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// 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 net.starlark.java.syntax;
import java.util.ArrayList;
/** Syntax node for a string literal. */
public final class StringLiteral extends Expression {
// See skyframe.serialization.StringLiteralCodec for custom serialization logic.
private final int startOffset;
private final String value;
private final int endOffset;
StringLiteral(FileLocations locs, int startOffset, String value, int endOffset) {
super(locs, Kind.STRING_LITERAL);
this.startOffset = startOffset;
this.value = value;
this.endOffset = endOffset;
}
/** Returns the value denoted by the string literal */
public String getValue() {
return value;
}
public Location getLocation() {
return locs.getLocation(startOffset);
}
@Override
public int getStartOffset() {
return startOffset;
}
@Override
public int getEndOffset() {
// TODO(adonovan): when we switch to compilation,
// making syntax trees ephemeral, we can afford to
// record the raw literal. This becomes:
// return startOffset + raw.length().
return endOffset;
}
@Override
public void accept(NodeVisitor visitor) {
visitor.visit(this);
}
// -- hooks to support Skyframe serialization without creating a dependency --
/** Returns an opaque serializable object that may be passed to {@link #fromSerialization}. */
public Object getFileLocations() {
return locs;
}
/**
* Returns the value denoted by the Starlark string literal within s.
*
* @throws IllegalArgumentException if s does not contain a valid string literal.
*/
// TODO(bazel-team): We should in principle have an overload that allows non-default FileOptions.
// But currently no FileOptions affect the behavior of this method, except to possibly make it
// throw IAE on non-ASCII data.
public static String unquote(String s) {
// TODO(adonovan): once we have byte compilation, make this function
// independent of the Lexer, which should only validate string literals
// but not unquote them. Clients (e.g. the compiler) can unquote on demand.
ArrayList<SyntaxError> errors = new ArrayList<>();
Lexer lexer = new Lexer(ParserInput.fromLines(s), errors, FileOptions.DEFAULT);
lexer.nextToken();
if (!errors.isEmpty()) {
throw new IllegalArgumentException(errors.get(0).message());
}
if (lexer.start != 0 || lexer.end != s.length() || lexer.kind != TokenKind.STRING) {
throw new IllegalArgumentException("invalid syntax");
}
return (String) lexer.value;
}
/** Constructs a StringLiteral from its serialized components. */
public static StringLiteral fromSerialization(
Object fileLocations, int startOffset, String value, int endOffset) {
return new StringLiteral((FileLocations) fileLocations, startOffset, value, endOffset);
}
}