| Index: mojo/public/dart/third_party/analyzer/lib/src/generated/incremental_scanner.dart
|
| diff --git a/mojo/public/dart/third_party/analyzer/lib/src/generated/incremental_scanner.dart b/mojo/public/dart/third_party/analyzer/lib/src/generated/incremental_scanner.dart
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..a2e4daf794d5eb12eefa8c59443b798ee8e0edda
|
| --- /dev/null
|
| +++ b/mojo/public/dart/third_party/analyzer/lib/src/generated/incremental_scanner.dart
|
| @@ -0,0 +1,248 @@
|
| +// Copyright (c) 2014, 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 engine.incremental_scanner;
|
| +
|
| +import "dart:math" as math;
|
| +
|
| +import 'package:analyzer/src/generated/engine.dart';
|
| +
|
| +import 'error.dart';
|
| +import 'scanner.dart';
|
| +import 'source.dart';
|
| +import 'utilities_collection.dart' show TokenMap;
|
| +
|
| +/**
|
| + * An `IncrementalScanner` is a scanner that scans a subset of a string and
|
| + * inserts the resulting tokens into the middle of an existing token stream.
|
| + */
|
| +class IncrementalScanner {
|
| + /**
|
| + * The source being scanned.
|
| + */
|
| + final Source source;
|
| +
|
| + /**
|
| + * The reader used to access the characters in the source.
|
| + */
|
| + final CharacterReader reader;
|
| +
|
| + /**
|
| + * The error listener that will be informed of any errors that are found
|
| + * during the scan.
|
| + *
|
| + * TODO(brianwilkerson) Replace this with a list of errors so that we can
|
| + * update the errors.
|
| + */
|
| + final AnalysisErrorListener errorListener;
|
| +
|
| + final AnalysisOptions _options;
|
| +
|
| + /**
|
| + * A map from tokens that were copied to the copies of the tokens.
|
| + */
|
| + TokenMap _tokenMap = new TokenMap();
|
| +
|
| + /**
|
| + * The token immediately to the left of the range of tokens that were
|
| + * modified.
|
| + */
|
| + Token leftToken;
|
| +
|
| + /**
|
| + * The token immediately to the right of the range of tokens that were
|
| + * modified.
|
| + */
|
| + Token rightToken;
|
| +
|
| + /**
|
| + * A flag indicating whether there were any non-comment tokens changed (other
|
| + * than having their position updated) as a result of the modification.
|
| + */
|
| + bool hasNonWhitespaceChange = false;
|
| +
|
| + /**
|
| + * Initialize a newly created scanner to scan characters within the given
|
| + * [source]. The content of the source can be read using the given [reader].
|
| + * Any errors that are found will be reported to the given [errorListener].
|
| + * [_options] will determine how scanning is to be performed.
|
| + */
|
| + IncrementalScanner(
|
| + this.source, this.reader, this.errorListener, this._options);
|
| +
|
| + /**
|
| + * Return a map from tokens that were copied to the copies of the tokens.
|
| + *
|
| + * @return a map from tokens that were copied to the copies of the tokens
|
| + */
|
| + TokenMap get tokenMap => _tokenMap;
|
| +
|
| + /**
|
| + * Given the [stream] of tokens scanned from the original source, the modified
|
| + * source (the result of replacing one contiguous range of characters with
|
| + * another string of characters), and a specification of the modification that
|
| + * was made, update the token stream to reflect the modified source. Return
|
| + * the first token in the updated token stream.
|
| + *
|
| + * The [stream] is expected to be the first non-EOF token in the token stream.
|
| + *
|
| + * The modification is specified by the [index] of the first character in both
|
| + * the original and modified source that was affected by the modification, the
|
| + * number of characters removed from the original source (the [removedLength])
|
| + * and the number of characters added to the modified source (the
|
| + * [insertedLength]).
|
| + */
|
| + Token rescan(Token stream, int index, int removedLength, int insertedLength) {
|
| + Token leftEof = stream.previous;
|
| + //
|
| + // Compute the delta between the character index of characters after the
|
| + // modified region in the original source and the index of the corresponding
|
| + // character in the modified source.
|
| + //
|
| + int delta = insertedLength - removedLength;
|
| + //
|
| + // Skip past the tokens whose end is less than the replacement start. (If
|
| + // the replacement start is equal to the end of an existing token, then it
|
| + // means that the existing token might have been modified, so we need to
|
| + // rescan it.)
|
| + //
|
| + while (stream.type != TokenType.EOF && stream.end < index) {
|
| + _tokenMap.put(stream, stream);
|
| + stream = stream.next;
|
| + }
|
| + Token oldFirst = stream;
|
| + Token oldLeftToken = stream.previous;
|
| + leftToken = oldLeftToken;
|
| + //
|
| + // Skip past tokens until we find a token whose offset is greater than the
|
| + // end of the removed region. (If the end of the removed region is equal to
|
| + // the beginning of an existing token, then it means that the existing token
|
| + // might have been modified, so we need to rescan it.)
