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/* @internal */
namespace ts {
// Note(cyrusn): this enum is ordered from strongest match type to weakest match type.
export enum PatternMatchKind {
exact,
prefix,
substring,
camelCase
}
// Information about a match made by the pattern matcher between a candidate and the
// search pattern.
export interface PatternMatch {
// What kind of match this was. Exact matches are better than prefix matches which are
// better than substring matches which are better than CamelCase matches.
kind: PatternMatchKind;
// If this was a match where all constituent parts of the candidate and search pattern
// matched case sensitively or case insensitively. Case sensitive matches of the kind
// are better matches than insensitive matches.
isCaseSensitive: boolean;
}
// The pattern matcher maintains an internal cache of information as it is used. Therefore,
// you should not keep it around forever and should get and release the matcher appropriately
// once you no longer need it.
export interface PatternMatcher {
// Used to match a candidate against the last segment of a possibly dotted pattern. This
// is useful as a quick check to prevent having to compute a container before calling
// "getMatches".
//
// For example, if the search pattern is "ts.c.SK" and the candidate is "SyntaxKind", then
// this will return a successful match, having only tested "SK" against "SyntaxKind". At
// that point a call can be made to 'getMatches("SyntaxKind", "ts.compiler")', with the
// work to create 'ts.compiler' only being done once the first match succeeded.
getMatchForLastSegmentOfPattern(candidate: string): PatternMatch | undefined;
// Fully checks a candidate, with an dotted container, against the search pattern.
// The candidate must match the last part of the search pattern, and the dotted container
// must match the preceding segments of the pattern.
getFullMatch(candidateContainers: ReadonlyArray<string>, candidate: string): PatternMatch | undefined;
// Whether or not the pattern contained dots or not. Clients can use this to determine
// If they should call getMatches, or if getMatchesForLastSegmentOfPattern is sufficient.
patternContainsDots: boolean;
}
// First we break up the pattern given by dots. Each portion of the pattern between the
// dots is a 'Segment'. The 'Segment' contains information about the entire section of
// text between the dots, as well as information about any individual 'Words' that we
// can break the segment into. A 'Word' is simply a contiguous sequence of characters
// that can appear in a typescript identifier. So "GetKeyword" would be one word, while
// "Get Keyword" would be two words. Once we have the individual 'words', we break those
// into constituent 'character spans' of interest. For example, while 'UIElement' is one
// word, it make character spans corresponding to "U", "I" and "Element". These spans
// are then used when doing camel cased matches against candidate patterns.
interface Segment {
// Information about the entire piece of text between the dots. For example, if the
// text between the dots is 'GetKeyword', then TotalTextChunk.Text will be 'GetKeyword' and
// TotalTextChunk.CharacterSpans will correspond to 'Get', 'Keyword'.
totalTextChunk: TextChunk;
// Information about the subwords compromising the total word. For example, if the
// text between the dots is 'GetFoo KeywordBar', then the subwords will be 'GetFoo'
// and 'KeywordBar'. Those individual words will have CharacterSpans of ('Get' and
// 'Foo') and('Keyword' and 'Bar') respectively.
subWordTextChunks: TextChunk[];
}
// Information about a chunk of text from the pattern. The chunk is a piece of text, with
// cached information about the character spans within in. Character spans are used for
// camel case matching.
interface TextChunk {
// The text of the chunk. This should be a contiguous sequence of character that could
// occur in a symbol name.
text: string;
// The text of a chunk in lower case. Cached because it is needed often to check for
// case insensitive matches.
textLowerCase: string;
// Whether or not this chunk is entirely lowercase. We have different rules when searching
// for something entirely lowercase or not.
isLowerCase: boolean;
// The spans in this text chunk that we think are of interest and should be matched
// independently. For example, if the chunk is for "UIElement" the the spans of interest
// correspond to "U", "I" and "Element". If "UIElement" isn't found as an exact, prefix.
