go-option

README

go-option

Generates Go code using a package as a graceful option.

go-option Generates Go code using a package as a graceful options Given the name of a atomic.Value type T go-option will create a new self-contained Go source file implementing

// type TOption interface{
	apply(*Number)
}
// T
func (m *T) ApplyOptions(options ...TOption) *T

The file is created in the same package and directory as the package that defines T. It has helpful defaults designed for use with go generate.

For example, given this snippet,

package painkiller

type Pill struct{}

running this command

go-option -type "Pill"

in the same directory will create the file pill_options.go, in package painkiller, containing a definition of

var _default_Pill_value = func() (val Pill) { return }()

// A PillOptions sets options.
type PillOptions interface {
	apply(*Pill)
}
//
// EmptyPillOptions does not alter the configuration. It can be embedded
// in another structure to build custom options.
//
// This API is EXPERIMENTAL.
type EmptyPillOptions struct{}
//
func (EmptyPillOptions) apply(*Pill) {}
//
// PillOptionFunc wraps a function that modifies PillOptionFunc into an
// implementation of the PillOptions interface.
type PillOptionFunc func(*Number)
//
func (f PillOptionFunc) apply(do *Pill) {
	f(do)
}

func (o *Pill) ApplyOptions(options ...PillOption) *Pill {
	for _, opt := range options {
		if opt == nil {
			continue
		}
		opt.apply(o)
	}
	return o
}

Typically this process would be run using go generate, like this:

//go:generate go-option -type "Pill"

If multiple constants have the same value, the lexically first matching name will be used (in the example, Acetaminophen will print as "Paracetamol").

With no arguments, it processes the package in the current directory. Otherwise, the arguments must name a single directory holding a Go package or a set of Go source files that represent a single Go package.

The -type flag accepts a comma-separated list of types so a single run can generate methods for multiple types. The default output file is t_options.go, where t is the lower-cased name of the first type listed. It can be overridden with the -output flag.

Download/Install

The easiest way to install is to run go get -u github.com/searKing/golang/tools/cmd/go-option. You can also manually git clone the repository to $GOPATH/src/github.com/searKing/golang/tools/cmd/go-option.

Inspiring projects

• stringer

Documentation

Overview

Typically this process would be run using go generate, like this:

//go:generate go-option -type=Pill

With no arguments, it processes the package in the current directory. Otherwise, the arguments must name a single directory holding a Go package or a set of Go source files that represent a single Go package.

The -type flag accepts a comma-separated list of types so a single run can generate methods for multiple types. The default output file is t_string.go, where t is the lower-cased name of the first type listed. It can be overridden with the -output flag.