|
| + //
|
| + int removedEnd = index + (removedLength == 0 ? 0 : removedLength - 1);
|
| + while (stream.type != TokenType.EOF && stream.offset <= removedEnd) {
|
| + stream = stream.next;
|
| + }
|
| + //
|
| + // Figure out which region of characters actually needs to be re-scanned.
|
| + //
|
| + Token oldLast;
|
| + Token oldRightToken;
|
| + if (stream.type != TokenType.EOF && removedEnd + 1 == stream.offset) {
|
| + oldLast = stream;
|
| + stream = stream.next;
|
| + oldRightToken = stream;
|
| + } else {
|
| + oldLast = stream.previous;
|
| + oldRightToken = stream;
|
| + }
|
| + //
|
| + // Compute the range of characters that are known to need to be rescanned.
|
| + // If the index is within an existing token, then we need to start at the
|
| + // beginning of the token.
|
| + //
|
| + int scanStart = math.max(oldLeftToken.end, 0);
|
| + int scanEnd = oldRightToken.offset + delta;
|
| + //
|
| + // Rescan the characters that need to be rescanned.
|
| + //
|
| + Token replacementStart = _scanRange(scanStart, scanEnd);
|
| + oldLeftToken.setNext(replacementStart);
|
| + Token replacementEnd = _findEof(replacementStart).previous;
|
| + replacementEnd.setNext(stream);
|
| + //
|
| + // Apply the delta to the tokens after the last new token.
|
| + //
|
| + _updateOffsets(stream, delta);
|
| + rightToken = stream;
|
| + //
|
| + // If the index is immediately after an existing token and the inserted
|
| + // characters did not change that original token, then adjust the leftToken
|
| + // to be the next token. For example, in "a; c;" --> "a;b c;", the leftToken
|
| + // was ";", but this code advances it to "b" since "b" is the first new
|
| + // token.
|
| + //
|
| + Token newFirst = leftToken.next;
|
| + while (!identical(newFirst, rightToken) &&
|
| + !identical(oldFirst, oldRightToken) &&
|
| + newFirst.type != TokenType.EOF &&
|
| + _equalTokens(oldFirst, newFirst)) {
|
| + _tokenMap.put(oldFirst, newFirst);
|
| + oldLeftToken = oldFirst;
|
| + oldFirst = oldFirst.next;
|
| + leftToken = newFirst;
|
| + newFirst = newFirst.next;
|
| + }
|
| + Token newLast = rightToken.previous;
|
| + while (!identical(newLast, leftToken) &&
|
| + !identical(oldLast, oldLeftToken) &&
|
| + newLast.type != TokenType.EOF &&
|
| + _equalTokens(oldLast, newLast)) {
|
| + _tokenMap.put(oldLast, newLast);
|
| + oldRightToken = oldLast;
|
| + oldLast = oldLast.previous;
|
| + rightToken = newLast;
|
| + newLast = newLast.previous;
|
| + }
|
| + hasNonWhitespaceChange = !identical(leftToken.next, rightToken) ||
|
| + !identical(oldLeftToken.next, oldRightToken);
|
| + //
|
| + // TODO(brianwilkerson) Begin tokens are not getting associated with the
|
| + // corresponding end tokens (because the end tokens have not been copied
|
| + // when we're copying the begin tokens). This could have implications for
|
| + // parsing.
|
| + // TODO(brianwilkerson) Update the lineInfo.
|
| + //
|
| + return leftEof.next;
|
| + }
|
| +
|
| + /**
|
| + * Return `true` if the [oldToken] and the [newToken] are equal to each other.
|
| + * For the purposes of the incremental scanner, two tokens are equal if they
|
| + * have the same type and lexeme.
|
| + */
|
| + bool _equalTokens(Token oldToken, Token newToken) =>
|
| + oldToken.type == newToken.type &&
|
| + oldToken.length == newToken.length &&
|
| + oldToken.lexeme == newToken.lexeme;
|
| +
|
| + /**
|
| + * Given a [token], return the EOF token that follows the token.
|
| + */
|
| + Token _findEof(Token token) {
|
| + while (token.type != TokenType.EOF) {
|
| + token = token.next;
|
| + }
|
| + return token;
|
| + }
|
| +
|
| + /**
|
| + * Scan the token between the [start] (inclusive) and [end] (exclusive)
|
| + * offsets.
|
| + */
|
| + Token _scanRange(int start, int end) {
|
| + Scanner scanner = new Scanner(
|
| + source, new CharacterRangeReader(reader, start, end), errorListener);
|
| + return scanner.tokenize();
|
| + }
|
| +
|
| + /**
|
| + * Update the offsets of every token from the given [token] to the end of the
|
| + * stream by adding the given [delta].
|
| + */
|
| + void _updateOffsets(Token token, int delta) {
|
| + while (token.type != TokenType.EOF) {
|
| + _tokenMap.put(token, token);
|
| + token.offset += delta;
|
| + Token comment = token.precedingComments;
|
| + while (comment != null) {
|
| + comment.offset += delta;
|
| + comment = comment.next;
|
| + }
|
| + token = token.next;
|
| + }
|
| + _tokenMap.put(token, token);
|
| + token.offset += delta;
|
| + }
|
| +}
|
|
|