minohm-go

A Go implementation of the minohm interface, for using Ohm grammars from Go.

A grammar blob is an Ohm grammar that has been compiled to .wasm via the @ohm-js/wasm NPM package. To use a grammar blob to match some input, you need a miniohm implementation for your host language of choice (JavaScript, Go, Python, etc.) This package provides a miniohm implementation for the Go Programming Language.

Overview

• The miniohm module is in matcher.go and cst.go.
• An example can be found in cmd/example/main.go.

Compiling grammars to Wasm

Use the ohm2wasm command from the @ohm-js/wasm NPM package to compile a .ohm file to a Wasm grammar blob. For example:

npx ohm2wasm myGrammar.ohm

See Makefile for an example.

Matching input

Create a new WasmMatcher and use the Match function:

matcher := NewWasmMatcher(ctx)
err := matcher.LoadModule("path/to/grammar.wasm")
matcher.SetInput("text to match")
success, err := matcher.Match()
cstRoot, err := matcher.GetCstRoot()

Walking the CST

A full implementation of semantics, operations, etc. is not part of the miniohm interface. Instead, you can walk the CST (concrete syntax tree) directly using the CstNode interface. See cmd/example/main.go for an example.

Developing

Useful commands:

make # Build
make test # Run tests