Vendor main dependencies.

vendor/github.com/BurntSushi/ty/fun/func.go

@@ -0,0 +1,35 @@
+package fun
+
+import (
+	"reflect"
+
+	"github.com/BurntSushi/ty"
+)
+
+// 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)),
+		f)
+	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()
+}