FastWaveBackend/src/vcd/utilities.rs

75 lines
1.9 KiB
Rust

#[derive(Debug)]
pub(super) enum BinaryParserErrTypes {
XValue,
ZValue,
UValue,
OtherValue(char),
TooLong,
}
// We build a quick and not so dirty bit string parser.
fn base2_str_to_byte(word: &[u8]) -> Result<u8, BinaryParserErrTypes> {
let mut val = 0u8;
// shouldn't have more than 8 chars in str
let len = word.len();
if len > 8 {
return Err(BinaryParserErrTypes::TooLong);
}
let bit_lut = [
0b0000_0001u8,
0b0000_0010u8,
0b0000_0100u8,
0b0000_1000u8,
0b0001_0000u8,
0b0010_0000u8,
0b0100_0000u8,
0b1000_0000u8,
];
for (idx, chr) in word.iter().rev().enumerate() {
match chr {
b'1' => val = bit_lut[idx] | val,
b'0' => {}
b'x' | b'X' => return Err(BinaryParserErrTypes::XValue),
b'z' | b'Z' => return Err(BinaryParserErrTypes::ZValue),
b'u' | b'U' => return Err(BinaryParserErrTypes::UValue),
_ => return Err(BinaryParserErrTypes::OtherValue(*chr as char)),
}
}
Ok(val)
}
pub(super) fn binary_str_to_vec_u8(binary_str: &str) -> Result<Vec<u8>, BinaryParserErrTypes> {
let mut vec_u8: Vec<u8> = Vec::new();
let binary_str_as_bytes = binary_str.as_bytes();
let mut tail_idx = binary_str_as_bytes.len();
// clamp head if provided binary str is less than 8 long
let mut head_idx = if tail_idx >= 8 {
binary_str_as_bytes.len() - 8
} else {
0
};
while tail_idx > 0 {
let curr_b_val = &binary_str_as_bytes[head_idx..tail_idx];
let val_u8 = base2_str_to_byte(curr_b_val)?;
vec_u8.push(val_u8);
if head_idx < 8 {
head_idx = 0
} else {
head_idx = head_idx - 8;
}
if tail_idx < 8 {
tail_idx = 0
} else {
tail_idx = tail_idx - 8;
}
}
Ok(vec_u8)
}