README
wasm-devkit
WIT and WAC syntax tools for files and stdin
Author
Version
0.1.1
License
Apache-2.0
Repository
Last updated
5 days ago
Downloads
21
#wasm-devkit CLI
Syntax tools for WIT and WAC. The CLI parses and diagnoses source, inspects tokens and
immutable AST/CST arenas, prints canonical AST source and formats while retaining comments.
It performs no package resolution or composition evaluation.
#Install
Run version 0.1.1 without installing:
moonx moonrockz/wasm-devkit@0.1.1 --help
moonx moonrockz/wasm-devkit@0.1.1 parse example.witInstall the native release with mise's GitHub backend:
mise use github:moonrockz/wasm-devkit@0.1.1
mise exec -- wasm-devkit --versionNative archives cover Linux x64, macOS arm64 and Windows x64, with SHA-256 sidecars.
The moonx executable uses Wasm and the same pinned library versions.
From this repository, mise run cli -- --help or
moon run cmd/wasm-devkit --target wasm -- --help runs the local sources.
mise run build:cli builds, smoke-tests and packages a native host archive under dist/.
#Scenarios
#Check and format a WIT interface
Save this as hello.wit:
// Public API
package example:greeter;
interface greeter{hello: func(name: string)->string;}moonx moonrockz/wasm-devkit@0.1.1 parse hello.wit
moonx moonrockz/wasm-devkit@0.1.1 format hello.witParsing writes hello.wit: valid wit. Formatting writes this source to stdout:
// Public API
package example:greeter;
interface greeter {
hello: func(name: string) -> string;
}Use format to retain comments. print regenerates canonical source from the AST.
The WIT library recipes show how to perform
these operations in MoonBit code.
#Inspect a WAC composition
Save this as app.wac:
package example:app;
import host: interface { log: func(message: string); };
let app = new example:service { host, ... };
export app.run as "run";moonx moonrockz/wasm-devkit@0.1.1 parse app.wac
moonx moonrockz/wasm-devkit@0.1.1 ast app.wac
moonx moonrockz/wasm-devkit@0.1.1 cst app.wac
moonx moonrockz/wasm-devkit@0.1.1 tokens app.wacParsing writes app.wac: valid wac. The inspection commands show typed node fields,
concrete token ranges and raw token spelling. Parsing does not fetch example:service
or check whether the composition is semantically valid.
The WAC library recipes show how to index
imports and bindings or preserve grouping during a rewrite.
#Enforce formatting in CI and apply it locally
moonx moonrockz/wasm-devkit@0.1.1 format --check hello.wit
moonx moonrockz/wasm-devkit@0.1.1 format --write hello.wit
moonx moonrockz/wasm-devkit@0.1.1 format --check hello.witThe compact input above first returns status 1 because layout differs. --write updates
the named file after successful formatting; the last check then returns 0.
Malformed source returns diagnostics and leaves the file unchanged. Use --indent 4
when your project uses four spaces.
#Process stdin or enable proposal syntax
In a POSIX shell:
cat hello.wit | moonx moonrockz/wasm-devkit@0.1.1 format --language witIn PowerShell:
Get-Content -Raw hello.wit | moonx moonrockz/wasm-devkit@0.1.1 format --language witStdin needs --language because it has no extension. --write needs a named file.
For documented extensions such as WIT fixed-length lists or WAC named results, pass the
same profile when parsing and formatting. Save this as proposals.wit:
interface arrays { type words = list<u8, 16>; }moonx moonrockz/wasm-devkit@0.1.1 parse --all-features proposals.wit
moonx moonrockz/wasm-devkit@0.1.1 format --all-features proposals.witFor WAC, save this as callbacks.wac and use --all-features with the .wac file:
package example:types;
type callback = func() -> (value: u8);See the WIT parser profile and
WAC parser profile for the exact syntax covered.
#Command reference
wasm-devkit parse example.wit
wasm-devkit ast example.wac
wasm-devkit cst example.wit
wasm-devkit tokens example.wac
wasm-devkit print example.wac
wasm-devkit format example.wit
wasm-devkit format --check example.wit
wasm-devkit format --write example.wac
cat example.wit | wasm-devkit parse --language witOne input is accepted per invocation. The CLI infers the language from .wit or .wac;
--language wit|wac overrides inference and is required for stdin or other extensions.
Input defaults to stdin; - selects stdin explicitly. Use -- before a filename starting
with a hyphen. --indent 0..8 controls indentation, with a default of two spaces.
--all-features enables the grammar extensions documented by each parser.
Diagnostics go to stderr as file:line:column: severity CODE: message. Lines and columns
are 1-based and count UTF-16 code units. Source files must be valid UTF-8; decoding preserves
a leading BOM for the language scanner to handle. ast, cst and tokens emit indexed,
flat inspection rows to stdout, including recovered structures. Typed data and raw token
text use escaped MoonBit debug notation. This inspection format may evolve.
print requires valid original syntax and emits canonical source from the AST, discarding
trivia. format retains non-whitespace token spelling and comments. Its default writes to
stdout. --check emits no source and fails when layout differs. --write requires a named
file, validates before writing and checks whether the source changed after the initial read.
It never writes malformed input. Check and write modes are mutually exclusive.
Exit status is 0 on success, 1 for syntax errors or formatting differences, and 2
for usage, decoding, I/O or internal output failures. No partial print/format source is emitted
on errors. The unchanged CST remains available for lossless recovery through the libraries.
#Development checks
The command core runs on wasm, wasm-gc, js and native. The I/O executable supports Wasm
and native through moonbitlang/async. mise run test:cli -- wasm and
mise run test:cli -- native exercise real files, redirected stdin, stdout/stderr, status
codes and formatter writes. mise run test:cli -- --binary PATH checks a packaged executable;
--moonx VERSION checks the published registry package.
Apache-2.0
Updated 5 days ago
21 downloads