name: mbt-wasip1-tools description: Build small MoonBit WASIp1 CLI tools using the peter-jerry-ye/wasi library, focused on simple read/write tasks (echo, cat, wc, simple file ops). Use when creating or updating CLI examples, scripts, or skills for this repo.

MoonBit WASIp1 Tools

Use the examples

• Copy a project from assets/ and modify it.
• Each example is a complete MoonBit project with a README.
• Build with moon build -C <example-dir> and run with wasmtime run --dir host::guest <wasm>.

Path resolution (WASIp1)

• There is no cwd. All paths resolve against preopened directories.
• Resolution uses longest-prefix matching on preopen names.
• Relative paths must match a preopen prefix (for example, foo/bar requires a preopen named foo).
• Absolute paths only work when a preopen name starts with / (for example, --dir /host::/).
• If no prefix matches, fail immediately. Do not fall back to trial-and-error.

Unified stdio

• @wasi/stdio.stdin implements @sync_io.Reader and @io.Reader.
• @wasi/stdio.stdout and @wasi/stdio.stderr implement @sync_io.Writer and @io.Writer.

References

• references/api.md summarizes the core I/O and fs APIs.