web repl

.forgejo/workflows/webrepl.yaml

@@ -0,0 +1,40 @@
+name: webrepl
+on: [push]
+#on:
+#  push:
+#    branches:
+#      - main
+jobs:
+  test:
+    runs-on: docker
+
+    container:
+      image: rust:1.83-alpine
+
+    steps:
+      - name: Install dependencies
+        run: apk add --no-cache git nodejs util-linux
+
+      - name: Install wasm-pack
+        run: cargo install wasm-pack
+
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build talc-web
+        run: wasm-pack build --release --no-typescript --no-pack --target web
+        working-directory: talc-web
+
+      - name: Save artifacts
+        uses: forgejo/upload-artifact@v4
+        with:
+          name: webrepl
+          path: |
+            *.html
+            *.js
+            *.css
+            pkg/
+          if-no-files-found: error
+
+      - name: Done
+        run: echo done!

Cargo.lock

@@ -29,6 +29,12 @@ version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
 
+[[package]]
+name = "bumpalo"
+version = "3.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"
+
 [[package]]
 name = "byteorder"
 version = "1.5.0"
@@ -41,12 +47,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "cfg_aliases"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
-
 [[package]]
 name = "cfg_aliases"
 version = "0.2.1"
@@ -106,7 +106,7 @@ version = "3.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90eeab0aa92f3f9b4e87f258c72b139c207d251f9cbc1080a0086b86a8870dd3"
 dependencies = [
- "nix 0.29.0",
+ "nix",
  "windows-sys 0.59.0",
 ]
 
@@ -150,8 +150,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
 dependencies = [
  "cfg-if",
+ "js-sys",
  "libc",
  "wasi",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -169,6 +171,16 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "js-sys"
+version = "0.3.76"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6717b6b5b077764fb5966237269cb3c64edddde4b14ce42647430a78ced9e7b7"
+dependencies = [
+ "once_cell",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -208,18 +220,6 @@ dependencies = [
  "smallvec",
 ]
 
-[[package]]
-name = "nix"
-version = "0.28.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
-dependencies = [
- "bitflags",
- "cfg-if",
- "cfg_aliases 0.1.1",
- "libc",
-]
-
 [[package]]
 name = "nix"
 version = "0.29.0"
@@ -228,7 +228,7 @@ checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
 dependencies = [
  "bitflags",
  "cfg-if",
- "cfg_aliases 0.2.1",
+ "cfg_aliases",
  "libc",
 ]
 
@@ -306,6 +306,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.20.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.20"
@@ -417,9 +423,9 @@ dependencies = [
 
 [[package]]
 name = "rustyline"
-version = "14.0.0"
+version = "15.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7803e8936da37efd9b6d4478277f4b2b9bb5cdb37a113e8d63222e58da647e63"
+checksum = "2ee1e066dc922e513bda599c6ccb5f3bb2b0ea5870a579448f2622993f0a9a2f"
 dependencies = [
  "bitflags",
  "cfg-if",
@@ -429,12 +435,12 @@ dependencies = [
  "libc",
  "log",
  "memchr",
- "nix 0.28.0",
+ "nix",
  "radix_trie",
  "unicode-segmentation",
  "unicode-width",
  "utf8parse",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -445,9 +451,9 @@ checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 
 [[package]]
 name = "syn"
-version = "2.0.94"
+version = "2.0.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "987bc0be1cdea8b10216bd06e2ca407d40b9543468fafd3ddfb02f36e77f71f3"
+checksum = "46f71c0377baf4ef1cc3e3402ded576dccc315800fbc62dfc7fe04b009773b4a"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -495,6 +501,16 @@ dependencies = [
  "talc-macros",
 ]
 
+[[package]]
+name = "talc-web"
+version = "0.1.0"
+dependencies = [
+ "getrandom",
+ "talc-lang",
+ "talc-std",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.14"
@@ -509,9 +525,9 @@ checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
 
 [[package]]
 name = "unicode-width"
-version = "0.1.14"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
+checksum = "1fc81956842c57dac11422a97c3b8195a1ff727f06e85c84ed2e8aa277c9a0fd"
 
