import { toTransformStream } from "../streams/to_transform_stream.ts";import type { JsonValue, ParseStreamOptions } from "./common.ts";import { parse } from "./_common.ts";
const blank = new Set(" \t\r\n");function isBrankChar(char: string) { return blank.has(char);}
export class ConcatenatedJsonParseStream implements TransformStream<string, JsonValue> { readonly writable: WritableStream<string>; readonly readable: ReadableStream<JsonValue>; constructor({ writableStrategy, readableStrategy }: ParseStreamOptions = {}) { const { writable, readable } = toTransformStream( this.#concatenatedJSONIterator, writableStrategy, readableStrategy, ); this.writable = writable; this.readable = readable; }
async *#concatenatedJSONIterator(src: AsyncIterable<string>) { let targetString = ""; let hasValue = false; let nestCount = 0; let readingString = false; let escapeNext = false; for await (const string of src) { let sliceStart = 0; for (let i = 0; i < string.length; i++) { const char = string[i];
if (readingString) { if (char === '"' && !escapeNext) { readingString = false;
if (nestCount === 0 && hasValue) { yield parse(targetString + string.slice(sliceStart, i + 1)); hasValue = false; targetString = ""; sliceStart = i + 1; } } escapeNext = !escapeNext && char === "\\"; continue; }
if ( hasValue && nestCount === 0 && (char === "{" || char === "[" || char === '"' || char === " ") ) { yield parse(targetString + string.slice(sliceStart, i)); hasValue = false; readingString = false; targetString = ""; sliceStart = i; i--; continue; }
switch (char) { case '"': readingString = true; escapeNext = false; break; case "{": case "[": nestCount++; break; case "}": case "]": nestCount--; break; }
if ( hasValue && nestCount === 0 && (char === "}" || char === "]") ) { yield parse(targetString + string.slice(sliceStart, i + 1)); hasValue = false; targetString = ""; sliceStart = i + 1; continue; }
if (!hasValue && !isBrankChar(char)) { hasValue = true; } } targetString += string.slice(sliceStart); } if (hasValue) { yield parse(targetString); } }}