Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/lib.rs')
| -rw-r--r-- | crates/mbe/src/lib.rs | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs index ac107a0d6d..5ef20ff8a9 100644 --- a/crates/mbe/src/lib.rs +++ b/crates/mbe/src/lib.rs @@ -19,6 +19,7 @@ mod benchmark; mod token_map; use ::tt::token_id as tt; +use stdx::impl_from; use std::fmt; @@ -69,7 +70,7 @@ impl fmt::Display for ParseError { } } -#[derive(Debug, PartialEq, Eq, Clone)] +#[derive(Debug, PartialEq, Eq, Clone, Hash)] pub enum ExpandError { BindingError(Box<Box<str>>), LeftoverTokens, @@ -77,8 +78,11 @@ pub enum ExpandError { LimitExceeded, NoMatchingRule, UnexpectedToken, + CountError(CountError), } +impl_from!(CountError for ExpandError); + impl ExpandError { fn binding_error(e: impl Into<Box<str>>) -> ExpandError { ExpandError::BindingError(Box::new(e.into())) @@ -94,6 +98,23 @@ impl fmt::Display for ExpandError { ExpandError::ConversionError => f.write_str("could not convert tokens"), ExpandError::LimitExceeded => f.write_str("Expand exceed limit"), ExpandError::LeftoverTokens => f.write_str("leftover tokens"), + ExpandError::CountError(e) => e.fmt(f), + } + } +} + +// FIXME: Showing these errors could be nicer. +#[derive(Debug, PartialEq, Eq, Clone, Hash)] +pub enum CountError { + OutOfBounds, + Misplaced, +} + +impl fmt::Display for CountError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + CountError::OutOfBounds => f.write_str("${count} out of bounds"), + CountError::Misplaced => f.write_str("${count} misplaced"), } } } @@ -104,9 +125,12 @@ impl fmt::Display for ExpandError { /// and `$()*` have special meaning (see `Var` and `Repeat` data structures) #[derive(Clone, Debug, PartialEq, Eq)] pub struct DeclarativeMacro { - rules: Vec<Rule>, + rules: Box<[Rule]>, /// Highest id of the token we have in TokenMap shift: Shift, + // This is used for correctly determining the behavior of the pat fragment + // FIXME: This should be tracked by hygiene of the fragment identifier! + is_2021: bool, } #[derive(Clone, Debug, PartialEq, Eq)] @@ -190,7 +214,10 @@ pub enum Origin { impl DeclarativeMacro { /// The old, `macro_rules! m {}` flavor. - pub fn parse_macro_rules(tt: &tt::Subtree) -> Result<DeclarativeMacro, ParseError> { + pub fn parse_macro_rules( + tt: &tt::Subtree, + is_2021: bool, + ) -> Result<DeclarativeMacro, ParseError> { // Note: this parsing can be implemented using mbe machinery itself, by // matching against `$($lhs:tt => $rhs:tt);*` pattern, but implementing // manually seems easier. @@ -211,11 +238,11 @@ impl DeclarativeMacro { validate(lhs)?; } - Ok(DeclarativeMacro { rules, shift: Shift::new(tt) }) + Ok(DeclarativeMacro { rules: rules.into_boxed_slice(), shift: Shift::new(tt), is_2021 }) } /// The new, unstable `macro m {}` flavor. - pub fn parse_macro2(tt: &tt::Subtree) -> Result<DeclarativeMacro, ParseError> { + pub fn parse_macro2(tt: &tt::Subtree, is_2021: bool) -> Result<DeclarativeMacro, ParseError> { let mut src = TtIter::new(tt); let mut rules = Vec::new(); @@ -244,14 +271,14 @@ impl DeclarativeMacro { validate(lhs)?; } - Ok(DeclarativeMacro { rules, shift: Shift::new(tt) }) + Ok(DeclarativeMacro { rules: rules.into_boxed_slice(), shift: Shift::new(tt), is_2021 }) } pub fn expand(&self, tt: &tt::Subtree) -> ExpandResult<tt::Subtree> { // apply shift let mut tt = tt.clone(); self.shift.shift_all(&mut tt); - expander::expand_rules(&self.rules, &tt) + expander::expand_rules(&self.rules, &tt, self.is_2021) } pub fn map_id_down(&self, id: tt::TokenId) -> tt::TokenId { @@ -324,12 +351,12 @@ pub struct ValueResult<T, E> { } impl<T, E> ValueResult<T, E> { - pub fn ok(value: T) -> Self { - Self { value, err: None } + pub fn new(value: T, err: E) -> Self { + Self { value, err: Some(err) } } - pub fn with_err(value: T, err: E) -> Self { - Self { value, err: Some(err) } + pub fn ok(value: T) -> Self { + Self { value, err: None } } pub fn only_err(err: E) -> Self |