reply.js

"use strict";
function teen(s) { return (new TextEncoder()).encode(s); }
function tede(s) { return (new TextDecoder()).decode(s); }
function tedea(a) { return (new TextDecoder()).decode(Uint8Array.from(a)); }

async function mkRepl() {
  const repl = {};
  repl.postRun = () => {};
  repl.runBlob = function(f, args, blob) {
      repl.args = args.map(teen);
      repl.buf = [];
      repl.out = [];
      repl.inp = blob;
      repl.cursor = 0;
      repl.instance.exports[f]();
      repl.eval_in = [], repl.eval_out = [];
      repl.postRun();
      return {
        buf : repl.buf.map(tedea),
        out : tedea(repl.out),
      }
    };
  repl.run = function(f, args, s) { return repl.runBlob(f, args, teen(s)); }
  const importObj = {env:
    { putchar: c  => repl.out.push(c)
    , eof    : () => repl.cursor == repl.inp.length
    , getchar: () => repl.inp[repl.cursor++]
    , nextout: () => { repl.buf.push(repl.out); repl.out = []; }
    , argc   : () => repl.args.length
    , argvlen: i => repl.args[i].length
    , argvat : (i, j) => repl.args[i][j]

    , eval_put : c  => repl.eval_in.push(c)
    , eval_run : () => {
        const a = eval(tedea(repl.eval_in));
        repl.eval_out = a instanceof Uint8Array ? a : teen(a);
        repl.eval_in = [];
      }
    , eval_size: () => repl.eval_out.length
    , eval_at:   i  => repl.eval_out[i]
    }};
  const p = await WebAssembly.instantiateStreaming(fetch('../compiler/doh.wasm'), importObj);
  repl.instance = p.instance;
  repl.module = p.module;
  repl.fetch_module = async function(url) {
    const response = await fetch(url);
    if (!response.ok) throw new Error(`Response status: ${response.status}`);
    const bl = new Uint8Array(await (await response.blob()).arrayBuffer());
    repl.runBlob("chat_module", [], bl);
  }
  repl.reset = async function() {
    repl.instance = await WebAssembly.instantiate(repl.module, importObj);
    repl.run("chat_new", ["Main"], "");
  }
  repl.run("chat_new", ["Main"], "");
  return repl;
}