futilehdl/src/parser/literals.rs

55 lines
1.3 KiB
Rust

use nom::{
branch::alt,
bytes::complete::tag,
character::complete::{alpha1, alphanumeric1, char, multispace0, one_of},
combinator::{map, recognize},
error::ParseError,
multi::{many0, many1},
sequence::{delimited, pair, preceded, terminated},
};
use crate::parser::{IResult, Span};
pub fn hexadecimal(input: Span) -> IResult<Span, u64> {
map(
preceded(
char('h'),
recognize(many1(terminated(
one_of("0123456789abcdefABCDEF"),
many0(char('_')),
))),
),
|out: Span| {
u64::from_str_radix(&str::replace(out.fragment(), "_", ""), 16)
.expect("error parsing literal")
},
)(input)
}
pub fn ws0<'a, F: 'a, O, E: ParseError<Span<'a>>>(
inner: F,
) -> impl FnMut(Span<'a>) -> IResult<Span<'a>, O, E>
where
F: FnMut(Span<'a>) -> IResult<Span<'a>, O, E>,
{
delimited(multispace0, inner, multispace0)
}
pub fn identifier(input: Span) -> IResult<Span, Span> {
recognize(pair(
alt((alpha1, tag("_"))),
many0(alt((alphanumeric1, tag("_")))),
))(input)
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_hex() {
assert_eq!(hexadecimal("hfF".into()).unwrap().1, 0xff);
assert_eq!(hexadecimal("hF".into()).unwrap().1, 0xf);
}
}