// or substring match, then the character spans will be used to attempt a camel case match.
characterSpans: TextSpan[];
}
function createPatternMatch(kind: PatternMatchKind, isCaseSensitive: boolean): PatternMatch {
return {
kind,
isCaseSensitive
};
}
export function createPatternMatcher(pattern: string): PatternMatcher | undefined {
// We'll often see the same candidate string many times when searching (For example, when
// we see the name of a module that is used everywhere, or the name of an overload). As
// such, we cache the information we compute about the candidate for the life of this
// pattern matcher so we don't have to compute it multiple times.
const stringToWordSpans = createMap<TextSpan[]>();
const dotSeparatedSegments = pattern.trim().split(".").map(p => createSegment(p.trim()));
// A segment is considered invalid if we couldn't find any words in it.
if (dotSeparatedSegments.some(segment => !segment.subWordTextChunks.length)) return undefined;
return {
getFullMatch: (containers, candidate) => getFullMatch(containers, candidate, dotSeparatedSegments, stringToWordSpans),
getMatchForLastSegmentOfPattern: candidate => matchSegment(candidate, last(dotSeparatedSegments), stringToWordSpans),
patternContainsDots: dotSeparatedSegments.length > 1
};
}
function getFullMatch(candidateContainers: ReadonlyArray<string>, candidate: string, dotSeparatedSegments: ReadonlyArray<Segment>, stringToWordSpans: Map<TextSpan[]>): PatternMatch | undefined {
// First, check that the last part of the dot separated pattern matches the name of the
// candidate. If not, then there's no point in proceeding and doing the more
// expensive work.
const candidateMatch = matchSegment(candidate, last(dotSeparatedSegments), stringToWordSpans);
if (!candidateMatch) {
return undefined;
}
// -1 because the last part was checked against the name, and only the rest
// of the parts are checked against the container.
if (dotSeparatedSegments.length - 1 > candidateContainers.length) {
// There weren't enough container parts to match against the pattern parts.
// So this definitely doesn't match.
return undefined;
}
let bestMatch: PatternMatch | undefined;
for (let i = dotSeparatedSegments.length - 2, j = candidateContainers.length - 1;
i >= 0;
i -= 1, j -= 1) {
bestMatch = betterMatch(bestMatch, matchSegment(candidateContainers[j], dotSeparatedSegments[i], stringToWordSpans));
}
return bestMatch;
}
function getWordSpans(word: string, stringToWordSpans: Map<TextSpan[]>): TextSpan[] {
let spans = stringToWordSpans.get(word);
if (!spans) {
stringToWordSpans.set(word, spans = breakIntoWordSpans(word));
}
return spans;
}
function matchTextChunk(candidate: string, chunk: TextChunk, stringToWordSpans: Map<TextSpan[]>): PatternMatch | undefined {
const index = indexOfIgnoringCase(candidate, chunk.textLowerCase);
if (index === 0) {
// a) Check if the word is a prefix of the candidate, in a case insensitive or
// sensitive manner. If it does, return that there was an exact match if the word and candidate are the same length, else a prefix match.
return createPatternMatch(chunk.text.length === candidate.length ? PatternMatchKind.exact : PatternMatchKind.prefix, /*isCaseSensitive:*/ startsWith(candidate, chunk.text));
}
if (chunk.isLowerCase) {
if (index === -1) return undefined;
// b) If the part is entirely lowercase, then check if it is contained anywhere in the
// candidate in a case insensitive manner. If so, return that there was a substring
// match.
//
// Note: We only have a substring match if the lowercase part is prefix match of some
// word part. That way we don't match something like 'Class' when the user types 'a'.
// But we would match 'FooAttribute' (since 'Attribute' starts with 'a').
const wordSpans = getWordSpans(candidate, stringToWordSpans);
for (const span of wordSpans) {
if (partStartsWith(candidate, span, chunk.text, /*ignoreCase:*/ true)) {
return createPatternMatch(PatternMatchKind.substring, /*isCaseSensitive:*/ partStartsWith(candidate, span, chunk.text, /*ignoreCase:*/ false));
}
}
// c) Is the pattern a substring of the candidate starting on one of the candidate's word boundaries?
