narg - Nested arguments as configuration

Installation

go get github.com/nochso/narg

Documentation

See godoc for API docs and examples.

Decoding configuration

Given a configuration struct consisting of scalar types, structs and slices:

type testConf struct {
	Name   string
	Port   int
	Debug  bool
	Float  float32
	Hosts  []string
	Ports  []int
	PortsU []uint8
	Admin  testUser
	Users  []testUser
}

type testUser struct {
	ID   int    `narg:"0"`
	Name string `narg:"1"`
}

Note that users can be defined using positional arguments instead of named ones. The order of the arguments is defined using the struct tag narg with the zero-based index (see testUser struct above).

The following narg input can be decoded into a pointer to testConf:

in := `name foo
port 80
debug 1
float 3.14
hosts a bee "cee e"
ports 1024 1025
portsu 0xff 255
admin {
	id 1
	name "Phil \"Tandy\" Miller"
}
users {
	id 2
	name "Carol Pilbasian"
}
users 4 Todd`
cfg := &testConf{}
err := Decode(strings.NewReader(in), cfg)

Field names are case-insensitive.

cfg has now been populated with the given narg input:

cfg = &testConf{
    Name:   "foo",
    Port:   80,
    Debug:  true,
    Float:  3.14,
    Hosts:  []string{"a", "bee", "cee e"},
    Ports:  []int{1024, 1025},
    PortsU: []uint8{0xff, 0xff},
    Admin: testUser{
        ID:   1,
        Name: `Phil "Tandy" Miller`,
    },
    Users: []testUser{
        {2, "Carol Pilbasian"},
        {4, "Todd"},
    },
}

Currently only supplied values are overwritten. You can set up your struct with sane defaults and when decoding a sparse config the defaults will be kept.

License

This package is released under the MIT license.