1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
// SPDX-License-Identifier: MPL-2.0
// (c) Hare authors <https://harelang.org>
use encoding::utf8;
// Pads the start of a string 's' with rune 'p' until the string reaches length
// 'maxlen'. The caller must free the return value.
export fn lpad(s: str, p: rune, maxlen: size) (str | nomem) = {
if (len(s) >= maxlen) {
return dup(s)?;
};
let res: []u8 = alloc([], maxlen)!;
let ok = false;
defer if (!ok) free(res);
for (let i = 0z; i < maxlen - len(s); i += 1) {
append(res, utf8::encoderune(p)...)?;
};
append(res, toutf8(s)...)?;
ok = true;
return fromutf8_unsafe(res[..maxlen]);
};
@test fn lpad() void = {
let s = lpad("2", '0', 5)!;
assert(s == "00002");
free(s);
let s = lpad("12345", '0', 5)!;
assert(s == "12345");
free(s);
let s = lpad("", '0', 5)!;
assert(s == "00000");
free(s);
};
// Pads the end of a string 's' with rune 'p' until the string reaches length
// 'maxlen'. The caller must free the return value.
export fn rpad(s: str, p: rune, maxlen: size) (str | nomem) = {
if (len(s) >= maxlen) {
return dup(s)?;
};
let res: []u8 = alloc([], maxlen)!;
let ok = false;
defer if (!ok) free(res);
append(res, toutf8(s)...)!;
for (let i = 0z; i < maxlen - len(s); i += 1) {
append(res, utf8::encoderune(p)...)!;
};
ok = true;
return fromutf8_unsafe(res[..maxlen]);
};
@test fn rpad() void = {
let s = rpad("2", '0', 5)!;
assert(s == "20000");
free(s);
let s = rpad("12345", '0', 5)!;
assert(s == "12345");
free(s);
let s = rpad("", '0', 5)!;
assert(s == "00000");
free(s);
};
|