// We could check every character boundary start of the candidate for the pattern. However, that's
// an m * n operation in the wost case. Instead, find the first instance of the pattern
// substring, and see if it starts on a capital letter. It seems unlikely that the user will try to
// filter the list based on a substring that starts on a capital letter and also with a lowercase one.
// (Pattern: fogbar, Candidate: quuxfogbarFogBar).
if (chunk.text.length < candidate.length && isUpperCaseLetter(candidate.charCodeAt(index))) {
return createPatternMatch(PatternMatchKind.substring, /*isCaseSensitive:*/ false);
}
}
else {
// d) If the part was not entirely lowercase, then check if it is contained in the
// candidate in a case *sensitive* manner. If so, return that there was a substring
// match.
if (candidate.indexOf(chunk.text) > 0) {
return createPatternMatch(PatternMatchKind.substring, /*isCaseSensitive:*/ true);
}
// e) If the part was not entirely lowercase, then attempt a camel cased match as well.
if (chunk.characterSpans.length > 0) {
const candidateParts = getWordSpans(candidate, stringToWordSpans);
const isCaseSensitive = tryCamelCaseMatch(candidate, candidateParts, chunk, /*ignoreCase:*/ false) ? true
: tryCamelCaseMatch(candidate, candidateParts, chunk, /*ignoreCase:*/ true) ? false : undefined;
if (isCaseSensitive !== undefined) {
return createPatternMatch(PatternMatchKind.camelCase, isCaseSensitive);
}
}
}
}
function matchSegment(candidate: string, segment: Segment, stringToWordSpans: Map<TextSpan[]>): PatternMatch | undefined {
// First check if the segment matches as is. This is also useful if the segment contains
// characters we would normally strip when splitting into parts that we also may want to
// match in the candidate. For example if the segment is "@int" and the candidate is
// "@int", then that will show up as an exact match here.
//
// Note: if the segment contains a space or an asterisk then we must assume that it's a
// multi-word segment.
if (every(segment.totalTextChunk.text, ch => ch !== CharacterCodes.space && ch !== CharacterCodes.asterisk)) {
const match = matchTextChunk(candidate, segment.totalTextChunk, stringToWordSpans);
if (match) return match;
}
// The logic for pattern matching is now as follows:
//
// 1) Break the segment passed in into words. Breaking is rather simple and a
// good way to think about it that if gives you all the individual alphanumeric words
// of the pattern.
//
// 2) For each word try to match the word against the candidate value.
//
// 3) Matching is as follows:
//
// a) Check if the word is a prefix of the candidate, in a case insensitive or
// sensitive manner. If it does, return that there was an exact match if the word and candidate are the same length, else a prefix match.
//
// If the word is entirely lowercase:
// b) Then check if it is contained anywhere in the
// candidate in a case insensitive manner. If so, return that there was a substring
// match.
//
// Note: We only have a substring match if the lowercase part is prefix match of
// some word part. That way we don't match something like 'Class' when the user
// types 'a'. But we would match 'FooAttribute' (since 'Attribute' starts with
// 'a').
//
// c) The word is all lower case. Is it a case insensitive substring of the candidate starting
// on a part boundary of the candidate?
//
// Else:
// d) If the word was not entirely lowercase, then check if it is contained in the
// candidate in a case *sensitive* manner. If so, return that there was a substring
// match.
//
// e) If the word was not entirely lowercase, then attempt a camel cased match as
// well.
