bitset_core/
fmt.rs

1use core::fmt;
2use super::BitSet;
3
4/// BitSet formatter.
5#[repr(transparent)]
6pub struct BitFmt<T: ?Sized>(T);
7
8fn bitstring<T: ?Sized + BitSet>(this: &T, f: &mut fmt::Formatter) -> fmt::Result {
9	const ALPHABET: [u8; 2] = [b'0', b'1'];
10	let mut buf = [0u8; 9];
11	let mut first = true;
12	buf[0] = b'_';
13	let mut i = 0;
14	while i < this.bit_len() {
15		buf[1] = ALPHABET[this.bit_test(i + 0) as usize];
16		buf[2] = ALPHABET[this.bit_test(i + 1) as usize];
17		buf[3] = ALPHABET[this.bit_test(i + 2) as usize];
18		buf[4] = ALPHABET[this.bit_test(i + 3) as usize];
19		buf[5] = ALPHABET[this.bit_test(i + 4) as usize];
20		buf[6] = ALPHABET[this.bit_test(i + 5) as usize];
21		buf[7] = ALPHABET[this.bit_test(i + 6) as usize];
22		buf[8] = ALPHABET[this.bit_test(i + 7) as usize];
23		let s = unsafe { &*((&buf[first as usize..]) as *const _ as *const str) };
24		f.write_str(s)?;
25		i += 8;
26		first = false;
27	}
28	Ok(())
29}
30
31const UPPERHEX_ALPHABET: [u8; 16] = *b"0123456789ABCDEF";
32const LOWERHEX_ALPHABET: [u8; 16] = *b"0123456789abcdef";
33
34fn hexstring<T: ?Sized + BitSet>(this: &T, f: &mut fmt::Formatter, alphabet: &[u8; 16]) -> fmt::Result {
35	let mut buf = [0u8; 2];
36	let mut i = 0;
37	while i < this.bit_len() {
38		let byte =
39			(this.bit_test(i + 0) as u8) << 7 |
40			(this.bit_test(i + 1) as u8) << 6 |
41			(this.bit_test(i + 2) as u8) << 5 |
42			(this.bit_test(i + 3) as u8) << 4 |
43			(this.bit_test(i + 4) as u8) << 3 |
44			(this.bit_test(i + 5) as u8) << 2 |
45			(this.bit_test(i + 6) as u8) << 1 |
46			(this.bit_test(i + 7) as u8) << 0;
47		buf[0] = alphabet[(byte >> 4) as usize];
48		buf[1] = alphabet[(byte & 0xf) as usize];
49		let s = unsafe { &*((&buf[..]) as *const _ as *const str) };
50		f.write_str(s)?;
51		i += 8;
52	}
53	Ok(())
54}
55
56impl<T: ?Sized + BitSet> fmt::Display for BitFmt<T> {
57	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
58		bitstring(&self.0, f)
59	}
60}
61impl<T: ?Sized + BitSet> fmt::Debug for BitFmt<T> {
62	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
63		f.write_str("\"")?;
64		hexstring(&self.0, f, &UPPERHEX_ALPHABET)?;
65		f.write_str("\"")?;
66		Ok(())
67	}
68}
69
70impl<T: ?Sized + BitSet> fmt::UpperHex for BitFmt<T> {
71	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
72		hexstring(&self.0, f, &UPPERHEX_ALPHABET)
73	}
74}
75impl<T: ?Sized + BitSet> fmt::LowerHex for BitFmt<T> {
76	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
77		hexstring(&self.0, f, &LOWERHEX_ALPHABET)
78	}
79}
bitset_core/fmt.rs

bitset_core/
fmt.rs
