well thats it, i need either an array of booleans(u1) that represent bits of a value that i provided.
#how do i get bits array from a value?
hearty charm
void sparrow
There isn't language-level support for bit-packed arrays of this form, but you can fairly easily access individual bits with bitwise operations. Do you know what bit endian you're working in?
hearty charm
There isn't language-level support for bit-packed arrays of this form, but you c...
i'm sorry, is bit endian sort of like architecture of the processor? 32-64. I don't know a lot about this
void sparrow
No, bit endian is a detail of what you're doing. Basically, when you're trying to access bits in order, you need to decide whether you want to read the LSB of a byte first, or the MSB of a byte first
hearty charm
i really just need to see fourth bit for example, or sixth, something like that
So maybe not least significant of most significant bit, maybe something inbetween
void sparrow
i really just need to see fourth bit for example, or sixth, something like that
But when you say "first bit", do you mean least significant bit in the first byte (i.e. representing value 1), or most significant bit in the first byte (i.e. representing value 128)
hearty charm
first bit is LSB
void sparrow
Okay, cool - that's bit-little-endian
hearty charm
oh great
void sparrow
gimme a few moments and i'll write you some simple bit getter/setter functions
hearty charm
oh thanks a lot. Much appreciated
void sparrow
pub fn getBit(buf: []const u8, idx: usize) bool {
return (buf[idx / 8] >> @intCast(idx % 8)) & 1 == 1;
}
pub fn setBit(buf: []const u8, idx: usize, val: bool) void {
if (val) {
buf[idx / 8] |= @as(u8, 1) << @intCast(idx % 8);
} else {
buf[idx / 8] &= ~(@as(u8, 1) << @intCast(idx % 8));
}
}
Untested but I think this is right