 [[package]]
 name = "utf8parse"
@@ -525,6 +541,60 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a474f6281d1d70c17ae7aa6a613c87fce69a127e2624002df63dcb39d6cf6396"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f89bb38646b4f81674e8f5c3fb81b562be1fd936d84320f3264486418519c79"
+dependencies = [
+ "bumpalo",
+ "log",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2cc6181fd9a7492eef6fef1f33961e3695e4579b9872a6f7c83aee556666d4fe"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30d7a95b763d3c45903ed6c81f156801839e5ee968bb07e534c44df0fcd330c2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "943aab3fdaaa029a6e0271b35ea10b72b943135afe9bffca82384098ad0e06a6"
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["talc-lang", "talc-bin", "talc-std", "talc-macros"]
+members = ["talc-lang", "talc-bin", "talc-std", "talc-macros", "talc-web"]
 resolver = "2"
 
 

docs/src/SUMMARY.md

@@ -4,6 +4,7 @@
 
 - [Installation](./install/installation.md)
 - [Tour of the REPL](./install/repl.md)
+- [The Web REPL](./install/webrepl.md)
 
 # The language
 

docs/src/install/webrepl.md

@@ -0,0 +1,18 @@
+# The Web REPL
+
+As an alterative to the command-line REPL, you can try out Talc in the browser
+at (https://talc.trimill.xyz/repl)[https://talc.trimill.xyz/repl]. Although
+the full Talc language and standard library (aside from file I/O and process
+control) are available, editing features are more limited than the command-line
+interface - especially of note is the lack of syntax highlighting and tab
+completion.
+
+## Usage
+
+Just like the command-line REPL, enter an expression and press Enter to
+evaluate it. Use the up and down arrows to access input history.
+
+For multiline editing, use Shift+Enter to insert a newline. Hold the Control
+key while pressing the up or down arrows to move the cursor between lines.
+
+To clear the screen, press Ctrl+L.

talc-bin/Cargo.toml

@@ -14,7 +14,7 @@ path = "src/main.rs"
 [dependencies]
 talc-lang = { path = "../talc-lang" }
 talc-std = { path = "../talc-std" }
-rustyline = "14.0"
+rustyline = "15.0"
 clap = { version = "4.5", features = ["std", "help", "usage", "derive", "error-context"], default-features = false }
 ctrlc = "3.4"
 lazy_static = "1.5"

talc-bin/src/helper.rs

@@ -2,7 +2,7 @@ use std::{borrow::Cow, cell::RefCell, rc::Rc};
 
 use rustyline::{
 	completion::Completer,
-	highlight::Highlighter,
+	highlight::{CmdKind, Highlighter},
 	hint::Hinter,
 	validate::{ValidationContext, ValidationResult, Validator},
 	Helper, Result,
@@ -105,8 +105,11 @@ impl Highlighter for TalcHelper {
 		Cow::Owned(format!("\x1b[37m{hint}\x1b[0m"))
 	}
 
-	fn highlight_char(&self, line: &str, _: usize, forced: bool) -> bool {
-		forced || !line.is_empty()
+	fn highlight_char(&self, line: &str, _: usize, forced: CmdKind) -> bool {
+		match forced {
+			CmdKind::ForcedRefresh => true,
+			_ => !line.is_empty(),
+		}
 	}
 }
 

talc-lang/Cargo.toml

@@ -8,6 +8,6 @@ rust-version = "1.81.0"
 workspace = true
 
 [dependencies]
-num = { version = "0.4", features = [] }
+num = "0.4"
 lazy_static = "1.5"
 unicode-ident = "1.0"

talc-lang/src/compiler.rs

@@ -1,5 +1,5 @@
-use core::fmt;
 use std::collections::HashMap;
+use std::fmt;
 use std::rc::Rc;
 
 use crate::chunk::{Arg24, Catch, Chunk, Instruction as I};

talc-lang/src/exception.rs

@@ -3,7 +3,7 @@ use crate::{
 	symbol::{Symbol, SYM_MSG, SYM_TRACE, SYM_TYPE},
 	value::Value,
 };
-use std::{fmt::Display, rc::Rc};
+use std::{error::Error, fmt::Display, rc::Rc};
 
 pub type Result<T> = std::result::Result<T, Exception>;
 
@@ -114,6 +114,8 @@ impl Display for Exception {
 	}
 }
 
+impl Error for Exception {}
+
 #[macro_export]
 macro_rules! exception {
 	($exc_ty:expr, $($t:tt)*) => {

talc-lang/src/number/int.rs

@@ -1,4 +1,3 @@
-use core::{f64, panic};
 use std::{borrow::Cow, cmp::Ordering, fmt, hash::Hash, mem::ManuallyDrop, ops, rc::Rc};
 
 use num::{

talc-lang/src/optimize.rs

@@ -1,5 +1,3 @@
-use core::panic;
-
 use crate::{
 	parser::ast::{CatchBlock, Expr, ExprKind, LValue, LValueKind, ListItem, TableItem},
 	value::Value,

