| public final Expr getExpr() { return this; } |
| |
| // --- interface Constraint |
| |
| @Override |
| public abstract NodeValue eval(Binding binding, FunctionEnv env); |
| |
| @Override |
| public final Set<Var> getVarsMentioned() { return ExprVars.getVarsMentioned(this); } |
| |
| @Override |
| public abstract int hashCode(); |
| |
| @Override |
| public final boolean equals(Object other) { |
| if ( other == null ) |
| return false; |
| if ( this == other ) |
| return true; |
| if ( !(other instanceof Expr) ) |
| return false; |
| return equals((Expr)other, false); |
| } |
| |
| @Override |
| public final boolean equalsBySyntax(Expr other) { |
| if ( other == null ) return false; |
| if ( this == other ) return true; |
| return equals(other, true); |
| } |
| |
| @Override |
| public abstract boolean equals(Expr other, boolean bySyntax); |
| |
| protected static NodeValue eval(Binding binding, FunctionEnv funcEnv, Expr expr) { |
| if ( expr == null ) return null; |
| return expr.eval(binding, funcEnv); |
| } |
| |
| @Override |
| final public Expr deepCopy() { return copySubstitute(null); } |
| |
| @Override |
| public abstract Expr copySubstitute(Binding binding); |
| |
| @Override |
| public abstract Expr applyNodeTransform(NodeTransform transform); |
| |
| // ---- Default implementations |
| @Override |
| public boolean isVariable() { return false; } |
| @Override |
| public String getVarName() { return null; } //throw new ExprException("Expr.getVarName called on non-variable"); } |
| @Override |
| public ExprVar getExprVar() { return null; } //throw new ExprException("Expr.getVar called on non-variable"); } |
| @Override |
| public Var asVar() { return null; } //throw new ExprException("Expr.getVar called on non-variable"); } |
| |
| @Override |
| public boolean isConstant() { return false; } |
| @Override |
| public NodeValue getConstant() { return null; } // throw new ExprException("Expr.getConstant called on non-constant"); } |
| |
| @Override |
| public boolean isFunction() { return false; } |
| @Override |
| public ExprFunction getFunction() { return null; } |
| |
| public boolean isGraphPattern() { return false; } |
| public Op getGraphPattern() { return null; } |
| @Override |
| public String toString() { return WriterExpr.asString(this); } |
| } |