45 lines
1.4 KiB
Rust
45 lines
1.4 KiB
Rust
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// © 2023 John Breaux
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use super::*;
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/// Parses tokens from [stream](TokenStream) into Self node
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pub trait Parsable {
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/// Parses tokens from [TokenStream](TokenStream) into Self nodes
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fn parse<'text, T>(p: &Parser, stream: &mut T) -> Result<Self, Error>
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where
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Self: Sized,
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T: TokenStream<'text>;
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/// Attempts to parse tokens from [stream](TokenStream) into Self nodes.
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///
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/// Masks failed expectations.
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fn try_parse<'text, T>(p: &Parser, stream: &mut T) -> Result<Option<Self>, Error>
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where
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Self: Sized,
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T: TokenStream<'text>,
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{
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match Self::parse(p, stream).map_err(|e| e.bare()) {
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Ok(tt) => Ok(Some(tt)),
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Err(Error::UnexpectedToken { .. }) | Err(Error::AllExpectationsFailed { .. }) => Ok(None),
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Err(e) => Err(e),
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}
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}
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fn parse_and<'text, T, R>(p: &Parser, stream: &mut T, f: fn(p: &Parser, &mut T) -> R) -> Result<(Self, R), Error>
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where
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Self: Sized,
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T: TokenStream<'text>,
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{
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Ok((Self::parse(p, stream)?, f(p, stream)))
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}
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/// Attempts to parse tokens from [stream](TokenStream) into Self nodes.
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///
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/// Returns [`Self::default()`](Default::default()) on error
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fn parse_or_default<'text, T>(p: &Parser, stream: &mut T) -> Self
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where
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Self: Sized + Default,
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T: TokenStream<'text>,
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{
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Self::parse(p, stream).unwrap_or_default()
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}
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}
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