talc-lang/src/parser/ast.rs

@@ -1,4 +1,4 @@
-use core::fmt;
+use std::fmt;
 
 use crate::{
 	ops::{BinaryOp, UnaryOp},

talc-lang/src/parser/util.rs

@@ -1,5 +1,4 @@
-use core::fmt;
-use std::num::ParseFloatError;
+use std::{fmt, num::ParseFloatError};
 
 use num::{bigint::ParseBigIntError, Num};
 

talc-lang/src/serial/mod.rs

@@ -1,4 +1,4 @@
-use core::fmt;
+use std::fmt;
 use std::io::{self, Write};
 
 use num::{bigint::Sign, BigInt};

talc-std/Cargo.toml

@@ -16,6 +16,7 @@ regex = { version = "1.11", optional = true }
 rand = { version = "0.8", optional = true }
 
 [features]
-default = ["rand", "regex"]
+default = ["rand", "regex", "file"]
 rand = ["dep:rand", "dep:num-bigint"]
 regex = ["dep:regex"]
+file = []

talc-std/src/file.rs

@@ -678,6 +678,7 @@ fn spawn_inner(fname: &str, proc: &mut Command, opts: Value) -> Result<Value> {
 		Ok(c) => c,
 		Err(e) => throw!(*SYM_IO_ERROR, "{e}"),
 	};
+	#[expect(clippy::mutable_key_type)]
 	let mut table = HashMap::new();
 	if let Some(stdin) = child.stdin.take() {
 		let bf = match BufFile::from_raw_fd(stdin.into_raw_fd(), true) {

talc-std/src/io.rs

@@ -1,6 +1,5 @@
 use std::{
 	io::{BufRead, Write},
-	os::unix::ffi::OsStrExt,
 	sync::Mutex,
 	time::{SystemTime, UNIX_EPOCH},
 };
@@ -127,7 +126,7 @@ pub fn env(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
 	}
 	let val = std::env::var_os(key.to_os_str());
 	match val {
-		Some(val) => Ok(LString::from(val.as_bytes()).into()),
+		Some(val) => Ok(LString::from(val.as_encoded_bytes()).into()),
 		None => Ok(Value::Nil),
 	}
 }

talc-std/src/iter.rs

@@ -619,6 +619,7 @@ pub fn list(vm: &mut Vm, args: Vec<Value>) -> Result<Value> {
 pub fn table(vm: &mut Vm, args: Vec<Value>) -> Result<Value> {
 	let [_, iter] = unpack_args!(args);
 	let iter = iter.to_iter_function()?;
+	#[expect(clippy::mutable_key_type)]
 	let mut result = HashMap::new();
 	while let Some(value) = vmcalliter!(vm; iter.clone())? {
 		let Value::List(l) = value else {
@@ -851,6 +852,7 @@ pub fn count(vm: &mut Vm, args: Vec<Value>) -> Result<Value> {
 	let [_, iter] = unpack_args!(args);
 	let iter = iter.to_iter_function()?;
 
+	#[expect(clippy::mutable_key_type)]
 	let mut map = HashMap::new();
 
 	while let Some(v) = vmcalliter!(vm; iter.clone())? {

talc-std/src/lib.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::mutable_key_type)]
-
 use talc_lang::{
 	symbol::{symbol, Symbol},
 	vm::Vm,
@@ -7,7 +5,6 @@ use talc_lang::{
 
 pub mod collection;
 pub mod exception;
-pub mod file;
 pub mod format;
 pub mod ints;
 pub mod io;
@@ -16,6 +13,8 @@ pub mod math;
 pub mod string;
 pub mod value;
 
+#[cfg(feature = "file")]
+pub mod file;
 #[cfg(feature = "rand")]
 pub mod random;
 #[cfg(feature = "regex")]
@@ -24,7 +23,6 @@ pub mod regex;
 pub fn load_all(vm: &mut Vm) {
 	collection::load(vm);
 	exception::load(vm);
-	file::load(vm);
 	format::load(vm);
 	io::load(vm);
 	iter::load(vm);
@@ -33,6 +31,8 @@ pub fn load_all(vm: &mut Vm) {
 	string::load(vm);
 	value::load(vm);
 