//
// Only if all words have some sort of match is the pattern considered matched.
const subWordTextChunks = segment.subWordTextChunks;
let bestMatch: PatternMatch | undefined;
for (const subWordTextChunk of subWordTextChunks) {
bestMatch = betterMatch(bestMatch, matchTextChunk(candidate, subWordTextChunk, stringToWordSpans));
}
return bestMatch;
}
function betterMatch(a: PatternMatch | undefined, b: PatternMatch | undefined): PatternMatch | undefined {
return min(a, b, compareMatches);
}
function compareMatches(a: PatternMatch | undefined, b: PatternMatch | undefined): Comparison {
return a === undefined ? Comparison.GreaterThan : b === undefined ? Comparison.LessThan
: compareValues(a.kind, b.kind) || compareBooleans(!a.isCaseSensitive, !b.isCaseSensitive);
}
function partStartsWith(candidate: string, candidateSpan: TextSpan, pattern: string, ignoreCase: boolean, patternSpan: TextSpan = { start: 0, length: pattern.length }): boolean {
return patternSpan.length <= candidateSpan.length // If pattern part is longer than the candidate part there can never be a match.
&& everyInRange(0, patternSpan.length, i => equalChars(pattern.charCodeAt(patternSpan.start + i), candidate.charCodeAt(candidateSpan.start + i), ignoreCase));
}
function equalChars(ch1: number, ch2: number, ignoreCase: boolean): boolean {
return ignoreCase ? toLowerCase(ch1) === toLowerCase(ch2) : ch1 === ch2;
}
function tryCamelCaseMatch(candidate: string, candidateParts: TextSpan[], chunk: TextChunk, ignoreCase: boolean): boolean {
const chunkCharacterSpans = chunk.characterSpans;
// Note: we may have more pattern parts than candidate parts. This is because multiple
// pattern parts may match a candidate part. For example "SiUI" against "SimpleUI".
// We'll have 3 pattern parts Si/U/I against two candidate parts Simple/UI. However, U
// and I will both match in UI.
let currentCandidate = 0;
let currentChunkSpan = 0;
let firstMatch: number | undefined;
let contiguous: boolean | undefined;
while (true) {
// Let's consider our termination cases
if (currentChunkSpan === chunkCharacterSpans.length) {
return true;
}
else if (currentCandidate === candidateParts.length) {
// No match, since we still have more of the pattern to hit
return false;
}
let candidatePart = candidateParts[currentCandidate];
let gotOneMatchThisCandidate = false;
// Consider the case of matching SiUI against SimpleUIElement. The candidate parts
// will be Simple/UI/Element, and the pattern parts will be Si/U/I. We'll match 'Si'
// against 'Simple' first. Then we'll match 'U' against 'UI'. However, we want to
// still keep matching pattern parts against that candidate part.
for (; currentChunkSpan < chunkCharacterSpans.length; currentChunkSpan++) {
const chunkCharacterSpan = chunkCharacterSpans[currentChunkSpan];
if (gotOneMatchThisCandidate) {
// We've already gotten one pattern part match in this candidate. We will
// only continue trying to consumer pattern parts if the last part and this
// part are both upper case.
if (!isUpperCaseLetter(chunk.text.charCodeAt(chunkCharacterSpans[currentChunkSpan - 1].start)) ||
!isUpperCaseLetter(chunk.text.charCodeAt(chunkCharacterSpans[currentChunkSpan].start))) {
break;
}
}
if (!partStartsWith(candidate, candidatePart, chunk.text, ignoreCase, chunkCharacterSpan)) {
break;
}
gotOneMatchThisCandidate = true;
firstMatch = firstMatch === undefined ? currentCandidate : firstMatch;
// If we were contiguous, then keep that value. If we weren't, then keep that
// value. If we don't know, then set the value to 'true' as an initial match is
// obviously contiguous.
contiguous = contiguous === undefined ? true : contiguous;
candidatePart = createTextSpan(candidatePart.start + chunkCharacterSpan.length, candidatePart.length - chunkCharacterSpan.length);
}
// Check if we matched anything at all. If we didn't, then we need to unset the
// contiguous bit if we currently had it set.
