22 lines
540 B
Rust
22 lines
540 B
Rust
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use crate::Parser;
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pub fn choice<'a, I, O, E>(parsers: &'a [&'a dyn Parser<I, O, E>]) -> impl Parser<I, O, E> + 'a
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where
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I: Clone,
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{
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move |input: I| {
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//TODO need a more principled way to return an error when no choices work
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let mut err = None;
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for parser in parsers.iter() {
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match parser.parse(input.clone()) {
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Ok(res) => return Ok(res),
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Err(e) => {
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err = Some(e);
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}
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}
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}
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Err(err.unwrap())
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}
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}
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