32 lines
865 B
Plaintext
32 lines
865 B
Plaintext
use std::str::FromStr;
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use std::rc::Rc;
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use crate::ast::Form;
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grammar;
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pub Term: Form = {
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NUM => Form::Int(i32::from_str(<>).unwrap()),
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SYM => Form::Symbol(<>.to_owned()),
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"(" <ListInside?> ")" => <>.unwrap_or(Form::Nil),
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"'" <Term> => Form::Pair(Rc::new(Form::Symbol("quote".to_owned())), Rc::new(Form::Pair(Rc::new(<>), Rc::new(Form::Nil)))),
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"!" <h: Term> <t: Term> => {
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h.append(Rc::new(t)).unwrap()
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},
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};
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ListInside: Form = {
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<Term> => Form::Pair(Rc::new(<>), Rc::new(Form::Nil)),
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<h: Term> <t: ListInside> => Form::Pair(Rc::new(h), Rc::new(t)),
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<a: Term> "." <d: Term> => Form::Pair(Rc::new(a), Rc::new(d)),
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}
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match {
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"(",
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")",
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".",
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"'",
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"!",
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r"[0-9]+" => NUM,
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r"[a-zA-Z+*/_=?%&|^<>-][\w+*/=_?%&|^<>-]*" => SYM,
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r"(;[^\n]*\n)|\s+" => { }
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}
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