blob: 09e7cce426480704d7963c821b0604f0154b9e55 [file] [log] [blame]
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
library _fe_analyzer_shared.scanner.recover;
import 'token.dart' show Token, TokenType;
import 'token_impl.dart' show StringToken;
import 'error_token.dart' show ErrorToken;
/// Recover from errors in [tokens]. The original sources are provided as
/// [bytes]. [lineStarts] are the beginning character offsets of lines, and
/// must be updated if recovery is performed rewriting the original source
/// code.
Token scannerRecovery(List<int> bytes, Token tokens, List<int> lineStarts) {
// Sanity check that all error tokens are prepended.
// TODO(danrubel): Remove this in a while after the dust has settled.
// Skip over prepended error tokens
Token token = tokens;
while (token is ErrorToken) {
token = token.next;
}
// Assert no error tokens in the remaining tokens
while (!token.isEof) {
if (token is ErrorToken) {
for (int count = 0; count < 3; ++count) {
Token previous = token.previous;
if (previous.isEof) break;
token = previous;
}
StringBuffer msg = new StringBuffer(
"Internal error: All error tokens should have been prepended:");
for (int count = 0; count < 7; ++count) {
if (token.isEof) break;
msg.write(' ${token.runtimeType},');
token = token.next;
}
throw msg.toString();
}
token = token.next;
}
return tokens;
}
Token synthesizeToken(int charOffset, String value, TokenType type) {
return new StringToken.fromString(type, value, charOffset);
}
Token skipToEof(Token token) {
while (!token.isEof) {
token = token.next;
}
return token;
}
String closeBraceFor(String openBrace) {
return const {
'(': ')',
'[': ']',
'{': '}',
'<': '>',
r'${': '}',
'?.[': ']',
}[openBrace];
}
String closeQuoteFor(String openQuote) {
return const {
'"': '"',
"'": "'",
'"""': '"""',
"'''": "'''",
'r"': '"',
"r'": "'",
'r"""': '"""',
"r'''": "'''",
}[openQuote];
}