organic/trash/old_combinator.rs
2023-03-25 14:10:22 -04:00

126 lines
4.9 KiB
Rust

use super::parser_context::ContextElement;
use super::parser_context::PreviousElementNode;
use super::token::Token;
use super::Context;
use nom::error::ErrorKind;
use nom::error::ParseError;
use nom::IResult;
use nom::InputLength;
pub fn context_many1<'r, 's, I, O, E, M>(
context: Context<'r, 's>,
mut many_matcher: M,
) -> impl FnMut(I) -> IResult<I, Vec<Token<'s>>, E> + 'r
where
I: Clone + InputLength,
E: ParseError<I>,
M: for<'x> Fn(Context<'x, 's>, I) -> IResult<I, O, E> + 'r,
O: Into<Token<'s>>,
{
move |mut i: I| {
let mut err = None;
// TODO: Can I eliminate the clone? I think this is incrementing the reference count
let mut current_context = context.clone();
// Despite the clone, the Rc should still point to the same value.
assert!(current_context.ptr_eq(context));
loop {
match many_matcher(&current_context, i.clone()) {
Ok((remaining, many_elem)) => {
current_context = current_context.with_additional_node(
ContextElement::PreviousElementNode(PreviousElementNode {
element: many_elem.into(),
}),
);
i = remaining;
}
the_error @ Err(_) => {
err = Some(the_error);
break;
}
}
}
let mut elements: Vec<Token<'s>> = current_context
.into_iter_until(context)
.filter_map(|context_element| match context_element {
ContextElement::PreviousElementNode(elem) => Some(elem.element),
_ => None,
})
.collect();
if elements.is_empty() {
if let Some(err) = err {
err?;
}
}
elements.reverse();
Ok((i, elements))
}
}
pub fn context_many_till<'r, 's, I, O, E, F, M, T>(
context: Context<'r, 's>,
mut many_matcher: M,
mut till_matcher: T,
) -> impl FnMut(I) -> IResult<I, (Vec<Token<'s>>, F), E> + 'r
where
I: Clone + InputLength,
E: ParseError<I>,
M: for<'x> Fn(Context<'x, 's>, I) -> IResult<I, O, E> + 'r,
T: for<'x> Fn(Context<'x, 's>, I) -> IResult<I, F, E> + 'r,
O: Into<Token<'s>>,
{
move |mut i: I| {
// TODO: Can I eliminate the clone? I think this is incrementing the reference count
let mut current_context = context.clone();
// Despite the clone, the Rc should still point to the same value, otherwise we'll get stuck in an endless loop.
assert!(current_context.ptr_eq(context));
loop {
let len = i.input_len();
match till_matcher(&current_context, i.clone()) {
Ok((remaining, finish)) => {
let mut ret = Vec::new();
while !current_context.ptr_eq(context) {
let (context_element, next_context) = current_context.pop_front();
let context_element = context_element.expect("We only pop off context elements created in this function, so they are all Some()");
current_context = next_context;
match context_element {
ContextElement::PreviousElementNode(PreviousElementNode {
element: token,
}) => {
ret.push(token);
}
_ => {}
};
}
ret.reverse();
return Ok((remaining, (ret, finish)));
}
Err(nom::Err::Error(_)) => {
match many_matcher(&current_context, i.clone()) {
Err(nom::Err::Error(err)) => {
return Err(nom::Err::Error(E::append(i, ErrorKind::ManyTill, err)))
}
Err(e) => return Err(e),
Ok((remaining, many_elem)) => {
// infinite loop check: the parser must always consume
if remaining.input_len() == len {
return Err(nom::Err::Error(E::from_error_kind(
remaining,
ErrorKind::ManyTill,
)));
}
current_context = current_context.with_additional_node(
ContextElement::PreviousElementNode(PreviousElementNode {
element: many_elem.into(),
}),
);
i = remaining;
}
}
}
Err(e) => return Err(e),
};
}
}
}