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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"
"io/ioutil"
"golang.org/x/text/internal/triegen"
)
func ExampleCompacter() {
t := triegen.NewTrie("root")
for r := rune(0); r < 10000; r += 64 {
t.Insert(r, 0x9015BADA55^uint64(r))
}
sz, _ := t.Gen(ioutil.Discard)
fmt.Printf("Size normal: %5d\n", sz)
var c myCompacter
sz, _ = t.Gen(ioutil.Discard, triegen.Compact(&c))
fmt.Printf("Size compacted: %5d\n", sz)
// Output:
// Size normal: 81344
// Size compacted: 3224
}
// A myCompacter accepts a block if only the first value is given.
type myCompacter []uint64
func (c *myCompacter) Size(values []uint64) (sz int, ok bool) {
for _, v := range values[1:] {
if v != 0 {
return 0, false
}
}
return 8, true // the size of a uint64
}
func (c *myCompacter) Store(v []uint64) uint32 {
x := uint32(len(*c))
*c = append(*c, v[0])
return x
}
func (c *myCompacter) Print(w io.Writer) error {
fmt.Fprintln(w, "var firstValue = []uint64{")
for _, v := range *c {
fmt.Fprintf(w, "\t%#x,\n", v)
}
fmt.Fprintln(w, "}")
return nil
}
func (c *myCompacter) Handler() string {
return "getFirstValue"
// Where getFirstValue is included along with the generated code:
// func getFirstValue(n uint32, b byte) uint64 {
// if b == 0x80 { // the first continuation byte
// return firstValue[n]
// }
// return 0
// }
}
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