A type switch will clean that up a fair bit.
var val interface{}
var ok bool
switch m := m.(type) {
case m.(map[string]int):
val, ok = mt.Mi[mk]
case m.(map[string]i
nterface{}):
val, ok = mt.Mi[mk]
case m.(map[string][]int):
val, ok = mt.Mi[mk]
case m.(map[string][]string):
val, ok =
mt.Mi[mk]
case m.(map[string]map[string]interface{}):
val, ok =
mt.Mi[mk]
}
But, you are working against the language. Why not just require a method `Get(k
string) (interface{}, bool)` and use that?
val, ok := m.Get(mk)
On Mon, 2016-10-31 at 06:59 -0700, wwar...@gmail.com wrote:
> I'm new to Go, and I have a question about identifying types as
> they're
> encountered in traversing a map[string]interface{}.
>
> I've ended up with a big sieve of type assertions something like
> this:
>
> if mt.Mi, ok = m.(map[string]int); ok {
> nval, ok = mt.Mi[mk]
> } else if mt.MI, ok = m.(map[string]interface{}); ok {
> nval, ok = mt.MI[mk]
> } else if mt.Mai, ok = m.(map[string][]int); ok {
> nval, ok = mt.Mai[mk]
> } else if mt.Mas, ok = m.(map[string][]string); ok {
> nval, ok = mt.Mas[mk]
> } else if mt.Mmm, ok = m.(map[string]map[string]interface{});
> ok {
> nval, ok = mt.Mmm[mk]
>
> mt here is a struct that performs no work; it just associates a type
> to a
> name, so that the run-time can see the types of the left and the
> right
> sides of the assignment and determine if an assignment is possible.
> I
> really hate looking at that statement, but all my attempts at using
> reflection have failed as the compiler can't allocate with all the
> possible
> types that could be returned, even though in my application I only
> want to
> allocate for these five types. So that's my question: Can I DRY this
> up?
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
