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builtin: add string.len_utf8() method (#14208)

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StunxFS 2022-04-29 03:23:57 -04:00 committed by GitHub
parent 8b798acadd
commit 995485c649
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4 changed files with 33 additions and 12 deletions

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@ -295,6 +295,17 @@ pub fn (cp &char) vstring_literal_with_len(len int) string {
}
}
// len_utf8 returns the number of runes contained in the string `s`.
pub fn (s string) len_utf8() int {
mut l := 0
mut i := 0
for i < s.len {
l++
i += ((0xe5000000 >> ((unsafe { s.str[i] } >> 3) & 0x1e)) & 3) + 1
}
return l
}
// clone_static returns an independent copy of a given array.
// It should be used only in -autofree generated code.
fn (a string) clone_static() string {

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@ -24,6 +24,14 @@ fn test_add() {
assert a.ends_with('3')
}
fn test_len_utf8() {
assert 'Vlang'.len_utf8() == 5
assert 'María'.len_utf8() == 5
assert ''.len_utf8() == 2
assert 'Слово'.len_utf8() == 5
assert 'Λέξη'.len_utf8() == 4
}
fn test_ends_with() {
a := 'browser.v'
assert a.ends_with('.v')

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@ -66,6 +66,19 @@ pub fn utf32_decode_to_buffer(code u32, buf &u8) int {
return 0
}
// utf8_str_len returns the number of runes contained in the string.
[deprecated: 'use `string.len_utf8()` instead']
[deprecated_after: '2022-05-28']
pub fn utf8_str_len(s string) int {
mut l := 0
mut i := 0
for i < s.len {
l++
i += ((0xe5000000 >> ((unsafe { s.str[i] } >> 3) & 0x1e)) & 3) + 1
}
return l
}
// Convert utf8 to utf32
// the original implementation did not check for
// valid utf8 in the string, and could result in
@ -134,17 +147,6 @@ fn utf8_len(c u8) int {
return b
}
// Calculate string length for in number of codepoints
pub fn utf8_str_len(s string) int {
mut l := 0
mut i := 0
for i < s.len {
l++
i += ((0xe5000000 >> ((unsafe { s.str[i] } >> 3) & 0x1e)) & 3) + 1
}
return l
}
// Calculate string length for formatting, i.e. number of "characters"
// This is simplified implementation. if you need specification compliant width,
// use utf8.east_asian.display_width.

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@ -3143,7 +3143,7 @@ fn (mut g Gen) char_literal(node ast.CharLiteral) {
return
}
// TODO: optimize use L-char instead of u32 when possible
if utf8_str_len(node.val) < node.val.len {
if node.val.len_utf8() < node.val.len {
g.write('((rune)0x$node.val.utf32_code().hex() /* `$node.val` */)')
return
}