Files
Odin/core/bytes/bytes.odin

1128 lines
21 KiB
Odin

package bytes
import "core:mem"
import "core:unicode"
import "core:unicode/utf8"
clone :: proc(s: []byte, allocator := context.allocator, loc := #caller_location) -> []byte {
c := make([]byte, len(s)+1, allocator, loc);
copy(c, s);
c[len(s)] = 0;
return c[:len(s)];
}
ptr_from_slice :: proc(str: []byte) -> ^byte {
d := transmute(mem.Raw_String)str;
return d.data;
}
// Compares two strings, returning a value representing which one comes first lexiographically.
// -1 for `a`; 1 for `b`, or 0 if they are equal.
compare :: proc(lhs, rhs: []byte) -> int {
return mem.compare(lhs, rhs);
}
contains_rune :: proc(s: []byte, r: rune) -> int {
for c, offset in string(s) {
if c == r {
return offset;
}
}
return -1;
}
contains :: proc(s, substr: []byte) -> bool {
return index(s, substr) >= 0;
}
contains_any :: proc(s, chars: []byte) -> bool {
return index_any(s, chars) >= 0;
}
rune_count :: proc(s: []byte) -> int {
return utf8.rune_count(s);
}
equal :: proc(a, b: []byte) -> bool {
return string(a) == string(b);
}
equal_fold :: proc(u, v: []byte) -> bool {
s, t := string(u), string(v);
loop: for s != "" && t != "" {
sr, tr: rune;
if s[0] < utf8.RUNE_SELF {
sr, s = rune(s[0]), s[1:];
} else {
r, size := utf8.decode_rune_in_string(s);
sr, s = r, s[size:];
}
if t[0] < utf8.RUNE_SELF {
tr, t = rune(t[0]), t[1:];
} else {
r, size := utf8.decode_rune_in_string(t);
tr, t = r, t[size:];
}
if tr == sr { // easy case
continue loop;
}
if tr < sr {
tr, sr = sr, tr;
}
if tr < utf8.RUNE_SELF {
switch sr {
case 'A'..'Z':
if tr == (sr+'a')-'A' {
continue loop;
}
}
return false;
}
// TODO(bill): Unicode folding
return false;
}
return s == t;
}
has_prefix :: proc(s, prefix: []byte) -> bool {
return len(s) >= len(prefix) && string(s[0:len(prefix)]) == string(prefix);
}
has_suffix :: proc(s, suffix: []byte) -> bool {
return len(s) >= len(suffix) && string(s[len(s)-len(suffix):]) == string(suffix);
}
join :: proc(a: [][]byte, sep: []byte, allocator := context.allocator) -> []byte {
if len(a) == 0 {
return nil;
}
n := len(sep) * (len(a) - 1);
for s in a {
n += len(s);
}
b := make([]byte, n, allocator);
i := copy(b, a[0]);
for s in a[1:] {
i += copy(b[i:], sep);
i += copy(b[i:], s);
}
return b;
}
concatenate :: proc(a: [][]byte, allocator := context.allocator) -> []byte {
if len(a) == 0 {
return nil;
}
n := 0;
for s in a {
n += len(s);
}
b := make([]byte, n, allocator);
i := 0;
for s in a {
i += copy(b[i:], s);
}
return b;
}
@private
_split :: proc(s, sep: []byte, sep_save, n: int, allocator := context.allocator) -> [][]byte {
s, n := s, n;
if n == 0 {
return nil;
}
if sep == nil {
l := utf8.rune_count(s);
if n < 0 || n > l {
n = l;
}
res := make([dynamic][]byte, n, allocator);
for i := 0; i < n-1; i += 1 {
_, w := utf8.decode_rune(s);
res[i] = s[:w];
s = s[w:];
}
if n > 0 {
res[n-1] = s;
}
return res[:];
}
if n < 0 {
n = count(s, sep) + 1;
}
res := make([dynamic][]byte, n, allocator);
n -= 1;
i := 0;
for ; i < n; i += 1 {
m := index(s, sep);
if m < 0 {
break;
}
res[i] = s[:m+sep_save];
s = s[m+len(sep):];
}
res[i] = s;
return res[:i+1];
}
split :: proc(s, sep: []byte, allocator := context.allocator) -> [][]byte {
return _split(s, sep, 0, -1, allocator);
}
split_n :: proc(s, sep: []byte, n: int, allocator := context.allocator) -> [][]byte {
return _split(s, sep, 0, n, allocator);
}
