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v/vlib/builtin/utf8.v
2019-07-23 23:40:24 +02:00

134 lines
4.0 KiB
Go

// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module builtin
pub fn utf8_char_len(b byte) int {
return (( 0xe5000000 >> (( b >> 3 ) & 0x1e )) & 3 ) + 1
}
// Convert utf32 to utf8
// utf32 == Codepoint
pub fn utf32_to_str(code u32) string {
icode := int(code) //Prevents doing casts everywhere
mut buffer := malloc(5)
if icode <= 127 /* 0x7F */ {
buffer[0] = icode
return tos(buffer, 1)
}
if (icode <= 2047 /* 0x7FF */) {
buffer[0] = 192 /*0xC0*/ | (icode >> 6) /* 110xxxxx */
buffer[1] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 2)
}
if (icode <= 65535 /* 0xFFFF */) {
buffer[0] = 224 /*0xE0*/ | (icode >> 12) /* 1110xxxx */
buffer[1] = 128 /*0x80*/ | ((icode >> 6) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[2] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 3)
}
if (icode <= 1114111 /* 0x10FFFF */) {
buffer[0] = 240 /*0xF0*/ | (icode >> 18) /* 11110xxx */
buffer[1] = 128 /*0x80*/ | ((icode >> 12) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[2] = 128 /*0x80*/ | ((icode >> 6) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[3] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 4)
}
return ''
}
// TODO copypasta
pub fn utf32_to_str_no_malloc(code u32, buf voidptr) string {
icode := int(code) //Prevents doing casts everywhere
mut buffer := byteptr(buf)
if icode <= 127 /* 0x7F */ {
buffer[0] = icode
return tos(buffer, 1)
}
if (icode <= 2047 /* 0x7FF */) {
buffer[0] = 192 /*0xC0*/ | (icode >> 6) /* 110xxxxx */
buffer[1] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 2)
}
if (icode <= 65535 /* 0xFFFF */) {
buffer[0] = 224 /*0xE0*/ | (icode >> 12) /* 1110xxxx */
buffer[1] = 128 /*0x80*/ | ((icode >> 6) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[2] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 3)
}
if (icode <= 1114111 /* 0x10FFFF */) {
buffer[0] = 240 /*0xF0*/ | (icode >> 18) /* 11110xxx */
buffer[1] = 128 /*0x80*/ | ((icode >> 12) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[2] = 128 /*0x80*/ | ((icode >> 6) & 63 /*0x3F*/) /* 10xxxxxx */
buffer[3] = 128 /*0x80*/ | (icode & 63 /*0x3F*/) /* 10xxxxxx */
return tos(buffer, 4)
}
return ''
}
// Convert utf8 to utf32
pub fn (_rune string) utf32_code() int {
if _rune.len == 0 {
return 0
}
// save ASC symbol as is
if _rune.len == 1 {
return int(_rune[0])
}
mut b := byte(int(_rune[0]))
// TODO should be
// res := int( rune[0] << rune.len)
b = b << _rune.len
mut res := int(b)
mut shift := 6 - _rune.len
for i := 1; i < _rune.len; i++ {
c := int(_rune[i])
res = res << shift
res |= c & 63 /* 0x3f */
shift = 6
}
return res
}
const (
CP_UTF8 = 65001
)
pub fn (_str string) to_wide() &u16 {
$if windows {
num_chars := int(C.MultiByteToWideChar(CP_UTF8, 0, _str.str, _str.len, 0, 0))
mut wstr := &u16(malloc((num_chars + 1) * 2)) // sizeof(wchar_t)
if wstr > 0 {
C.MultiByteToWideChar(CP_UTF8, 0, _str.str, _str.len, wstr, num_chars)
C.memset(&byte(wstr) + num_chars * 2, 0, 2)
}
return wstr
} $else {
return 0
}
}
pub fn string_from_wide(_wstr &u16) string {
$if windows {
wstr_len := int(C.wcslen(_wstr))
return string_from_wide2(_wstr, wstr_len)
} $else {
return ''
}
}
pub fn string_from_wide2(_wstr &u16, len int) string {
$if windows {
num_chars := int(C.WideCharToMultiByte(CP_UTF8, 0, _wstr, len, 0, 0, 0, 0))
mut str_to := &byte(malloc(num_chars + 1))
if str_to > 0 {
C.WideCharToMultiByte(CP_UTF8, 0, _wstr, len, str_to, num_chars, 0, 0)
C.memset(&byte(str_to) + num_chars, 0, 1)
}
return tos2(str_to)
} $else {
return ''
}
}