nextafter.go

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package math32

// Nextafter returns the next representable float32 value after x towards y.
//
// Special cases are:
//	Nextafter32(x, x)   = x
//	Nextafter32(NaN, y) = NaN
//	Nextafter32(x, NaN) = NaN
func Nextafter(x, y float32) (r float32) {
	switch {
	case IsNaN(x) || IsNaN(y): // special case
		r = float32(NaN())
	case x == y:
		r = x
	case x == 0:
		r = float32(Copysign(Float32frombits(1), y))
	case (y > x) == (x > 0):
		r = Float32frombits(Float32bits(x) + 1)
	default:
		r = Float32frombits(Float32bits(x) - 1)
	}
	return
}