[go-nuts] named, ordered parameters in Go

I want to have something like named, ordered parameters in Go, and came to
the following solution:

package main

import "fmt"

type param struct {
name, value string
}

func main() {
show([]param{{"x", "1"}, {"y", "b"}, {"z", "abc"}})
}

func show(params []param) {
for _, item := range params {
fmt.Println(item.name + ": " + item.value)
}
}

http://play.golang.org/p/MddW-Rpuyg

Simulating named parameters with show([]param{{"x", "1"}, {"y", "b"}, {"z",
"abc"}}) looks ok, even though I'd prefer show(x="1", y="b", z="abc") like
in Python. I tried a map, which has a litte bit more concise syntax, but
lacks a defined order. Any better idea?

In real life the values are not always strings and have to be converted
therefore. I tried interface{}, but that didn't help because the format
string depends on the actual type. Then I tried fmt.Stringer interface, but
that ist not implement by string, int and other fundamental types. Is there
a way to handle this?

--

Is this just a "want" or was there some problem you had that named,
ordered parameters would solve?

Because once one has noticed ... arguments and explicit struct arguments
and map arguments, there doesn't seem to be much demand for such a feature.

Chris

The approach sacrifies both execution speed and compilation time type
safety checks. What is the reason for it?

-j

--

This solve the problem without adding language features (they are
blocked until 2.0 anyway) and you still have fast compilation, fast
execution, type-safety and a consistent API.

package main

import "fmt"

type MyArgs struct {
Arg1 int
Arg2 int
Arg3 int
}
func fn1(data MyArgs) {
fmt.Printf("data: %v\n", data)
}

func main() {
fn1(MyArgs{Arg1: 10})
}

sounds like your function does too much . if you really need this feature and you can't split your function up into smaller ones then create different functions with appropriate names that call your function with appropriate defaults

--