surrounded by

This commit is contained in:
Greg Shuflin 2024-01-29 10:09:44 -08:00
parent d8a68bcbf3
commit cdbbb8214f
2 changed files with 36 additions and 1 deletions

View File

@ -1,4 +1,4 @@
use crate::{map, seq2}; use crate::{map, seq2, surrounded_by};
pub type ParseResult<I, O, E> = Result<(O, I), (E, I)>; pub type ParseResult<I, O, E> = Result<(O, I), (E, I)>;
@ -24,6 +24,7 @@ pub trait ParserExtension<I, O, E>: Parser<I, O, E> {
fn then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, (O, O2), E>; fn then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, (O, O2), E>;
fn then_ignore<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O, E>; fn then_ignore<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O, E>;
fn ignore_then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O2, E>; fn ignore_then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O2, E>;
fn surrounded_by<O2>(self, surrounding: impl Parser<I, O2, E>) -> impl Parser<I, O, E>;
} }
impl<T, I, O, E> ParserExtension<I, O, E> for T impl<T, I, O, E> ParserExtension<I, O, E> for T
@ -51,4 +52,7 @@ where
fn ignore_then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O2, E> { fn ignore_then<O2, P: Parser<I, O2, E>>(self, next: P) -> impl Parser<I, O2, E> {
seq2(self, next).map(|(_, next)| next) seq2(self, next).map(|(_, next)| next)
} }
fn surrounded_by<O2>(self, surrounding: impl Parser<I, O2, E>) -> impl Parser<I, O, E> {
surrounded_by(self, surrounding)
}
} }

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@ -7,6 +7,18 @@ where
move |input| -> ParseResult<I, O, E> { sequence.parse(input) } move |input| -> ParseResult<I, O, E> { sequence.parse(input) }
} }
pub fn surrounded_by<I, O1, O2, E>(
main: impl Parser<I, O1, E>,
surrounding: impl Parser<I, O2, E>,
) -> impl Parser<I, O1, E> {
move |input| {
let (_result1, rest1) = surrounding.parse(input)?;
let (result2, rest2) = main.parse(rest1)?;
let (_result3, rest3) = surrounding.parse(rest2)?;
Ok((result2, rest3))
}
}
pub fn seq2<I, O1, O2, E>( pub fn seq2<I, O1, O2, E>(
first: impl Parser<I, O1, E>, first: impl Parser<I, O1, E>,
second: impl Parser<I, O2, E>, second: impl Parser<I, O2, E>,
@ -32,3 +44,22 @@ where
}) })
} }
} }
impl<P1, P2, P3, I, O1, O2, O3, E> Sequence<I, (O1, O2, O3), E> for (P1, P2, P3)
where
P1: Parser<I, O1, E>,
P2: Parser<I, O2, E>,
P3: Parser<I, O3, E>,
{
fn parse(&self, input: I) -> ParseResult<I, (O1, O2, O3), E> {
let p1 = &self.0;
let p2 = &self.1;
let p3 = &self.2;
let (result1, rest1) = p1.parse(input)?;
let (result2, rest2) = p2.parse(rest1)?;
let (result3, rest3) = p3.parse(rest2)?;
Ok(((result1, result2, result3), rest3))
}
}