// If we haven't set the bit yet, then that means we haven't matched anything so
// far, and we don't want to change that.
if (!gotOneMatchThisCandidate && contiguous !== undefined) {
contiguous = false;
}
// Move onto the next candidate.
currentCandidate++;
}
}
function createSegment(text: string): Segment {
return {
totalTextChunk: createTextChunk(text),
subWordTextChunks: breakPatternIntoTextChunks(text)
};
}
function isUpperCaseLetter(ch: number) {
// Fast check for the ascii range.
if (ch >= CharacterCodes.A && ch <= CharacterCodes.Z) {
return true;
}
if (ch < CharacterCodes.maxAsciiCharacter || !isUnicodeIdentifierStart(ch, ScriptTarget.Latest)) {
return false;
}
// TODO: find a way to determine this for any unicode characters in a
// non-allocating manner.
const str = String.fromCharCode(ch);
return str === str.toUpperCase();
}
function isLowerCaseLetter(ch: number) {
// Fast check for the ascii range.
if (ch >= CharacterCodes.a && ch <= CharacterCodes.z) {
return true;
}
if (ch < CharacterCodes.maxAsciiCharacter || !isUnicodeIdentifierStart(ch, ScriptTarget.Latest)) {
return false;
}
// TODO: find a way to determine this for any unicode characters in a
// non-allocating manner.
const str = String.fromCharCode(ch);
return str === str.toLowerCase();
}
// Assumes 'value' is already lowercase.
function indexOfIgnoringCase(str: string, value: string): number {
const n = str.length - value.length;
for (let start = 0; start <= n; start++) {
if (every(value, (valueChar, i) => toLowerCase(str.charCodeAt(i + start)) === valueChar)) {
return start;
}
}
return -1;
}
function toLowerCase(ch: number): number {
// Fast convert for the ascii range.
if (ch >= CharacterCodes.A && ch <= CharacterCodes.Z) {
return CharacterCodes.a + (ch - CharacterCodes.A);
}
if (ch < CharacterCodes.maxAsciiCharacter) {
return ch;
}
// TODO: find a way to compute this for any unicode characters in a
// non-allocating manner.
return String.fromCharCode(ch).toLowerCase().charCodeAt(0);
}
function isDigit(ch: number) {
// TODO(cyrusn): Find a way to support this for unicode digits.
return ch >= CharacterCodes._0 && ch <= CharacterCodes._9;
}
function isWordChar(ch: number) {
return isUpperCaseLetter(ch) || isLowerCaseLetter(ch) || isDigit(ch) || ch === CharacterCodes._ || ch === CharacterCodes.$;
}
function breakPatternIntoTextChunks(pattern: string): TextChunk[] {
const result: TextChunk[] = [];
let wordStart = 0;
let wordLength = 0;
for (let i = 0; i < pattern.length; i++) {
const ch = pattern.charCodeAt(i);
if (isWordChar(ch)) {
if (wordLength === 0) {
wordStart = i;
}
wordLength++;
}
else {
if (wordLength > 0) {
result.push(createTextChunk(pattern.substr(wordStart, wordLength)));
wordLength = 0;
}
}
}
if (wordLength > 0) {
result.push(createTextChunk(pattern.substr(wordStart, wordLength)));
}
return result;
}
function createTextChunk(text: string): TextChunk {
const textLowerCase = text.toLowerCase();
return {
text,
textLowerCase,
isLowerCase: text === textLowerCase,
characterSpans: breakIntoCharacterSpans(text)
};
}
export function breakIntoCharacterSpans(identifier: string): TextSpan[] {
return breakIntoSpans(identifier, /*word:*/ false);
}
export function breakIntoWordSpans(identifier: string): TextSpan[] {
return breakIntoSpans(identifier, /*word:*/ true);
}
function breakIntoSpans(identifier: string, word: boolean): TextSpan[] {
const result: TextSpan[] = [];
let wordStart = 0;
for (let i = 1; i < identifier.length; i++) {
const lastIsDigit = isDigit(identifier.charCodeAt(i - 1));
const currentIsDigit = isDigit(identifier.charCodeAt(i));
const hasTransitionFromLowerToUpper = transitionFromLowerToUpper(identifier, word, i);
