github.com/go-xe2/third@v1.0.3/golang.org/x/text/unicode/runenames/runenames.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:generate go run gen.go gen_bits.go
     6  
     7  // Package runenames provides rune names from the Unicode Character Database.
     8  // For example, the name for '\u0100' is "LATIN CAPITAL LETTER A WITH MACRON".
     9  //
    10  // See http://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt
    11  package runenames
    12  
    13  import (
    14  	"sort"
    15  )
    16  
    17  // Name returns the name for r.
    18  func Name(r rune) string {
    19  	i := sort.Search(len(table0), func(j int) bool {
    20  		e := table0[j]
    21  		rOffset := rune(e >> shiftRuneOffset)
    22  		return r < rOffset
    23  	})
    24  	if i == 0 {
    25  		return ""
    26  	}
    27  
    28  	e := table0[i-1]
    29  	rOffset := rune(e >> shiftRuneOffset)
    30  	rLength := rune(e>>shiftRuneLength) & maskRuneLength
    31  	if r >= rOffset+rLength {
    32  		return ""
    33  	}
    34  
    35  	if (e>>shiftDirect)&maskDirect != 0 {
    36  		o := int(e>>shiftDataOffset) & maskDataOffset
    37  		n := int(e>>shiftDataLength) & maskDataLength
    38  		return data[o : o+n]
    39  	}
    40  
    41  	base := uint32(e>>shiftDataBase) & maskDataBase
    42  	base <<= dataBaseUnit
    43  	j := rune(e>>shiftTable1Offset) & maskTable1Offset
    44  	j += r - rOffset
    45  	d0 := base + uint32(table1[j-1]) // dataOffset
    46  	d1 := base + uint32(table1[j-0]) // dataOffset + dataLength
    47  	return data[d0:d1]
    48  }