add a new x/reflex sub-package for reflection common functions - may be improved in the near future

x/reflex/func.go

@@ -0,0 +1,44 @@
+package reflex
+
+import "reflect"
+
+// IsFunc reports whether the "kindable" is a type of function.
+func IsFunc(typ interface{ Kind() reflect.Kind }) bool {
+	return typ.Kind() == reflect.Func
+}
+
+// FuncParam holds the properties of function input or output.
+type FuncParam struct {
+	Index int
+	Type  reflect.Type
+}
+
+// LookupInputs returns the index and type of each function's input argument.
+// Panics if "fn" is not a type of Func.
+func LookupInputs(fn reflect.Type) []FuncParam {
+	n := fn.NumIn()
+	params := make([]FuncParam, 0, n)
+	for i := 0; i < n; i++ {
+		in := fn.In(i)
+		params = append(params, FuncParam{
+			Index: i,
+			Type:  in,
+		})
+	}
+	return params
+}
+
+// LookupOutputs returns the index and type of each function's output argument.
+// Panics if "fn" is not a type of Func.
+func LookupOutputs(fn reflect.Type) []FuncParam {
+	n := fn.NumOut()
+	params := make([]FuncParam, 0, n)
+	for i := 0; i < n; i++ {
+		out := fn.Out(i)
+		params = append(params, FuncParam{
+			Index: i,
+			Type:  out,
+		})
+	}
+	return params
+}