cspell/src/util/repMap.ts

A Spelling Checker for Code!

export type ReplaceEntry = [string, string];

export type ReplaceMap = ReplaceEntry[];

export type ReplaceMapper = (src: string) => string;

export function createMapper(repMap: ReplaceMap): ReplaceMapper {
    const filteredMap = repMap
        .filter(([match, _]) => !!match);
    if (!filteredMap.length) {
        return a => a;
    }
    const regExStr = filteredMap
        .map(([from, _]) => from)
        // make sure it compiles into a regex
        .map(s => {
            try {
                // fix up any nested ()
                const r = s.match(/\(/) ? s.replace(/\((?=.*\))/g, '(?:').replace(/\(\?:\?/g, '(?') : s;
                new RegExp(r);
                s = r;
            } catch (err) {
                return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
            }
            return s;
        })
        .map(s => `(${s})`)
        .join('|');

    const regEx = new RegExp(regExStr, 'g');
    const values = repMap
        .filter(([match, _]) => !!match)
        .map(([_, into]) => into);

    function resolve(m: string, ...matches: any[]) {
        const index = matches.findIndex(a => !!a);
        return 0 <= index && index < values.length ? values[index] : m;
    }

    return function(s: string) {
        return s.replace(regEx, resolve);
    };
}