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