Function charcomp

api/diffview.ts:407–769

(lineA:string, lineB:string)

                // this is the character comparison logic that performs the 'largest common
                // subsequence' between two lines of code
                charcomp = function diffview_report_charcomp(lineA:string, lineB:string): [string, string]{
                    let b: number = 0,
                        currentdiff = [],
                        dataMinLength: number = 0,
                        dataA: string[] = [],
                        dataB: string[] = [];
                    const cleanedA: string = (options.diff_format === "text")
                            ? lineA
                            : lineA
                                .replace(/ /g, " ")
                                .replace(/ /g, " ")
                                .replace(/&lt;/g, "<")
                                .replace(/&gt;/g, ">")
                                .replace(/\$#lt;/g, "<")
                                .replace(/\$#gt;/g, ">")
                                .replace(/&amp;/g, "&"),
                        cleanedB: string = (options.diff_format === "text")
                            ? lineB
                            : lineB
                                .replace(/&#160;/g, " ")
                                .replace(/&nbsp;/g, " ")
                                .replace(/&lt;/g, "<")
                                .replace(/&gt;/g, ">")
                                .replace(/\$#lt;/g, "<")
                                .replace(/\$#gt;/g, ">")
                                .replace(/&amp;/g, "&"),
                        regStart: RegExp = (/_pdiffdiff\u005f/g),
                        regEnd: RegExp = (/_epdiffdiff\u005f/g),
                        strStart: string = "_pdiffdiff\u005f",
                        strEnd: string = "_epdiffdiff\u005f",
                        tabdiff: [string, string, string, string] = (function diffview_report_charcomp_tabdiff(): [string, string, string, string]{
                            let tabMatchA: string = "",
                                tabMatchB: string = "",
                                splitA: string = "",
                                splitB: string = "",
                                matchListA: string[] | null = cleanedA.match(tabFix),
                                matchListB: string[] | null = cleanedB.match(tabFix);
                            if (matchListA === null || matchListB === null || (matchListA[0] === "" && matchListA.length === 1) || (matchListB[0] === "" && matchListB.length === 1)) {
                                return ["", "", cleanedA, cleanedB];
                            }
                            tabMatchA = matchListA[0];
                            tabMatchB = matchListB[0];
                            splitA = cleanedA.split(tabMatchA)[1];
                            splitB = cleanedB.split(tabMatchB)[1];
                            if (tabMatchA.length > tabMatchB.length) {
                                tabMatchA = tabMatchA.slice(0, tabMatchB.length) + strStart + tabMatchA.slice(tabMatchB.length) + strEnd;
                            } else {
                                tabMatchB = tabMatchB.slice(0, tabMatchA.length) + strStart + tabMatchB.slice(tabMatchA.length) + strEnd;
                            }
                            return [tabMatchA, tabMatchB, splitA, splitB];
                        }()),
                        whiteout = function diffview_report_charcomp_whiteout(whitediff : string): string {
                            const spacetest: RegExp = (/<((em)|(pd))>\u0020+<\/((em)|(pd))>/),
                                crtest: RegExp = (/<((em)|(pd))>\r+<\/((em)|(pd))>/);
                            if (spacetest.test(whitediff) === true) {
                                return whitediff;
                            }
                            if (crtest.test(whitediff) === true) {