go/test/const.go

// $G $F.go && $L $F.$A && ./$A.out

// Copyright 2009 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 main

const (
	c0 = 0
	cm1 = -1
	chuge = 1 << 100
	chuge_1 = chuge - 1
	c1 = chuge >> 100
	c3div2 = 3/2
	c1e3 = 1e3

	ctrue = true
	cfalse = !ctrue
)

const (
	f0 = 0.0
	fm1 = -1.
	fhuge float64 = 1 << 100
	fhuge_1 float64 = chuge - 1
	f1 float64 = chuge >> 100
	f3div2 = 3./2.
	f1e3 float64 = 1e3
)

func assert(t bool, s string) {
	if !t {
		panic(s)
	}
}

func ints() {
	assert(c0 == 0, "c0")
	assert(c1 == 1, "c1")
	assert(chuge > chuge_1, "chuge")
	assert(chuge_1 + 1 == chuge, "chuge 1")
	assert(chuge + cm1 +1  == chuge, "cm1")
	assert(c3div2 == 1, "3/2")
	assert(c1e3 == 1000, "c1e3 int")
	assert(c1e3 == 1e3, "c1e3 float")

	// verify that all (in range) are assignable as ints
	var i int
	i = c0
	assert(i == c0, "i == c0")
	i = cm1
	assert(i == cm1, "i == cm1")
	i = c1
	assert(i == c1, "i == c1")
	i = c3div2
	assert(i == c3div2, "i == c3div2")
	i = c1e3
	assert(i == c1e3, "i == c1e3")

	// verify that all are assignable as floats
	var f float64
	f = c0
	assert(f == c0, "f == c0")
	f = cm1
	assert(f == cm1, "f == cm1")
	f = chuge
	assert(f == chuge, "f == chuge")
	f = chuge_1
	assert(f == chuge_1, "f == chuge_1")
	f = c1
	assert(f == c1, "f == c1")
	f = c3div2
	assert(f == c3div2, "f == c3div2")
	f = c1e3
	assert(f == c1e3, "f == c1e3")
}

func floats() {
	assert(f0 == c0, "f0")
	assert(f1 == c1, "f1")
	assert(fhuge == fhuge_1, "fhuge")	// float64 can't distinguish fhuge, fhuge_1.
	assert(fhuge_1 + 1 == fhuge, "fhuge 1")
	assert(fhuge + fm1 +1  == fhuge, "fm1")
	assert(f3div2 == 1.5, "3./2.")
	assert(f1e3 == 1000, "f1e3 int")
	assert(f1e3 == 1.e3, "f1e3 float")

	// verify that all (in range) are assignable as ints
	var i int
	i = f0
	assert(i == f0, "i == f0")
	i = fm1
	assert(i == fm1, "i == fm1")

	// verify that all are assignable as floats
	var f float64
	f = f0
	assert(f == f0, "f == f0")
	f = fm1
	assert(f == fm1, "f == fm1")
	f = fhuge
	assert(f == fhuge, "f == fhuge")
	f = fhuge_1
	assert(f == fhuge_1, "f == fhuge_1")
	f = f1
	assert(f == f1, "f == f1")
	f = f3div2
	assert(f == f3div2, "f == f3div2")
	f = f1e3
	assert(f == f1e3, "f == f1e3")
}

func main() {
	ints()
	floats()

	assert(ctrue == true, "ctrue == true")
	assert(cfalse == false, "cfalse == false")
}