split_after :: proc(s, sep: []byte, allocator := context.allocator) -> [][]byte {
return _split(s, sep, len(sep), -1, allocator);
}
split_after_n :: proc(s, sep: []byte, n: int, allocator := context.allocator) -> [][]byte {
return _split(s, sep, len(sep), n, allocator);
}
@private
_split_iterator :: proc(s: ^[]byte, sep: []byte, sep_save, n: int) -> (res: []byte, ok: bool) {
s, n := s, n;
if n == 0 {
return;
}
if sep == nil {
res = s[:];
ok = true;
s^ = s[len(s):];
return;
}
if n < 0 {
n = count(s^, sep) + 1;
}
n -= 1;
i := 0;
for ; i < n; i += 1 {
m := index(s^, sep);
if m < 0 {
break;
}
res = s[:m+sep_save];
ok = true;
s^ = s[m+len(sep):];
return;
}
res = s[:];
ok = res != nil;
s^ = s[len(s):];
return;
}
split_iterator :: proc(s: ^[]byte, sep: []byte) -> ([]byte, bool) {
return _split_iterator(s, sep, 0, -1);
}
split_n_iterator :: proc(s: ^[]byte, sep: []byte, n: int) -> ([]byte, bool) {
return _split_iterator(s, sep, 0, n);
}
split_after_iterator :: proc(s: ^[]byte, sep: []byte) -> ([]byte, bool) {
return _split_iterator(s, sep, len(sep), -1);
}
split_after_n_iterator :: proc(s: ^[]byte, sep: []byte, n: int) -> ([]byte, bool) {
return _split_iterator(s, sep, len(sep), n);
}
index_byte :: proc(s: []byte, c: byte) -> int {
for i := 0; i < len(s); i += 1 {
if s[i] == c {
return i;
}
}
return -1;
}
// Returns -1 if c is not present
last_index_byte :: proc(s: []byte, c: byte) -> int {
for i := len(s)-1; i >= 0; i -= 1 {
if s[i] == c {
return i;
}
}
return -1;
}
@private PRIME_RABIN_KARP :: 16777619;
index :: proc(s, substr: []byte) -> int {
hash_str_rabin_karp :: proc(s: []byte) -> (hash: u32 = 0, pow: u32 = 1) {
for i := 0; i < len(s); i += 1 {
hash = hash*PRIME_RABIN_KARP + u32(s[i]);
}
sq := u32(PRIME_RABIN_KARP);
for i := len(s); i > 0; i >>= 1 {
if (i & 1) != 0 {
pow *= sq;
}
sq *= sq;
}
return;
}
n := len(substr);
switch {
case n == 0:
return 0;
case n == 1:
return index_byte(s, substr[0]);
case n == len(s):
if string(s) == string(substr) {
return 0;
}
return -1;
case n > len(s):
return -1;
}
hash, pow := hash_str_rabin_karp(substr);
h: u32;
for i := 0; i < n; i += 1 {
h = h*PRIME_RABIN_KARP + u32(s[i]);
}
if h == hash && string(s[:n]) == string(substr) {
return 0;
}
for i := n; i < len(s); /**/ {
h *= PRIME_RABIN_KARP;
h += u32(s[i]);
h -= pow * u32(s[i-n]);
i += 1;
if h == hash && string(s[i-n:i]) == string(substr) {
return i - n;
}
}
return -1;
}
last_index :: proc(s, substr: []byte) -> int {
hash_str_rabin_karp_reverse :: proc(s: []byte) -> (hash: u32 = 0, pow: u32 = 1) {
for i := len(s) - 1; i >= 0; i -= 1 {
hash = hash*PRIME_RABIN_KARP + u32(s[i]);
}
sq := u32(PRIME_RABIN_KARP);
for i := len(s); i > 0; i >>= 1 {
if (i & 1) != 0 {
pow *= sq;
}
sq *= sq;
}
return;
}
n := len(substr);
switch {
case n == 0:
return len(s);
case n == 1:
return last_index_byte(s, substr[0]);
case n == len(s):
return 0 if string(substr) == string(s) else -1;
case n > len(s):
return -1;
}
hash, pow := hash_str_rabin_karp_reverse(substr);
last := len(s) - n;
h: u32;
for i := len(s)-1; i >= last; i -= 1 {
h = h*PRIME_RABIN_KARP + u32(s[i]);
}
if h == hash && string(s[last:]) == string(substr) {
return last;
}
for i := last-1; i >= 0; i -= 1 {
h *= PRIME_RABIN_KARP;
h += u32(s[i]);
h -= pow * u32(s[i+n]);
if h == hash && string(s[i:i+n]) == string(substr) {
return i;
}
}
return -1;
}
index_any :: proc(s, chars: []byte) -> int {
if chars == nil {
return -1;
}
// TODO(bill): Optimize
for r, i in s {
