Support more than 3 types

[schancel]

Should support more than 3 types. They could be defined in the go generic source via:

type Param generic.Type;

The gengen.go could scan the file for these top-level decls and add them to generic types.

If you'd accept a PR for this, I could do it probably.

[joeshaw]

Sure, I'd be happy to accept a PR for this.

[ghost]

whatever happened with this idea?

[joeshaw]

I'd still like to do this at some point, but it hasn't been an issue for me thus far. The command-line should probably take key/value arguments to support this. Something like:

$ gengen github.com/example/foo Param=int

If the key (Param) isn't provided it'd still work with generic.T et al for backward compatibility.

[ghost]

The 'key=value' syntax seems good to me. :)

[james-lawrence]

I'd like to see something like this (just to have explicit examples, I think I'm in agreement with schancel):

type Value gengen.Generic

type SortedSet interface {
  Insert(Value) bool
  Remove(value) bool
  Pop() Value
}

func NewSortedSet(comparator func(a, b Value) int) SortedSet { ... }

// go:generate gengen github.com/example/SortedSet Value=int
// would result in the following code:
type SortedSet interface {
  Insert(int) bool
  Remove(int) bool
  Pop() int
}

func NewSortedSet(comparator func(a, b int) int) SortedSet { ... }

// go:generate gengen github.com/example/SortedSet Value=string
// would result in the following code:
type SortedSet interface {
  Insert(string) bool
  Remove(string) bool
  Pop() string
}

func NewSortedSet(comparator func(a, b string) int) SortedSet { ... }

Multiple Generic Types example:

type Key gengen.Generic
type Value gengen.Generic

type Map interface {
  Insert(Key, Value) bool
  Delete(Key) bool
}

// go:generate gengen github.com/example/Map Key=int Value=string
// would result in the following code:
type Map interface {
  Insert(int, string) bool
  Delete(int) bool
}

This would support arbitrary number of polymorphic parameters, and be straight forward to use, can still leverage golang's ast package, and would still be valid go code.