go-strcmd

The reflection-based package allows users to call methods with automatically parsed parameters, with strings.

The most common usecase is interactive cli that execute methods according to input from stdin.

func testInt(i1 int, i2 int) error {
	fmt.Print(i1 + i2)
    return nil
}

func Call () {
    strcmd := strcmd.NewStrCmd()
    strcmd.Call(testInt, []string {"123", "456"})
    strcmd.SplitAndCall(testInt, "123 456")
}

func NamedCall () {
    strcmd := strcmd.NewStrCmd()
    functions := map[string]any{
        "testInt": testInt,
        "testStr": func (arg string) error {
            _, err := fmt.Print(arg)
            return err
        },
    }
    strcmd.CallNamed("testInt 123 456", functions)
    strcmd.CallNamed("testStr '2 whitespaces here'", functions)
    strcmd.CallNamed("testStr \"2 whitespaces here\"", functions)
    strcmd.CallNamed("testStr '\\\''", functions)
}

Parsers

By default, most of the basic types are supported as parameters.

You can also add custom parser by strcmd.SetParser.

type testStruct struct {
    a int
}

func addParser () {
    strcmd := strcmd.NewStrCmd()
    strcmd.SetParser(reflect.TypeOf(testStruct{}).Name(),  func(from string) (any, error) {
        parsed, err := strconv.ParseInt(from, 10, 64)
        if err != nil {
            return testStruct { a: int(parsed) }, nil
        } else {
            return int(parsed), nil
        }
    })
}