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v/vlib/strings/strings.c.v

41 lines
937 B
V

module strings
// strings.repeat - fill a string with `n` repetitions of the character `c`
[direct_array_access]
pub fn repeat(c u8, n int) string {
if n <= 0 {
return ''
}
mut bytes := unsafe { malloc_noscan(n + 1) }
unsafe {
C.memset(bytes, c, n)
bytes[n] = `0`
}
return unsafe { bytes.vstring_with_len(n) }
}
// strings.repeat_string - gives you `n` repetitions of the substring `s`
// Note: strings.repeat, that repeats a single byte, is between 2x
// and 24x faster than strings.repeat_string called for a 1 char string.
[direct_array_access]
pub fn repeat_string(s string, n int) string {
if n <= 0 || s.len == 0 {
return ''
}
slen := s.len
blen := slen * n
mut bytes := unsafe { malloc_noscan(blen + 1) }
for bi in 0 .. n {
bislen := bi * slen
for si in 0 .. slen {
unsafe {
bytes[bislen + si] = s[si]
}
}
}
unsafe {
bytes[blen] = `0`
}
return unsafe { bytes.vstring_with_len(blen) }
}