node_modules/@angular/cdk/schematics/update-tool/utils/line-mappings.js

"use strict";
/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
Object.defineProperty(exports, "__esModule", { value: true });
/*
 * Line mapping utilities which can be used to retrieve line and character based
 * on an absolute character position in a given file. This functionality is similar
 * to TypeScript's "ts.getLineAndCharacterFromPosition" utility, but we cannot leverage
 * their logic for line mappings as it's internal and we need to generate line mappings
 * for non-TypeScript files such as HTML templates or stylesheets.
 *
 * Line and character can be retrieved by splitting a given source text based on
 * line breaks into line start entries. Later when a specific position is requested,
 * the closest line-start position is determined based on the given position.
 */
const LF_CHAR = 10;
const CR_CHAR = 13;
const LINE_SEP_CHAR = 8232;
const PARAGRAPH_CHAR = 8233;
/** Gets the line and character for the given position from the line starts map. */
function getLineAndCharacterFromPosition(lineStartsMap, position) {
    const lineIndex = findClosestLineStartPosition(lineStartsMap, position);
    return { character: position - lineStartsMap[lineIndex], line: lineIndex };
}
exports.getLineAndCharacterFromPosition = getLineAndCharacterFromPosition;
/**
 * Computes the line start map of the given text. This can be used in order to
 * retrieve the line and character of a given text position index.
 */
function computeLineStartsMap(text) {
    const result = [0];
    let pos = 0;
    while (pos < text.length) {
        const char = text.charCodeAt(pos++);
        // Handles the "CRLF" line break. In that case we peek the character
        // after the "CR" and check if it is a line feed.
        if (char === CR_CHAR) {
            if (text.charCodeAt(pos) === LF_CHAR) {
                pos++;
            }
            result.push(pos);
        }
        else if (char === LF_CHAR || char === LINE_SEP_CHAR || char === PARAGRAPH_CHAR) {
            result.push(pos);
        }
    }
    result.push(pos);
    return result;
}
exports.computeLineStartsMap = computeLineStartsMap;
/** Finds the closest line start for the given position. */
function findClosestLineStartPosition(linesMap, position, low = 0, high = linesMap.length - 1) {
    while (low <= high) {
        const pivotIndex = Math.floor((low + high) / 2);
        const pivotEl = linesMap[pivotIndex];
        if (pivotEl === position) {
            return pivotIndex;
        }
        else if (position > pivotEl) {
            low = pivotIndex + 1;
        }
        else {
            high = pivotIndex - 1;
        }
    }
    // In case there was no exact match, return the closest "lower" line index. We also
    // subtract the index by one because want the index of the previous line start.
    return low - 1;
}
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