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Diffstat (limited to '')
-rw-r--r-- | dhall/src/semantics/nze/var.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/dhall/src/semantics/nze/var.rs b/dhall/src/semantics/nze/var.rs new file mode 100644 index 0000000..264b81d --- /dev/null +++ b/dhall/src/semantics/nze/var.rs @@ -0,0 +1,36 @@ +use crate::syntax::Label; + +// Exactly like a Label, but equality returns always true. +// This is so that ValueKind equality is exactly alpha-equivalence. +#[derive(Clone, Eq)] +pub struct Binder { + name: Label, +} + +impl Binder { + pub(crate) fn new(name: Label) -> Self { + Binder { name } + } + pub(crate) fn to_label(&self) -> Label { + self.clone().into() + } +} + +/// Equality up to alpha-equivalence +impl std::cmp::PartialEq for Binder { + fn eq(&self, _other: &Self) -> bool { + true + } +} + +impl std::fmt::Debug for Binder { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + write!(f, "Binder({})", &self.name) + } +} + +impl From<Binder> for Label { + fn from(x: Binder) -> Label { + x.name + } +} |