lexical_util/
ascii.rs

1//! Utilities for working with ASCII characters.
2
3/// Determine if a character is a valid ASCII character for float grammar.
4#[inline(always)]
5pub const fn is_valid_ascii(c: u8) -> bool {
6    // Below 0x20 is mostly control characters, with no representation.
7    // 0x7F is a control character, DEL, so don't include it.
8    // We also want the few visual characters below 0x20:
9    //  0x09 - Horizontal Tab
10    //  0x0A - Newline
11    //  0x0B - Vertical Tab (Deprecated)
12    //  0x0C - Form Feed (Deprecated)
13    //  0x0D - Carriage Return
14    (c >= 0x09 && c <= 0x0d) || (c >= 0x20 && c < 0x7F)
15}
16
17/// Determine if a slice is all valid ASCII characters for float grammar.
18#[inline(always)]
19pub const fn is_valid_ascii_slice(slc: &[u8]) -> bool {
20    let mut index = 0;
21    while index < slc.len() {
22        if !is_valid_ascii(slc[index]) {
23            return false;
24        }
25        index += 1;
26    }
27    true
28}
29
30/// Determine if a character is a valid ASCII letter.
31#[inline(always)]
32pub const fn is_valid_letter(c: u8) -> bool {
33    (c >= 0x41 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a)
34}
35
36/// Determine if a slice is all valid ASCII letters.
37#[inline(always)]
38pub const fn is_valid_letter_slice(slc: &[u8]) -> bool {
39    let mut index = 0;
40    while index < slc.len() {
41        if !is_valid_letter(slc[index]) {
42            return false;
43        }
44        index += 1;
45    }
46    true
47}
lexical_util/ascii.rs

lexical_util/
ascii.rs