const hasTransitionFromUpperToLower = word && transitionFromUpperToLower(identifier, i, wordStart);
if (charIsPunctuation(identifier.charCodeAt(i - 1)) ||
charIsPunctuation(identifier.charCodeAt(i)) ||
lastIsDigit !== currentIsDigit ||
hasTransitionFromLowerToUpper ||
hasTransitionFromUpperToLower) {
if (!isAllPunctuation(identifier, wordStart, i)) {
result.push(createTextSpan(wordStart, i - wordStart));
}
wordStart = i;
}
}
if (!isAllPunctuation(identifier, wordStart, identifier.length)) {
result.push(createTextSpan(wordStart, identifier.length - wordStart));
}
return result;
}
function charIsPunctuation(ch: number) {
switch (ch) {
case CharacterCodes.exclamation:
case CharacterCodes.doubleQuote:
case CharacterCodes.hash:
case CharacterCodes.percent:
case CharacterCodes.ampersand:
case CharacterCodes.singleQuote:
case CharacterCodes.openParen:
case CharacterCodes.closeParen:
case CharacterCodes.asterisk:
case CharacterCodes.comma:
case CharacterCodes.minus:
case CharacterCodes.dot:
case CharacterCodes.slash:
case CharacterCodes.colon:
case CharacterCodes.semicolon:
case CharacterCodes.question:
case CharacterCodes.at:
case CharacterCodes.openBracket:
case CharacterCodes.backslash:
case CharacterCodes.closeBracket:
case CharacterCodes._:
case CharacterCodes.openBrace:
case CharacterCodes.closeBrace:
return true;
}
return false;
}
function isAllPunctuation(identifier: string, start: number, end: number): boolean {
return every(identifier, ch => charIsPunctuation(ch) && ch !== CharacterCodes._, start, end);
}
function transitionFromUpperToLower(identifier: string, index: number, wordStart: number): boolean {
// Cases this supports:
// 1) IDisposable -> I, Disposable
// 2) UIElement -> UI, Element
// 3) HTMLDocument -> HTML, Document
//
// etc.
// We have a transition from an upper to a lower letter here. But we only
// want to break if all the letters that preceded are uppercase. i.e. if we
// have "Foo" we don't want to break that into "F, oo". But if we have
// "IFoo" or "UIFoo", then we want to break that into "I, Foo" and "UI,
// Foo". i.e. the last uppercase letter belongs to the lowercase letters
// that follows. Note: this will make the following not split properly:
// "HELLOthere". However, these sorts of names do not show up in .Net
// programs.
return index !== wordStart
&& index + 1 < identifier.length
&& isUpperCaseLetter(identifier.charCodeAt(index))
&& isLowerCaseLetter(identifier.charCodeAt(index + 1))
&& every(identifier, isUpperCaseLetter, wordStart, index);
}
function transitionFromLowerToUpper(identifier: string, word: boolean, index: number): boolean {
const lastIsUpper = isUpperCaseLetter(identifier.charCodeAt(index - 1));
const currentIsUpper = isUpperCaseLetter(identifier.charCodeAt(index));
// See if the casing indicates we're starting a new word. Note: if we're breaking on
// words, then just seeing an upper case character isn't enough. Instead, it has to
// be uppercase and the previous character can't be uppercase.
//
// For example, breaking "AddMetadata" on words would make: Add Metadata
//
// on characters would be: A dd M etadata
//
// Break "AM" on words would be: AM
//
// on characters would be: A M
//
// We break the search string on characters. But we break the symbol name on words.
return currentIsUpper && (!word || !lastIsUpper);
}
function everyInRange(start: number, end: number, pred: (n: number) => boolean): boolean {
for (let i = start; i < end; i++) {
if (!pred(i)) {
return false;
}
}
return true;
}
function every(s: string, pred: (ch: number, index: number) => boolean, start = 0, end = s.length): boolean {
return everyInRange(start, end, i => pred(s.charCodeAt(i), i));
}
}
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