sourav-das/stem-separator

1const bufLength = 1024 * 16;2 3// Provide a fallback for older environments.4const td =5  typeof TextDecoder !== 'undefined'6    ? /* #__PURE__ */ new TextDecoder()7    : typeof Buffer !== 'undefined'8      ? {9          decode(buf: Uint8Array): string {10            const out = Buffer.from(buf.buffer, buf.byteOffset, buf.byteLength);11            return out.toString();12          },13        }14      : {15          decode(buf: Uint8Array): string {16            let out = '';17            for (let i = 0; i < buf.length; i++) {18              out += String.fromCharCode(buf[i]);19            }20            return out;21          },22        };23 24export class StringWriter {25  pos = 0;26  private out = '';27  private buffer = new Uint8Array(bufLength);28 29  write(v: number): void {30    const { buffer } = this;31    buffer[this.pos++] = v;32    if (this.pos === bufLength) {33      this.out += td.decode(buffer);34      this.pos = 0;35    }36  }37 38  flush(): string {39    const { buffer, out, pos } = this;40    return pos > 0 ? out + td.decode(buffer.subarray(0, pos)) : out;41  }42}43 44export class StringReader {45  pos = 0;46  declare private buffer: string;47 48  constructor(buffer: string) {49    this.buffer = buffer;50  }51 52  next(): number {53    return this.buffer.charCodeAt(this.pos++);54  }55 56  peek(): number {57    return this.buffer.charCodeAt(this.pos);58  }59 60  indexOf(char: string): number {61    const { buffer, pos } = this;62    const idx = buffer.indexOf(char, pos);63    return idx === -1 ? buffer.length : idx;64  }65}66