libgo/go/golang_org/x/text/unicode/norm/trie.go

   1 // Code generated by running "go run gen.go -core" in golang.org/x/text. DO NOT EDIT.
   2
   3 // Copyright 2011 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 package norm
   8
   9 type valueRange struct {
  10         value  uint16 // header: value:stride
  11         lo, hi byte   // header: lo:n
  12 }
  13
  14 type sparseBlocks struct {
  15         values []valueRange
  16         offset []uint16
  17 }
  18
  19 var nfcSparse = sparseBlocks{
  20         values: nfcSparseValues[:],
  21         offset: nfcSparseOffset[:],
  22 }
  23
  24 var nfkcSparse = sparseBlocks{
  25         values: nfkcSparseValues[:],
  26         offset: nfkcSparseOffset[:],
  27 }
  28
  29 var (
  30         nfcData  = newNfcTrie(0)
  31         nfkcData = newNfkcTrie(0)
  32 )
  33
  34 // lookupValue determines the type of block n and looks up the value for b.
  35 // For n < t.cutoff, the block is a simple lookup table. Otherwise, the block
  36 // is a list of ranges with an accompanying value. Given a matching range r,
  37 // the value for b is by r.value + (b - r.lo) * stride.
  38 func (t *sparseBlocks) lookup(n uint32, b byte) uint16 {
  39         offset := t.offset[n]
  40         header := t.values[offset]
  41         lo := offset + 1
  42         hi := lo + uint16(header.lo)
  43         for lo < hi {
  44                 m := lo + (hi-lo)/2
  45                 r := t.values[m]
  46                 if r.lo <= b && b <= r.hi {
  47                         return r.value + uint16(b-r.lo)*header.value
  48                 }
  49                 if b < r.lo {
  50                         hi = m
  51                 } else {
  52                         lo = m + 1
  53                 }
  54         }
  55         return 0
  56 }