Skip to content

Usage & API

The public API lives at the module root (github.com/go-ruby-optparse/optparse). It is Ruby-shaped but Go-idiomatic: a Parser holds option Specs and produces Matches; the per-option callbacks OptionParser would invoke are the host's job. The surface follows Go conventions — an explicit error, value types, no global state.

Status: implemented

The library is built and importable as github.com/go-ruby-optparse/optparse, bound into rbgo as a native module; see Roadmap.

Install

go get github.com/go-ruby-optparse/optparse

Worked example

p := optparse.New()
p.On(optparse.Spec{Long: "verbose", Short: "v"})
p.On(optparse.Spec{Long: "level", Arg: optparse.Required, Type: optparse.Int})

m, rest, err := p.ParseBang([]string{"-v", "--lev=3", "file"})
// m matches -v and the abbreviated --level=3 (coerced to int 3)
// rest == []string{"file"}; the host runs each Spec's callback

Shape

// Parser holds the option specs and parses an argv against them.
type Parser struct{ /* ... */ }

// Spec describes one option (long/short names, argument, type).
type Spec struct{ /* ... */ }

// Match is one resolved option occurrence (which Spec, its value).
type Match struct{ /* ... */ }

// ParseBang implements parse! — permute and consume the argv,
// returning the matches, the residual argv, and any ParseError.
func (p *Parser) ParseBang(argv []string) (matches []Match, rest []string, err error)

MRI conformance

Correctness is defined by reference Ruby. A differential oracle runs a wide corpus through both the system ruby and this library and compares the results byte-for-byte — not approximated from memory. The oracle tests skip themselves where ruby is not on PATH (e.g. the qemu arch lanes), so the cross-arch builds still validate the library.

Relationship to Ruby

go-ruby-optparse/optparse is standalone and reusable, and is the backend bound into go-embedded-ruby by rbgo as a native module — the same way go-ruby-regexp and go-ruby-erb are bound. The dependency runs the other way: this library has no dependency on the Ruby runtime.