+	#[cfg(feature = "file")]
+	file::load(vm);
 	#[cfg(feature = "rand")]
 	random::load(vm);
 	#[cfg(feature = "regex")]

talc-std/src/value.rs

@@ -130,11 +130,14 @@ pub fn copy_inner(value: Value) -> Result<Value> {
 			Ok(v?.into())
 		}
 		Value::Table(t) => {
+			#[expect(clippy::mutable_key_type)]
 			let t = Rc::unwrap_or_clone(t).take();
+
 			let v: Result<HashMap<HashValue, Value>> = t
 				.into_iter()
 				.map(|(k, v)| copy_inner(v).map(|v| (k, v)))
 				.collect();
+
 			Ok(v?.into())
 		}
 		Value::Native(ref n) => match n.copy_value()? {

talc-web/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "talc-web"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[lints]
+workspace = true
+
+[dependencies]
+talc-lang = { path = "../talc-lang" }
+talc-std = { path = "../talc-std", default-features = false, features = ["rand", "regex"] }
+getrandom = { version = "0.2", features = ["js"] }
+wasm-bindgen = "0.2"

talc-web/README.md

@@ -0,0 +1,16 @@
+# Talc Web
+
+The `talc-web` crate provides a WASM interface to execute Talc expressions
+in a REPL. Together with the associated HTML, CSS, and JavaScript files, this
+creates an alternative to the command-line REPL.
+
+## Building
+
+In the `talc-web` directory, run:
+
+```bash
+wasm-pack build --release --no-typescript --no-pack --target web
+```
+
+See (the main README.md)[../README.md] for more information about building
+Talc.

talc-web/index.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="utf-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+
+	<title>Talc Web REPL</title>
+
+	<script type="module" src="main.js"></script>
+
+	<link rel="stylesheet" href="style.css">
+</head>
+<body>
+	<div id="terminal">
+		<div id="history">
+			<div>Talc Web REPL</div>
+			<div>For help, see
+				<a href="https://talc.trimill.xyz/" target="_blank">the docs</a>
+				or
+				<a href="https://g.trimill.xyz/trimill/talc" target="_blank">the repository</a>
+			</div>
+		</div>
+		<div class="input_line">
+			<div id="prompt" class="prompt">&gt;&gt;&nbsp;</div>
+			<div id="input" style="display: inline-block" contenteditable="true"></div>
+		</div>
+	</div>
+</body>
+</html>

talc-web/main.js

@@ -0,0 +1,161 @@
+"use strict";
+
+import init, * as talc from "./pkg/talc_web.js";
+await init();
+
+/*
+ *  DOM
+ */
+
+const $ = (q) => document.querySelector(q);
+
+function newEl(tag, attrs, children) {
+	const el = document.createElement(tag);
+	for (const attr in attrs) {
+		el.setAttribute(attr, attrs[attr]);
+	}
+	for (const child of children) {
+		if (typeof(child) === "string") {
+			el.appendChild(document.createTextNode(child));
+		} else {
+			el.appendChild(child);
+		}
+	}
+	return el;
+}
+
+/*
+ *  History
+ */
+
+let historyEntries = [""];
+let historyIndex = 0;
+let currentLine = "";
+
+function prevHistory() {
+	const inputEl = $("#input");
+	if (historyIndex === 0) {
+		currentLine = inputEl.innerText;
+	}
+	historyIndex = Math.min(historyIndex+1, historyEntries.length);
+	const text = historyEntries[historyEntries.length - historyIndex];
+	inputEl.innerText = text;
+
+	document.getSelection().setPosition(inputEl, inputEl.childNodes.length);
+}
+
+function nextHistory() {
+	const inputEl = $("#input");
+	historyIndex = Math.max(historyIndex-1, 0);
+	let text;
+	if (historyIndex === 0) {
+		text = currentLine;
+	} else {
+		text = historyEntries[historyEntries.length - historyIndex];
+	}
+	inputEl.innerText = text;
+
+	document.getSelection().setPosition(inputEl, inputEl.childNodes.length);
+}
+
+/*
+ *  REPL
+ */
+
+function nextLine() {
+	const newPrompt = newEl("div", {"class": "prompt"}, []);
+	newPrompt.innerHTML = $("#prompt").innerHTML;
+
+	const newInput = newEl("div", {}, []);
+	newInput.innerHTML = $("#input").innerHTML;
+
+	$("#history").appendChild(newEl(
+		"div",
+		{"class": "input_line"},
+		[newPrompt, newInput]
+	));
+
+	$("#input").innerHTML = "";
+
+	currentLine = "";
+	historyIndex = 0;
+
+}
+
+function execLine() {
+	const inputLine = $("#input").innerText;
+	nextLine();
+	historyEntries.push(inputLine);
+
+	try {
+		const fixedInput = inputLine.replaceAll("\u00a0", " ");
+		const out = talc.eval_line(fixedInput);
+		if (out !== undefined) {
+			$("#history").appendChild(newEl("div", {}, [out]));
+		}
+	} catch (e) {
+		$("#history").appendChild(newEl("div", {}, [
+			newEl("span", {"class": "error"}, ["Error: "]),
+			newEl("pre", {"class": "err_msg"}, [e.toString()])
+		]));
+	}
+}
+
+/*
+ *  Input
+ */
+
+function handleCtrlKey(event) {
+	switch (event.code) {
+		case "KeyL":
+			event.preventDefault();
+			$("#history").innerHTML = "";
+			break;
+		case "KeyC":
+			event.preventDefault();
+			nextLine();
+			break;
+	}
+}
+
+function keyPressed(event) {
+	if (event.key === "Enter" && !event.shiftKey) {
+		event.preventDefault();
+		execLine()
+	} else if (event.ctrlKey) {
+		handleCtrlKey(event);
+	} else if (event.key === "ArrowUp") {
+		event.preventDefault();
+		prevHistory();
+	} else if (event.key === "ArrowDown") {
+		event.preventDefault();
+		nextHistory();
+	}
+
+	window.scrollTo(0, document.body.scrollHeight);
+}
+
+/*
+ *  Listeners
+ */
+
+$("#input").addEventListener("keydown", keyPressed);
+$("#input").focus();
+
+$("#terminal").addEventListener("click", (event) => {
+	if (event.target.id === "terminal" || event.target.id === "input") {
+		$("#input").focus();
+	}
+})
+
+/*
+ *  Query parameter
+ */
+
+const urlParams = new URLSearchParams(window.location.search);
+const initialLine = urlParams.get("eval");
+
+if (initialLine !== null) {
+	$("#input").innerText = initialLine;
+	execLine();
+}

