Method advance

Extension/src/Utility/Text/scanner.ts:261–318

(count?: number)

    }

    private advance(count?: number): number {
        let codeOrChar: number;
        let newOffset: number;
        let offsetAdvancedBy = 0;

        switch (count) {
            case undefined:
            case 1:
                offsetAdvancedBy = this.#chSz;
                this.#offset += this.#chSz;
                this.#ch = this.#chNext; this.#chSz = this.#chNextSz;
                this.#chNext = this.#chNextNext; this.#chNextSz = this.#chNextNextSz;

                newOffset = this.#offset + this.#chSz + this.#chNextSz;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#chNextNext = (this.#chNextNextSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;
                return offsetAdvancedBy;

            case 2:
                offsetAdvancedBy = this.#chSz + this.#chNextSz;
                this.#offset += this.#chSz + this.#chNextSz;
                this.#ch = this.#chNextNext; this.#chSz = this.#chNextNextSz;

                newOffset = this.#offset + this.#chSz;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#chNext = (this.#chNextSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;

                newOffset += this.#chNextSz;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#chNextNext = (this.#chNextNextSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;
                return offsetAdvancedBy;

            default:
            case 3:
                offsetAdvancedBy = this.#chSz + this.#chNextSz + this.#chNextNextSz;
                count -= 3;
                while (count) {
                    // skip over characters while we work.
                    offsetAdvancedBy += sizeOf(this.#text.charCodeAt(this.#offset + offsetAdvancedBy));
                }
                this.#offset += offsetAdvancedBy;

            // eslint-disable-next-line no-fallthrough
            case 0:
                newOffset = this.#offset;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#ch = (this.#chSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;

                newOffset += this.#chSz;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#chNext = (this.#chNextSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;

                newOffset += this.#chNextSz;
                codeOrChar = this.#text.charCodeAt(newOffset);
                this.#chNextNext = (this.#chNextNextSz = sizeOf(codeOrChar)) === 1 ? codeOrChar : this.#text.codePointAt(newOffset)!;
                return offsetAdvancedBy;
        }
    }