func_sub.go

package fgbase

import (
	"reflect"
)

func subFire2(a, b interface{}) interface{} {

	switch a.(type) {
	case int8:
		{
			return a.(int8) - b.(int8)
		}
	case uint8:
		{
			return a.(uint8) - b.(uint8)
		}
	case int16:
		{
			return a.(int16) - b.(int16)
		}
	case uint16:
		{
			return a.(uint16) - b.(uint16)
		}
	case int32:
		{
			return a.(int32) - b.(int32)
		}
	case uint32:
		{
			return a.(uint32) - b.(uint32)
		}
	case int64:
		{
			return a.(int64) - b.(int64)
		}
	case uint64:
		{
			return a.(uint64) - b.(uint64)
		}
	case int:
		{
			return a.(int) - b.(int)
		}
	case uint:
		{
			return a.(uint) - b.(uint)
		}
	case float32:
		{
			return a.(float32) - b.(float32)
		}
	case float64:
		{
			return a.(float64) - b.(float64)
		}
	case complex64:
		{
			return a.(complex64) - b.(complex64)
		}
	case complex128:
		{
			return a.(complex128) - b.(complex128)
		}
	default:
		{
			return nil
		}
	}
}

// SubFire is fire func for FuncFire
func SubFire(n *Node) error {
	a := n.Srcs[0]
	b := n.Srcs[1]
	x := n.Dsts[0]

	av := a.SrcGet()
	bv := b.SrcGet()
	if IsEOF(av) || IsEOF(bv) {
		x.DstPut(EOF)
		return EOF
	}

	atmp, btmp, same := Promote(n, av, bv)

	if !same {
		n.LogError("incompatible types for subtraction (%v-%v)", reflect.TypeOf(a.Val), reflect.TypeOf(b.Val))
		x.DstPut(nil)
	} else {

		x.DstPut(subFire2(atmp, btmp))
	}
	return nil
}

// FuncSub subtracts values and returns the difference (x = a - b).
func FuncSub(a, b, x Edge) Node {

	node := MakeNode("sub", []*Edge{&a, &b}, []*Edge{&x}, nil, SubFire)
	return node
}