2019-01-31 04:59:25 -06:00
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use rustc_hash::FxHashMap;
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use smol_str::SmolStr;
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2019-01-31 04:49:57 -06:00
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use crate::{mbe, tt};
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2019-01-31 04:59:25 -06:00
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pub fn exapnd(rules: &mbe::MacroRules, input: &tt::Subtree) -> Option<tt::Subtree> {
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rules.rules.iter().find_map(|it| expand_rule(it, input))
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}
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fn expand_rule(rule: &mbe::Rule, input: &tt::Subtree) -> Option<tt::Subtree> {
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let bidings = match_lhs(&rule.lhs, input)?;
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expand_rhs(&rule.rhs, &bindings)
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}
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#[derive(Debug, Default)]
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struct Bindings {
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inner: FxHashMap<SmolStr, tt::TokenTree>,
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}
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fn match_lhs(pattern: &mbe::TokenTree, input: &tt::Subtree) -> Option<Bindings> {
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Some(Bindings::default())
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}
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fn expand_rhs(template: &mbe::TokenTree, bindings: &Bindings) -> Option<tt::Subtree> {
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None
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2019-01-31 04:49:57 -06:00
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}
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