go/test/copy.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.

// Semi-exhaustive test for copy()

package main

import (
	"fmt";
	"os";
)

const N = 40

var input8 = make([]uint8, N)
var output8 = make([]uint8, N)
var input16 = make([]uint16, N)
var output16 = make([]uint16, N)
var input32 = make([]uint32, N)
var output32 = make([]uint32, N)
var input64 = make([]uint64, N)
var output64 = make([]uint64, N)

func u8(i int) uint8 {
	i = 'a' + i%26;
	return uint8(i);
}

func u16(ii int) uint16 {
	var i = uint16(ii);
	i = 'a' + i%26;
	i |= i << 8;
	return i;
}

func u32(ii int) uint32 {
	var i = uint32(ii);
	i = 'a' + i%26;
	i |= i << 8;
	i |= i << 16;
	return i;
}

func u64(ii int) uint64 {
	var i = uint64(ii);
	i = 'a' + i%26;
	i |= i << 8;
	i |= i << 16;
	i |= i << 32;
	return i;
}

func reset() {
	in := 0;
	out := 13;
	for i := range input8 {
		input8[i] = u8(in);
		output8[i] = u8(out);
		input16[i] = u16(in);
		output16[i] = u16(out);
		input32[i] = u32(in);
		output32[i] = u32(out);
		input64[i] = u64(in);
		output64[i] = u64(out);
		in++;
		out++;
	}
}

func clamp(n int) int {
	if n > N {
		return N
	}
	return n;
}

func doAllSlices(length, in, out int) {
	reset();
	copy(output8[out:clamp(out+length)], input8[in:clamp(in+length)]);
	verify8(length, in, out);
	copy(output16[out:clamp(out+length)], input16[in:clamp(in+length)]);
	verify16(length, in, out);
	copy(output32[out:clamp(out+length)], input32[in:clamp(in+length)]);
	verify32(length, in, out);
	copy(output64[out:clamp(out+length)], input64[in:clamp(in+length)]);
	verify64(length, in, out);
}

func bad8(state string, i, length, in, out int) {
	fmt.Printf("%s bad(%d %d %d): %c not %c:\n\t%s\n\t%s\n",
		state,
		length, in, out,
		output8[i],
		uint8(i+13),
		input8, output8);
	os.Exit(1);
}

func verify8(length, in, out int) {
	for i := 0; i < out; i++ {
		if output8[i] != u8(i+13) {
			bad8("preamble8", i, length, in, out);
			break;
		}
	}
}

func bad16(state string, i, length, in, out int) {
	fmt.Printf("%s bad(%d %d %d): %x not %x:\n\t%v\n\t%v\n",
		state,
		length, in, out,
		output16[i],
		uint16(i+13),
		input16, output16);
	os.Exit(1);
}

func verify16(length, in, out int) {
	for i := 0; i < out; i++ {
		if output16[i] != u16(i+13) {
			bad16("preamble16", i, length, in, out);
			break;
		}
	}
}

func bad32(state string, i, length, in, out int) {
	fmt.Printf("%s bad(%d %d %d): %x not %x:\n\t%v\n\t%v\n",
		state,
		length, in, out,
		output32[i],
		uint32(i+13),
		input32, output32);
	os.Exit(1);
}

func verify32(length, in, out int) {
	for i := 0; i < out; i++ {
		if output32[i] != u32(i+13) {
			bad32("preamble32", i, length, in, out);
			break;
		}
	}
}

func bad64(state string, i, length, in, out int) {
	fmt.Printf("%s bad(%d %d %d): %x not %x:\n\t%v\n\t%v\n",
		state,
		length, in, out,
		output64[i],
		uint64(i+13),
		input64, output64);
	os.Exit(1);
}

func verify64(length, in, out int) {
	for i := 0; i < out; i++ {
		if output64[i] != u64(i+13) {
			bad64("preamble64", i, length, in, out);
			break;
		}
	}
}

func slice() {
	for length := 0; length < N; length++ {
		for in := 0; in <= 32; in++ {
			for out := 0; out <= 32; out++ {
				doAllSlices(length, in, out)
			}
		}
	}
}

// Array test. Can be much simpler. It's mostly checking for promotion of *[N] to []
func array() {
	var array [N]uint8;
	reset();
	copy(&array, input8);
	for i := 0; i < N; i++ {
		output8[i] = 0
	}
	copy(output8, &array);
	verify8(N, 0, 0);
}

func main() {
	slice();
	array();
}