forked from Orchid/orchid
43 lines
1.2 KiB
Rust
43 lines
1.2 KiB
Rust
use std::fmt::Debug;
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use std::hash::Hash;
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use std::rc::Rc;
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use crate::external::assertion_error::AssertionError;
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use crate::representations::PathSet;
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use crate::{atomic_impl, atomic_redirect, externfn_impl};
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use crate::representations::interpreted::Clause;
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use super::Boolean;
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/// IfThenElse function
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///
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/// Next state: [IfThenElse0]
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#[derive(Clone)]
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pub struct IfThenElse1;
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externfn_impl!(IfThenElse1, |_: &Self, c: Clause| {Ok(IfThenElse0{c})});
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/// Partially applied IfThenElse function
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///
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/// Prev state: [IfThenElse1]; Next state: [IfThenElse0]
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#[derive(Debug, Clone, PartialEq, Hash)]
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pub struct IfThenElse0{ c: Clause }
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atomic_redirect!(IfThenElse0, c);
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atomic_impl!(IfThenElse0, |this: &Self| {
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let Boolean(b) = (&this.c).try_into()
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.map_err(|_| AssertionError::ext(this.c.clone(), "a boolean"))?;
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Ok(if b { Clause::Lambda {
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args: Some(PathSet { steps: Rc::new(vec![]), next: None }),
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body: Rc::new(Clause::Lambda {
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args: None,
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body: Rc::new(Clause::LambdaArg)
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})
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}} else { Clause::Lambda {
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args: None,
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body: Rc::new(Clause::Lambda {
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args: Some(PathSet { steps: Rc::new(vec![]), next: None }),
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body: Rc::new(Clause::LambdaArg)
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})
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}})
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}); |