for c in chars {
if r == c {
return i;
}
}
}
return -1;
}
last_index_any :: proc(s, chars: []byte) -> int {
if chars == nil {
return -1;
}
for i := len(s); i > 0; {
r, w := utf8.decode_last_rune(s[:i]);
i -= w;
for c in string(chars) {
if r == c {
return i;
}
}
}
return -1;
}
count :: proc(s, substr: []byte) -> int {
if len(substr) == 0 { // special case
return rune_count(s) + 1;
}
if len(substr) == 1 {
c := substr[0];
switch len(s) {
case 0:
return 0;
case 1:
return int(s[0] == c);
}
n := 0;
for i := 0; i < len(s); i += 1 {
if s[i] == c {
n += 1;
}
}
return n;
}
// TODO(bill): Use a non-brute for approach
n := 0;
str := s;
for {
i := index(str, substr);
if i == -1 {
return n;
}
n += 1;
str = str[i+len(substr):];
}
return n;
}
repeat :: proc(s: []byte, count: int, allocator := context.allocator) -> []byte {
if count < 0 {
panic("bytes: negative repeat count");
} else if count > 0 && (len(s)*count)/count != len(s) {
panic("bytes: repeat count will cause an overflow");
}
b := make([]byte, len(s)*count, allocator);
i := copy(b, s);
for i < len(b) { // 2^N trick to reduce the need to copy
copy(b[i:], b[:i]);
i *= 2;
}
return b;
}
replace_all :: proc(s, old, new: []byte, allocator := context.allocator) -> (output: []byte, was_allocation: bool) {
return replace(s, old, new, -1, allocator);
}
// if n < 0, no limit on the number of replacements
replace :: proc(s, old, new: []byte, n: int, allocator := context.allocator) -> (output: []byte, was_allocation: bool) {
if string(old) == string(new) || n == 0 {
was_allocation = false;
output = s;
return;
}
byte_count := n;
if m := count(s, old); m == 0 {
was_allocation = false;
output = s;
return;
} else if n < 0 || m < n {
byte_count = m;
}
t := make([]byte, len(s) + byte_count*(len(new) - len(old)), allocator);
was_allocation = true;
w := 0;
start := 0;
for i := 0; i < byte_count; i += 1 {
j := start;
if len(old) == 0 {
if i > 0 {
_, width := utf8.decode_rune(s[start:]);
j += width;
}
} else {
j += index(s[start:], old);
}
w += copy(t[w:], s[start:j]);
w += copy(t[w:], new);
start = j + len(old);
}
w += copy(t[w:], s[start:]);
output = t[0:w];
return;
}
@(private) _ascii_space := [256]u8{'\t' = 1, '\n' = 1, '\v' = 1, '\f' = 1, '\r' = 1, ' ' = 1};
is_ascii_space :: proc(r: rune) -> bool {
if r < utf8.RUNE_SELF {
return _ascii_space[u8(r)] != 0;
}
return false;
}
is_space :: proc(r: rune) -> bool {
if r < 0x2000 {
switch r {
case '\t', '\n', '\v', '\f', '\r', ' ', 0x85, 0xa0, 0x1680:
return true;
}
} else {
if r <= 0x200a {
return true;
}
switch r {
case 0x2028, 0x2029, 0x202f, 0x205f, 0x3000:
return true;
}
}
return false;
}
is_null :: proc(r: rune) -> bool {
return r == 0x0000;
}
index_proc :: proc(s: []byte, p: proc(rune) -> bool, truth := true) -> int {
for r, i in string(s) {
if p(r) == truth {
return i;
}
}
return -1;
}
index_proc_with_state :: proc(s: []byte, p: proc(rawptr, rune) -> bool, state: rawptr, truth := true) -> int {
for r, i in string(s) {
if p(state, r) == truth {
return i;
}
}
return -1;
}
last_index_proc :: proc(s: []byte, p: proc(rune) -> bool, truth := true) -> int {
// TODO(bill): Probably use Rabin-Karp Search
for i := len(s); i > 0; {
r, size := utf8.decode_last_rune(s[:i]);
i -= size;
if p(r) == truth {
return i;
}
}
return -1;
}
last_index_proc_with_state :: proc(s: []byte, p: proc(rawptr, rune) -> bool, state: rawptr, truth := true) -> int {
// TODO(bill): Probably use Rabin-Karp Search
