| // 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 static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.common.base.Joiner; |
| import com.google.common.base.Preconditions; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.CharBuffer; |
| import java.nio.file.Files; |
| import java.nio.file.Paths; |
| |
| /** |
| * The apparent name and contents of a source file, for consumption by the parser. The file name |
| * appears in the location information in the syntax tree, and in error messages, but the Starlark |
| * interpreter will not attempt to open the file. However, the default behavior of {@link |
| * EvalException#getMessageWithStack} attempts to read the specified file when formatting a stack |
| * trace. |
| * |
| * <p>The parser consumes a stream of chars (UTF-16 codes), and the syntax positions reported by |
| * {@link Node#getStartOffset} and {@link Location.column} are effectively indices into a char |
| * array. |
| */ |
| public final class ParserInput { |
| |
| private final String file; |
| private final char[] content; |
| |
| private ParserInput(char[] content, String file) { |
| this.content = content; |
| this.file = Preconditions.checkNotNull(file); |
| } |
| |
| /** Returns the content of the input source. Callers must not modify the result. */ |
| char[] getContent() { |
| return content; |
| } |
| |
| /** Returns the apparent file name of the input source. */ |
| public String getFile() { |
| return file; |
| } |
| |
| /** |
| * Returns an input source that uses the name and content of the specified UTF-8-encoded text |
| * file. |
| */ |
| public static ParserInput readFile(String file) throws IOException { |
| byte[] utf8 = Files.readAllBytes(Paths.get(file)); |
| return fromUTF8(utf8, file); |
| } |
| |
| /** Returns an unnamed input source that reads from a list of strings, joined by newlines. */ |
| public static ParserInput fromLines(String... lines) { |
| return fromString(Joiner.on("\n").join(lines), ""); |
| } |
| |
| /** |
| * Returns an input source that reads from a UTF-8-encoded byte array. The caller is free to |
| * subsequently mutate the array. |
| */ |
| public static ParserInput fromUTF8(byte[] bytes, String file) { |
| CharBuffer cb = UTF_8.decode(ByteBuffer.wrap(bytes)); |
| char[] utf16 = new char[cb.length()]; |
| cb.get(utf16); |
| return fromCharArray(utf16, file); |
| } |
| |
| /** |
| * Returns an input source that reads from a Latin1-encoded byte array. The caller is free to |
| * subsequently mutate the array. |
| * |
| * <p>This function exists to support legacy uses of Latin1 in Bazel. Do not use Latin1 in new |
| * applications. (Consider this deprecated, without the fussy warnings.) |
| */ |
| public static ParserInput fromLatin1(byte[] bytes, String file) { |
| char[] chars = new char[bytes.length]; |
| for (int i = 0; i < bytes.length; i++) { |
| chars[i] = (char) (0xff & bytes[i]); |
| } |
| return new ParserInput(chars, file); |
| } |
| |
| /** Returns an input source that reads from the given string. */ |
| public static ParserInput fromString(String content, String file) { |
| return fromCharArray(content.toCharArray(), file); |
| } |
| |
| /** |
| * Returns an input source that reads from the given char array. The caller must not subsequently |
| * modify the array. |
| */ |
| public static ParserInput fromCharArray(char[] content, String file) { |
| return new ParserInput(content, file); |
| } |
| } |