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tamer: parse::lower:::Lower::lower: Implement in terms of lower_with_context 

This is just a special case of lowering with a context, and maintaining two
separate implementations has resulted in divergence.  I don't recall why I
didn't do this previously, though it's possible that the lowering pipeline
was in a state that made it more difficult to do (e.g. with error
handling).

DEV-13708
main
Mike Gerwitz 2023-02-22 08:44:30 -05:00
parent 6db70385d0
commit fe925db47d
1 changed files with 11 additions and 11 deletions
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22
tamer/src/parse/lower.rs
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@ -121,17 +121,11 @@ where
) -> Result<U, E>
where
Self: Iterator<Item = WidenedParsedResult<S, EW>> + Sized,
E: Diagnostic + From<FinalizeError>,
<LS as ParseState>::Context: Default,
{
let lower = LS::parse(iter::empty());
let mut iter = LowerIter {
lower,
toks: self,
_phantom: PhantomData::default(),
};
f(&mut iter)
// TODO: Finalize!
self.lower_with_context(<LS as ParseState>::Context::default(), f)
.map(|(val, _ctx)| val)
}
/// Perform a lowering operation between two parsers where the context
@ -144,14 +138,14 @@ where
#[inline]
fn lower_with_context<U, E>(
&mut self,
ctx: LS::Context,
ctx: impl Into<LS::Context>,
f: impl FnOnce(&mut LowerIter<S, Self, LS, EW>) -> Result<U, E>,
) -> Result<(U, LS::Context), E>
where
Self: Iterator<Item = WidenedParsedResult<S, EW>> + Sized,
E: Diagnostic + From<FinalizeError>,
{
let lower = LS::parse_with_context(iter::empty(), ctx);
let lower = LS::parse_with_context(iter::empty(), ctx.into());
let mut iter = LowerIter {
lower,
toks: self,
@ -407,6 +401,12 @@ mod test {
let given = 27; // some value
let toks = vec![StubToken::YieldWithLookahead(given)];
impl From<FinalizeError> for StubError {
fn from(_: FinalizeError) -> Self {
unreachable!("not expected to be used by this test")
}
}
Lower::<StubEchoParseState, StubParseState, _>::lower::<_, StubError>(
&mut StubEchoParseState::parse(toks.into_iter()),
|sut| {