Skip to content
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
Cannot retrieve contributors at this time
package fun
import (
// Memo has a parametric type:
// func Memo(f func(A) B) func(A) B
// Memo memoizes any function of a single argument that returns a single value.
// The type `A` must be a Go type for which the comparison operators `==` and
// `!=` are fully defined (this rules out functions, maps and slices).
func Memo(f interface{}) interface{} {
chk := ty.Check(
new(func(func(ty.A) ty.B)),
vf := chk.Args[0]
saved := make(map[interface{}]reflect.Value)
memo := func(in []reflect.Value) []reflect.Value {
val := in[0].Interface()
ret, ok := saved[val]
if ok {
return []reflect.Value{ret}
ret = call1(vf, in[0])
saved[val] = ret
return []reflect.Value{ret}
return reflect.MakeFunc(vf.Type(), memo).Interface()