diff options
Diffstat (limited to 'dhall_core/src')
| -rw-r--r-- | dhall_core/src/core.rs | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/dhall_core/src/core.rs b/dhall_core/src/core.rs index 72b42f8..a20f6d1 100644 --- a/dhall_core/src/core.rs +++ b/dhall_core/src/core.rs @@ -433,6 +433,17 @@ impl<N, E> SubExpr<N, E> { { rc(self.as_ref().visit(&mut visitor::UnNoteVisitor)) } + + pub fn subst_shift(&self, var: &V<Label>, val: &Self) -> Self { + match self.as_ref() { + ExprF::Var(v) if v == var => val.clone(), + ExprF::Var(v) => rc(ExprF::Var(v.shift(-1, var))), + _ => self.map_subexprs_with_special_handling_of_binders( + |e| e.subst_shift(var, val), + |x: &Label, e| e.subst_shift(&var.shift0(1, x), val), + ), + } + } } impl<N: Clone> SubExpr<N, X> { @@ -499,15 +510,11 @@ pub fn shift<N, E>( var: &V<Label>, in_expr: &SubExpr<N, E>, ) -> SubExpr<N, E> { - use crate::ExprF::*; match in_expr.as_ref() { - Var(v) => rc(Var(v.shift(delta, var))), + ExprF::Var(v) => rc(ExprF::Var(v.shift(delta, var))), _ => in_expr.map_subexprs_with_special_handling_of_binders( |e| shift(delta, var, e), - |l: &Label, e| { - let newvar = var.shift0(1, l); - shift(delta, &newvar, e) - }, + |x: &Label, e| shift(delta, &var.shift0(1, x), e), ), } } @@ -540,8 +547,8 @@ fn shift0_multiple_inner<N, E>( } _ => in_expr.map_subexprs_with_special_handling_of_binders( |e| shift0_multiple_inner(ctx, deltas, e), - |l: &Label, e| { - shift0_multiple_inner(&ctx.insert(l.clone(), ()), deltas, e) + |x: &Label, e| { + shift0_multiple_inner(&ctx.insert(x.clone(), ()), deltas, e) }, ), } |