talc-web/src/lib.rs

@@ -0,0 +1,51 @@
+use std::{cell::RefCell, rc::Rc};
+
+use talc_lang::{
+	compiler, parser,
+	symbol::{symbol, Symbol},
+	value::Value,
+	vm::Vm,
+};
+use wasm_bindgen::prelude::wasm_bindgen;
+
+type BoxError = Box<dyn std::error::Error>;
+
+struct Talc {
+	vm: Vm,
+	globals: Vec<Symbol>,
+}
+
+impl Talc {
+	pub fn eval_line(&mut self, line: &str) -> Result<Option<String>, BoxError> {
+		let expr = parser::parse(line)?;
+		let func = compiler::compile_repl(&expr, &mut self.globals)?;
+		let func = Rc::new(func);
+		let res = self.vm.run_function(func.clone(), vec![func.into()])?;
+		let res_str = (res != Value::Nil).then(|| format!("{res:#}"));
+		self.vm.set_global(symbol!("_"), res);
+		Ok(res_str)
+	}
+}
+
+thread_local! {
+	static TALC: RefCell<Talc> = {
+		let mut vm = Vm::new(128, Vec::new());
+		talc_std::load_all(&mut vm);
+
+		let globals = vec![symbol!("_")];
+		vm.set_global(symbol!("_"), Value::Nil);
+
+		RefCell::new(Talc { vm, globals })
+	}
+}
+
+#[wasm_bindgen(start)]
+pub fn start() {
+	TALC.with(|_| ());
+}
+
+#[wasm_bindgen]
+pub fn eval_line(line: &str) -> Result<Option<String>, String> {
+	TALC.with_borrow_mut(|t| t.eval_line(line))
+		.map_err(|e| e.to_string())
+}

talc-web/style.css

@@ -0,0 +1,57 @@
+body {
+	font-family: monospace;
+	font-size: 14pt;
+
+	background-color: #14171d;
+	color: #c7c6c3;
+
+	margin: 20px;
+}
+
+.input_line {
+	display: flex;
+}
+
+#prompt {
+	margin-bottom: 100px;
+}
+
+#input {
+	width: 100%;
+}
+
+#input:focus {
+	outline: none;
+}
+
+div, pre {
+	margin: 0;
+	padding: 0;
+}
+
+#terminal {
+	min-height: calc(100vh - 60px - 8px);
+	padding: 10px;
+	border: 4px solid #4d4754;
+	border-radius: 6px;
+}
+
+a {
+	color: #82bfb3;
+}
+
+a:visited {
+	color: #82bfb3;
+}
+
+pre.err_msg {
+	display: inline;
+}
+
+.error {
+	color: #cc5c5c;
+}
+
+.prompt {
+	color: #789ebf;
+}