for i := len(s); i > 0; {
r, size := utf8.decode_last_rune(s[:i]);
i -= size;
if p(state, r) == truth {
return i;
}
}
return -1;
}
trim_left_proc :: proc(s: []byte, p: proc(rune) -> bool) -> []byte {
i := index_proc(s, p, false);
if i == -1 {
return nil;
}
return s[i:];
}
index_rune :: proc(s: []byte, r: rune) -> int {
switch {
case 0 <= r && r < utf8.RUNE_SELF:
return index_byte(s, byte(r));
case r == utf8.RUNE_ERROR:
for c, i in string(s) {
if c == utf8.RUNE_ERROR {
return i;
}
}
return -1;
case !utf8.valid_rune(r):
return -1;
}
b, w := utf8.encode_rune(r);
return index(s, b[:w]);
}
trim_left_proc_with_state :: proc(s: []byte, p: proc(rawptr, rune) -> bool, state: rawptr) -> []byte {
i := index_proc_with_state(s, p, state, false);
if i == -1 {
return nil;
}
return s[i:];
}
trim_right_proc :: proc(s: []byte, p: proc(rune) -> bool) -> []byte {
i := last_index_proc(s, p, false);
if i >= 0 && s[i] >= utf8.RUNE_SELF {
_, w := utf8.decode_rune(s[i:]);
i += w;
} else {
i += 1;
}
return s[0:i];
}
trim_right_proc_with_state :: proc(s: []byte, p: proc(rawptr, rune) -> bool, state: rawptr) -> []byte {
i := last_index_proc_with_state(s, p, state, false);
if i >= 0 && s[i] >= utf8.RUNE_SELF {
_, w := utf8.decode_rune(s[i:]);
i += w;
} else {
i += 1;
}
return s[0:i];
}
is_in_cutset :: proc(state: rawptr, r: rune) -> bool {
if state == nil {
return false;
}
cutset := (^string)(state)^;
for c in cutset {
if r == c {
return true;
}
}
return false;
}
trim_left :: proc(s: []byte, cutset: []byte) -> []byte {
if s == nil || cutset == nil {
return s;
}
state := cutset;
return trim_left_proc_with_state(s, is_in_cutset, &state);
}
trim_right :: proc(s: []byte, cutset: []byte) -> []byte {
if s == nil || cutset == nil {
return s;
}
state := cutset;
return trim_right_proc_with_state(s, is_in_cutset, &state);
}
trim :: proc(s: []byte, cutset: []byte) -> []byte {
return trim_right(trim_left(s, cutset), cutset);
}
trim_left_space :: proc(s: []byte) -> []byte {
return trim_left_proc(s, is_space);
}
trim_right_space :: proc(s: []byte) -> []byte {
return trim_right_proc(s, is_space);
}
trim_space :: proc(s: []byte) -> []byte {
return trim_right_space(trim_left_space(s));
}
trim_left_null :: proc(s: []byte) -> []byte {
return trim_left_proc(s, is_null);
}
trim_right_null :: proc(s: []byte) -> []byte {
return trim_right_proc(s, is_null);
}
trim_null :: proc(s: []byte) -> []byte {
return trim_right_null(trim_left_null(s));
}
trim_prefix :: proc(s, prefix: []byte) -> []byte {
if has_prefix(s, prefix) {
return s[len(prefix):];
}
return s;
}
trim_suffix :: proc(s, suffix: []byte) -> []byte {
if has_suffix(s, suffix) {
return s[:len(s)-len(suffix)];
}
return s;
}
split_multi :: proc(s: []byte, substrs: [][]byte, skip_empty := false, allocator := context.allocator) -> [][]byte #no_bounds_check {
if s == nil || len(substrs) <= 0 {
return nil;
}
sublen := len(substrs[0]);
for substr in substrs[1:] {
sublen = min(sublen, len(substr));
}
shared := len(s) - sublen;
if shared <= 0 {
return nil;
}
// number, index, last
n, i, l := 0, 0, 0;
// count results
first_pass: for i <= shared {
for substr in substrs {
if string(s[i:i+sublen]) == string(substr) {
if !skip_empty || i - l > 0 {
n += 1;
}
i += sublen;
l = i;
continue first_pass;
}
}
_, skip := utf8.decode_rune(s[i:]);
i += skip;
}
if !skip_empty || len(s) - l > 0 {
n += 1;
}
if n < 1 {
// no results
return nil;
}
