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use crate::{
fun::{Book, Term},
maybe_grow,
};
impl Book {
/// Inline copies of the declared bind in the `use` expression.
///
/// Example:
/// ```bend
/// use id = λx x
/// (id id id)
///
/// // Transforms to:
/// (λx x λx x λx x)
/// ```
pub fn desugar_use(&mut self) {
for def in self.defs.values_mut() {
for rule in def.rules.iter_mut() {
rule.body.desugar_use();
}
}
}
}
impl Term {
pub fn desugar_use(&mut self) {
maybe_grow(|| {
for children in self.children_mut() {
children.desugar_use();
}
});
if let Term::Use { nam: Some(nam), val, nxt } = self {
nxt.subst(nam, val);
*self = std::mem::take(nxt);
}
}
}