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use tree_morph::prelude::*;
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use uniplate::Uniplate;
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#[derive(Debug, Clone, PartialEq, Eq, Uniplate)]

            

        

            

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#[uniplate()]

            

        

            

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enum Expr {

            

        

            

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    A,

            

        

            

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    B,

            

        

            

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    C,

            

        

            

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    D,

            

        

            

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}

            

        

            

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fn rule_b_to_c(_: &mut Commands<Expr, ()>, expr: &Expr, _: &()) -> Option<Expr> {

            

        

            

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    if let Expr::B = expr {

            

        

            

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        return Some(Expr::C);

            

        

            

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    }

            

        

            

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    None

            

        

            

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}

            

        

            

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#[test]

            

        

            

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fn closure_rules() {

            

        

            

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    let expr = Expr::A;

            

        

            

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    let engine = EngineBuilder::new()

            

        

            

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        .add_rule(

            

        

            

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            // Same as macro expansion

            

        

            

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            (|_, t, _| match t {

            

        

            

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                Expr::A => Some(Expr::B),

            

        

            

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                _ => None,

            

        

            

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            }) as RuleFn<_, _>,

            

        

            

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        )

            

        

            

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        .add_rule_group(rule_fns![

            

        

            

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            |_, t, _| match t {

            

        

            

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                Expr::C => Some(Expr::D),

            

        

            

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                _ => None,

            

        

            

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            },

            

        

            

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            rule_b_to_c,

            

        

            

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        ])

            

        

            

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        .build();

            

        

            

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    let (result, _) = engine.morph(expr, ());

            

        

            

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    assert_eq!(result, Expr::D);

            

        

            

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}