// Copyright 2014 The Bazel Authors. All rights reserved. // // 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.google.devtools.build.lib.query2.engine; import com.google.common.base.Function; import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryTaskFuture; import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ThreadSafeMutableSet; import java.util.Collection; import java.util.regex.Pattern; /** * A let expression. * *
expr ::= LET WORD = expr IN expr*/ public class LetExpression extends QueryExpression { private static final String VAR_NAME_PATTERN = "[a-zA-Z_][a-zA-Z0-9_]*$"; // Variables names may be any legal identifier in the C programming language private static final Pattern NAME_PATTERN = Pattern.compile("^" + VAR_NAME_PATTERN); // Variable references are prepended with the "$" character. // A variable named "x" is referenced as "$x". private static final Pattern REF_PATTERN = Pattern.compile("^\\$" + VAR_NAME_PATTERN); static boolean isValidVarReference(String varName) { return REF_PATTERN.matcher(varName).matches(); } public static String getNameFromReference(String reference) { return reference.substring(1); } private final String varName; private final QueryExpression varExpr; private final QueryExpression bodyExpr; public LetExpression(String varName, QueryExpression varExpr, QueryExpression bodyExpr) { this.varName = varName; this.varExpr = varExpr; this.bodyExpr = bodyExpr; } public String getVarName() { return varName; } public QueryExpression getVarExpr() { return varExpr; } public QueryExpression getBodyExpr() { return bodyExpr; } @Override public