fix indentation and simplify hex.decode_sequence

This commit is contained in:
Laytan Laats
2023-05-15 18:40:36 +02:00
parent a381846034
commit 6e4fab19a2

View File

@@ -4,12 +4,12 @@ import "core:strings"
encode :: proc(src: []byte, allocator := context.allocator) -> []byte #no_bounds_check {
dst := make([]byte, len(src) * 2, allocator)
for i := 0; i < len(src); i += 1 {
for i := 0; i < len(src); i += 1 {
v := src[i]
dst[i] = HEXTABLE[v>>4]
dst[i+1] = HEXTABLE[v&0x0f]
i += 2
}
dst[i] = HEXTABLE[v>>4]
dst[i+1] = HEXTABLE[v&0x0f]
i += 2
}
return dst
}
@@ -36,39 +36,38 @@ decode :: proc(src: []byte, allocator := context.allocator) -> (dst: []byte, ok:
}
// Decodes the given sequence into one byte.
// Should be called with one rune worth of the source, eg: 0x23 -> '#'.
decode_sequence :: proc(str: string) -> (byte, bool) {
no_prefix_str := strings.trim_prefix(str, "0x")
val: byte
for i := 0; i < len(no_prefix_str); i += 1 {
index := (len(no_prefix_str) - 1) - i // reverse the loop.
hd, ok := hex_digit(no_prefix_str[i])
if !ok {
return 0, false
}
val += u8(hd) << uint(4 * index)
// Should be called with one byte worth of the source, eg: 0x23 -> '#'.
decode_sequence :: proc(str: string) -> (res: byte, ok: bool) {
str := str
if strings.has_prefix(str, "0x") || strings.has_prefix(str, "0X") {
str = str[2:]
}
return val, true
if len(str) != 2 {
return 0, false
}
upper := hex_digit(str[0]) or_return
lower := hex_digit(str[1]) or_return
return upper << 4 | lower, true
}
@(private)
HEXTABLE := [16]byte {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f',
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f',
}
@(private)
hex_digit :: proc(char: byte) -> (u8, bool) {
switch char {
case '0' ..= '9': return char - '0', true
case 'a' ..= 'f': return char - 'a' + 10, true
case 'A' ..= 'F': return char - 'A' + 10, true
case: return 0, false
}
switch char {
case '0' ..= '9': return char - '0', true
case 'a' ..= 'f': return char - 'a' + 10, true
case 'A' ..= 'F': return char - 'A' + 10, true
case: return 0, false
}
}