buf := make([][]byte, n, allocator);
n, i, l = 0, 0, 0;
// slice results
second_pass: for i <= shared {
for substr in substrs {
if string(s[i:i+sublen]) == string(substr) {
if !skip_empty || i - l > 0 {
buf[n] = s[l:i];
n += 1;
}
i += sublen;
l = i;
continue second_pass;
}
}
_, skip := utf8.decode_rune(s[i:]);
i += skip;
}
if !skip_empty || len(s) - l > 0 {
buf[n] = s[l:];
}
return buf;
}
split_multi_iterator :: proc(s: ^[]byte, substrs: [][]byte, skip_empty := false) -> ([]byte, bool) #no_bounds_check {
if s == nil || s^ == nil || len(substrs) <= 0 {
return nil, false;
}
sublen := len(substrs[0]);
for substr in substrs[1:] {
sublen = min(sublen, len(substr));
}
shared := len(s) - sublen;
if shared <= 0 {
return nil, false;
}
// index, last
i, l := 0, 0;
loop: for i <= shared {
for substr in substrs {
if string(s[i:i+sublen]) == string(substr) {
if !skip_empty || i - l > 0 {
res := s[l:i];
s^ = s[i:];
return res, true;
}
i += sublen;
l = i;
continue loop;
}
}
_, skip := utf8.decode_rune(s[i:]);
i += skip;
}
if !skip_empty || len(s) - l > 0 {
res := s[l:];
s^ = s[len(s):];
return res, true;
}
return nil, false;
}
// scrub scruvs invalid utf-8 characters and replaces them with the replacement string
// Adjacent invalid bytes are only replaced once
scrub :: proc(s: []byte, replacement: []byte, allocator := context.allocator) -> []byte {
str := s;
b: Buffer;
buffer_init_allocator(&b, 0, len(s), allocator);
has_error := false;
cursor := 0;
origin := str;
for len(str) > 0 {
r, w := utf8.decode_rune(str);
if r == utf8.RUNE_ERROR {
if !has_error {
has_error = true;
buffer_write(&b, origin[:cursor]);
}
} else if has_error {
has_error = false;
buffer_write(&b, replacement);
origin = origin[cursor:];
cursor = 0;
}
cursor += w;
str = str[w:];
}
return buffer_to_bytes(&b);
}
reverse :: proc(s: []byte, allocator := context.allocator) -> []byte {
str := s;
n := len(str);
buf := make([]byte, n);
i := n;
for len(str) > 0 {
_, w := utf8.decode_rune(str);
i -= w;
copy(buf[i:], str[:w]);
str = str[w:];
}
return buf;
}
expand_tabs :: proc(s: []byte, tab_size: int, allocator := context.allocator) -> []byte {
if tab_size <= 0 {
panic("tab size must be positive");
}
if s == nil {
return nil;
}
b: Buffer;
buffer_init_allocator(&b, 0, len(s), allocator);
str := s;
column: int;
for len(str) > 0 {
r, w := utf8.decode_rune(str);
if r == '\t' {
expand := tab_size - column%tab_size;
for i := 0; i < expand; i += 1 {
buffer_write_byte(&b, ' ');
}
column += expand;
} else {
if r == '\n' {
column = 0;
} else {
column += w;
}
buffer_write_rune(&b, r);
}
str = str[w:];
}
return buffer_to_bytes(&b);
}
partition :: proc(str, sep: []byte) -> (head, match, tail: []byte) {
i := index(str, sep);
if i == -1 {
head = str;
return;
}
head = str[:i];
match = str[i:i+len(sep)];
tail = str[i+len(sep):];
return;
}
center_justify :: centre_justify; // NOTE(bill): Because Americans exist
// centre_justify returns a byte slice with a pad byte slice at boths sides if the str's rune length is smaller than length
centre_justify :: proc(str: []byte, length: int, pad: []byte, allocator := context.allocator) -> []byte {
n := rune_count(str);
if n >= length || pad == nil {
return clone(str, allocator);
}
remains := length-1;
pad_len := rune_count(pad);
b: Buffer;
buffer_init_allocator(&b, 0, len(str) + (remains/pad_len + 1)*len(pad), allocator);
write_pad_string(&b, pad, pad_len, remains/2);
buffer_write(&b, str);
