jcgruenhage/aoc-rs-2021
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

make parse_number fallible

Browse source
This commit is contained in:
Jan Christian Grünhage 2021-12-18 17:28:06 +01:00
parent 81b7e84097
commit 71be88574c
1 changed files with 17 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

32
src/parsing.rs
View file

@ -22,21 +22,23 @@ pub fn parse_number_with_radix<T: Num>(
base: u32,
limit: Option<usize>,
) -> Option<T> {
tokens.skip_tokens_while(|t| *t == ' ');
let mut remaining = limit.map(|x| x as isize).unwrap_or(isize::MAX);
let mut prefix = String::new();
if tokens.token('-') {
prefix.push('-');
}
let digits: String = tokens
.tokens_while(|c| {
remaining -= 1;
c.is_digit(base) && remaining >= 0
})
.collect();
(!digits.is_empty())
.then(|| T::from_str_radix(&format!("{}{}", prefix, digits), base).ok())
.flatten()
tokens.optional(|t| {
t.skip_tokens_while(|t| *t == ' ');
let mut remaining = limit.map(|x| x as isize).unwrap_or(isize::MAX);
let mut prefix = String::new();
if t.token('-') {
prefix.push('-');
}
let digits: String = t
.tokens_while(|c| {
remaining -= 1;
c.is_digit(base) && remaining >= 0
})
.collect();
(!digits.is_empty())
.then(|| T::from_str_radix(&format!("{}{}", prefix, digits), base).ok())
.flatten()
})
}
pub fn parse_n<R, T, I, P, S, const N: usize>(