David Johnson dmjio

🔋 The `miso` tool, from scratch: a library, a web app, a command line app, and tests

A walk through the miso command line tool: one binary with MicroHs (0.16.10) and MicroCabal inside, and miso 1.14 already installed. We make a project called todo with:

a library (src/Todo.hs): the todo list itself, with no UI;
a web app (app/Main.hs, target: browser): miso, WebAssembly;
a command line app (cli/Cli.hs, target: native);
a test suite (test/Spec.hs).

encodeUtf8 returned Text's internal bytes unchanged, so text containing a NUL came out as invalid UTF-8, and decodeUtf8 couldn't read it back.

The problem

Text stores modified UTF-8: NUL is the two bytes C0 80, so a Text never has a 0 byte, which the runtime's C strings need. That's fine internally, but encodeUtf8 returned those bytes as they are, and standard UTF-8 forbids C0 80 (an overlong encoding). So:

>>> B.unpack (encodeUtf8 (pack "a\0b"))
[97,192,128,98]                                   -- not UTF-8
>>> decodeUtf8 (encodeUtf8 (pack "a\0b"))

	initBackground();

	globalThis['renderPage'] = function () {
	console.log('in main');
	console.log('getting global emitter in main should fail', 'getJSModule' in lynx);
	const context = lynx.getJSContext();
	console.log('js context', context);

	// dmj: this works
	context.addEventListener("message", (event) => {

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>WebSocket API Example</title>
	<style>
	* {
	margin: 0;
	padding: 0;

	{-# LANGUAGE OverloadedStrings #-}
	{-# LANGUAGE RecordWildCards #-}
	{-# LANGUAGE TypeApplications #-}
	module TailwindUI.Components where

	import Miso
	import Miso.String (MisoString, ms)
	import qualified Data.Map as Map

	-- ========================

	{-# LANGUAGE OverloadedStrings #-}
	module DaisyUI where

	import Miso
	import Miso.String (MisoString, ms)

	-- Action type for all component interactions
	data Action
	= ButtonClicked MisoString
	\| AccordionToggled Int

	import Data.List (foldl', tails)
	import Data.Map.Internal.Debug
	import qualified Data.Map.Strict as M
	import Data.Maybe
	import Data.Monoid
	import qualified Data.Set as S

	data TrieValue v
	= TrieValue
	{ next :: Trie v








	Build failed.
	error: builder for '/nix/store/4nb133jpb8np159fs5c63gjn35h5pl0k-wasm32-unknown-wasi-ghc-native-bignum-9.6.5.drv' failed with exit code 1;
	last 10 log lines:

David Johnson dmjio

🔋 The miso tool, from scratch: a library, a web app, a command line app, and tests

The problem

🔋 The `miso` tool, from scratch: a library, a web app, a command line app, and tests