/*---------------------------------------------------------------------------------------------
*  Copyright (c) Microsoft Corporation. All rights reserved.
*  Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
(function (factory) {
    if (typeof module === "object" && typeof module.exports === "object") {
        var v = factory(require, exports);
        if (v !== undefined) module.exports = v;
    }
    else if (typeof define === "function" && define.amd) {
        define(["require", "exports"], factory);
    }
})(function (require, exports) {
    "use strict";
    Object.defineProperty(exports, "__esModule", { value: true });
    exports.startsWith = startsWith;
    exports.endsWith = endsWith;
    exports.convertSimple2RegExpPattern = convertSimple2RegExpPattern;
    exports.repeat = repeat;
    exports.extendedRegExp = extendedRegExp;
    exports.stringLength = stringLength;
    function startsWith(haystack, needle) {
        if (haystack.length < needle.length) {
            return false;
        }
        for (let i = 0; i < needle.length; i++) {
            if (haystack[i] !== needle[i]) {
                return false;
            }
        }
        return true;
    }
    /**
     * Determines if haystack ends with needle.
     */
    function endsWith(haystack, needle) {
        const diff = haystack.length - needle.length;
        if (diff > 0) {
            return haystack.lastIndexOf(needle) === diff;
        }
        else if (diff === 0) {
            return haystack === needle;
        }
        else {
            return false;
        }
    }
    function convertSimple2RegExpPattern(pattern) {
        return pattern.replace(/[\-\\\{\}\+\?\|\^\$\.\,\[\]\(\)\#\s]/g, '\\$&').replace(/[\*]/g, '.*');
    }
    function repeat(value, count) {
        let s = '';
        while (count > 0) {
            if ((count & 1) === 1) {
                s += value;
            }
            value += value;
            count = count >>> 1;
        }
        return s;
    }
    function extendedRegExp(pattern) {
        let flags = '';
        if (startsWith(pattern, '(?i)')) {
            pattern = pattern.substring(4);
            flags = 'i';
        }
        try {
            return new RegExp(pattern, flags + 'u');
        }
        catch (e) {
            // could be an exception due to the 'u ' flag
            try {
                return new RegExp(pattern, flags);
            }
            catch (e) {
                // invalid pattern
                return undefined;
            }
        }
    }
    // from https://tanishiking.github.io/posts/count-unicode-codepoint/#work-hard-with-for-statements
    function stringLength(str) {
        let count = 0;
        for (let i = 0; i < str.length; i++) {
            count++;
            // obtain the i-th 16-bit
            const code = str.charCodeAt(i);
            if (0xD800 <= code && code <= 0xDBFF) {
                // if the i-th 16bit is an upper surrogate
                // skip the next 16 bits (lower surrogate)
                i++;
            }
        }
        return count;
    }
});