write_pad_string(&b, pad, pad_len, (remains+1)/2);
return buffer_to_bytes(&b);
}
// left_justify returns a byte slice with a pad byte slice at left side if the str's rune length is smaller than length
left_justify :: proc(str: []byte, length: int, pad: []byte, allocator := context.allocator) -> []byte {
n := rune_count(str);
if n >= length || pad == nil {
return clone(str, allocator);
}
remains := length-1;
pad_len := rune_count(pad);
b: Buffer;
buffer_init_allocator(&b, 0, len(str) + (remains/pad_len + 1)*len(pad), allocator);
buffer_write(&b, str);
write_pad_string(&b, pad, pad_len, remains);
return buffer_to_bytes(&b);
}
// right_justify returns a byte slice with a pad byte slice at right side if the str's rune length is smaller than length
right_justify :: proc(str: []byte, length: int, pad: []byte, allocator := context.allocator) -> []byte {
n := rune_count(str);
if n >= length || pad == nil {
return clone(str, allocator);
}
remains := length-1;
pad_len := rune_count(pad);
b: Buffer;
buffer_init_allocator(&b, 0, len(str) + (remains/pad_len + 1)*len(pad), allocator);
write_pad_string(&b, pad, pad_len, remains);
buffer_write(&b, str);
return buffer_to_bytes(&b);
}
@private
write_pad_string :: proc(b: ^Buffer, pad: []byte, pad_len, remains: int) {
repeats := remains / pad_len;
for i := 0; i < repeats; i += 1 {
buffer_write(b, pad);
}
n := remains % pad_len;
p := pad;
for i := 0; i < n; i += 1 {
r, width := utf8.decode_rune(p);
buffer_write_rune(b, r);
p = p[width:];
}
}
// fields splits the byte slice s around each instance of one or more consecutive white space character, defined by unicode.is_space
// returning a slice of subslices of s or an empty slice if s only contains white space
fields :: proc(s: []byte, allocator := context.allocator) -> [][]byte #no_bounds_check {
n := 0;
was_space := 1;
set_bits := u8(0);
// check to see
for i in 0..<len(s) {
r := s[i];
set_bits |= r;
is_space := int(_ascii_space[r]);
n += was_space & ~is_space;
was_space = is_space;
}
if set_bits >= utf8.RUNE_SELF {
return fields_proc(s, unicode.is_space, allocator);
}
if n == 0 {
return nil;
}
a := make([][]byte, n, allocator);
na := 0;
field_start := 0;
i := 0;
for i < len(s) && _ascii_space[s[i]] != 0 {
i += 1;
}
field_start = i;
for i < len(s) {
if _ascii_space[s[i]] == 0 {
i += 1;
continue;
}
a[na] = s[field_start : i];
na += 1;
i += 1;
for i < len(s) && _ascii_space[s[i]] != 0 {
i += 1;
}
field_start = i;
}
if field_start < len(s) {
a[na] = s[field_start:];
}
return a;
}
// fields_proc splits the byte slice s at each run of unicode code points `ch` satisfying f(ch)
// returns a slice of subslices of s
// If all code points in s satisfy f(ch) or string is empty, an empty slice is returned
//
// fields_proc makes no guarantee about the order in which it calls f(ch)
// it assumes that `f` always returns the same value for a given ch
fields_proc :: proc(s: []byte, f: proc(rune) -> bool, allocator := context.allocator) -> [][]byte #no_bounds_check {
subslices := make([dynamic][]byte, 0, 32, allocator);
start, end := -1, -1;
for r, offset in string(s) {
end = offset;
if f(r) {
if start >= 0 {
append(&subslices, s[start : end]);
// -1 could be used, but just speed it up through bitwise not
// gotta love 2's complement
start = ~start;
}
} else {
if start < 0 {
start = end;
}
}
}
if start >= 0 {
append(&subslices, s[start : end]);
}
return subslices[:];
}