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// Copyright 2014 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 triegen_test
import (
"fmt"
"io"
"math/rand"
"unicode"
"golang.org/x/text/internal/triegen"
)
const seed = 0x12345
var genWriter = io.Discard
func randomRunes() map[rune]uint8 {
rnd := rand.New(rand.NewSource(seed))
m := map[rune]uint8{}
for len(m) < 100 {
// Only set our random rune if it is a valid Unicode code point.
if r := rune(rnd.Int31n(unicode.MaxRune + 1)); []rune(string(r))[0] == r {
m[r] = 1
}
}
return m
}
// Example_build shows how to build a simple trie. It assigns the value 1 to
// 100 random runes generated by randomRunes.
func Example_build() {
t := triegen.NewTrie("rand")
for r, _ := range randomRunes() {
t.Insert(r, 1)
}
sz, err := t.Gen(genWriter)
fmt.Printf("Trie size: %d bytes\n", sz)
fmt.Printf("Error: %v\n", err)
// Output:
// Trie size: 9280 bytes
// Error: <nil>
}
// Example_lookup demonstrates how to use the trie generated by Example_build.
func Example_lookup() {
trie := newRandTrie(0)
// The same set of runes used by Example_build.
runes := randomRunes()
// Verify the right value is returned for all runes.
for r := rune(0); r <= unicode.MaxRune; r++ {
// Note that the return type of lookup is uint8.
if v, _ := trie.lookupString(string(r)); v != runes[r] {
fmt.Println("FAILURE")
return
}
}
fmt.Println("SUCCESS")
// Output:
// SUCCESS
}
// runeValues generates some random values for a set of interesting runes.
func runeValues() map[rune]uint64 {
rnd := rand.New(rand.NewSource(seed))
m := map[rune]uint64{}
for p := 4; p <= unicode.MaxRune; p <<= 1 {
for d := -1; d <= 1; d++ {
m[rune(p+d)] = uint64(rnd.Int63())
}
}
return m
}
// ExampleGen_build demonstrates the creation of multiple tries sharing common
// blocks. ExampleGen_lookup demonstrates how to use the generated tries.
func ExampleGen_build() {
var tries []*triegen.Trie
rv := runeValues()
for _, c := range []struct {
include func(rune) bool
name string
}{
{func(r rune) bool { return true }, "all"},
{func(r rune) bool { return r < 0x80 }, "ASCII only"},
{func(r rune) bool { return r < 0x80 }, "ASCII only 2"},
{func(r rune) bool { return r <= 0xFFFF }, "BMP only"},
{func(r rune) bool { return r > 0xFFFF }, "No BMP"},
} {
t := triegen.NewTrie(c.name)
tries = append(tries, t)
for r, v := range rv {
if c.include(r) {
t.Insert(r, v)
}
}
}
sz, err := triegen.Gen(genWriter, "multi", tries)
fmt.Printf("Trie size: %d bytes\n", sz)
fmt.Printf("Error: %v\n", err)
// Output:
// Trie size: 18250 bytes
// Error: <nil>
}
// ExampleGen_lookup shows how to look up values in the trie generated by
// ExampleGen_build.
func ExampleGen_lookup() {
rv := runeValues()
for i, include := range []func(rune) bool{
func(r rune) bool { return true }, // all
func(r rune) bool { return r < 0x80 }, // ASCII only
func(r rune) bool { return r < 0x80 }, // ASCII only 2
func(r rune) bool { return r <= 0xFFFF }, // BMP only
func(r rune) bool { return r > 0xFFFF }, // No BMP
} {
t := newMultiTrie(i)
for r := rune(0); r <= unicode.MaxRune; r++ {
x := uint64(0)
if include(r) {
x = rv[r]
}
// As we convert from a valid rune, we know it is safe to use
// lookupStringUnsafe.
if v := t.lookupStringUnsafe(string(r)); x != v {
fmt.Println("FAILURE")
return
}
}
}
fmt.Println("SUCCESS")
// Output:
// SUCCESS
}