json-as/assembly/deserialize/simple/array/map.ts

The only JSON library you'll need for AssemblyScript. SIMD enabled

import { BRACE_LEFT, BRACE_RIGHT, BRACKET_LEFT, BRACKET_RIGHT } from "../../../custom/chars";
import { JSON } from "../../..";
import { isSpace } from "util/string";

export function deserializeMapArray<T extends Map<any, any>[]>(srcStart: usize, srcEnd: usize, dst: usize): T {
  const out = changetype<nonnull<T>>(dst || changetype<usize>(instantiate<T>()));
  let lastIndex: usize = 0;
  let depth: u32 = 0;

  while (srcStart < srcEnd && isSpace(load<u16>(srcStart))) srcStart += 2;
  while (srcEnd > srcStart && isSpace(load<u16>(srcEnd - 2))) srcEnd -= 2;

  if (srcStart - srcEnd == 0) throw new Error("Input string had zero length or was all whitespace");

  if (load<u16>(srcStart) != BRACKET_LEFT) throw new Error("Expected '[' at start of object at position " + (srcEnd - srcStart).toString());
  if (load<u16>(srcEnd - 2) != BRACKET_RIGHT) throw new Error("Expected ']' at end of object at position " + (srcEnd - srcStart).toString());

  while (srcStart < srcEnd) {
    const code = load<u16>(srcStart);
    if (code == BRACE_LEFT && depth++ == 0) {
      lastIndex = srcStart;
    } else if (code == BRACE_RIGHT && --depth == 0) {
      out.push(JSON.__deserialize<valueof<T>>(lastIndex, (srcStart += 2)));
    }
    srcStart += 2;
  }
  return out;
}