Hulk did something

[bytom/vapor.git] / vendor / golang.org / x / text / unicode / norm / trie.go

diff --git a/vendor/golang.org/x/text/unicode/norm/trie.go b/vendor/golang.org/x/text/unicode/norm/trie.go
new file mode 100644 (file)
index 0000000..423386b
--- /dev/null
+++ b/vendor/golang.org/x/text/unicode/norm/trie.go
@@ -0,0 +1,54 @@
+// Copyright 2011 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 norm
+
+type valueRange struct {
+       value  uint16 // header: value:stride
+       lo, hi byte   // header: lo:n
+}
+
+type sparseBlocks struct {
+       values []valueRange
+       offset []uint16
+}
+
+var nfcSparse = sparseBlocks{
+       values: nfcSparseValues[:],
+       offset: nfcSparseOffset[:],
+}
+
+var nfkcSparse = sparseBlocks{
+       values: nfkcSparseValues[:],
+       offset: nfkcSparseOffset[:],
+}
+
+var (
+       nfcData  = newNfcTrie(0)
+       nfkcData = newNfkcTrie(0)
+)
+
+// lookupValue determines the type of block n and looks up the value for b.
+// For n < t.cutoff, the block is a simple lookup table. Otherwise, the block
+// is a list of ranges with an accompanying value. Given a matching range r,
+// the value for b is by r.value + (b - r.lo) * stride.
+func (t *sparseBlocks) lookup(n uint32, b byte) uint16 {
+       offset := t.offset[n]
+       header := t.values[offset]
+       lo := offset + 1
+       hi := lo + uint16(header.lo)
+       for lo < hi {
+               m := lo + (hi-lo)/2
+               r := t.values[m]
+               if r.lo <= b && b <= r.hi {
+                       return r.value + uint16(b-r.lo)*header.value
+               }
+               if b < r.lo {
+                       hi = m
+               } else {
+                       lo = m + 1
+               }
+       }
+       return 0
+}