From 77af0bbc171618f48531cc6b1d77e18089928885 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Tue, 13 Aug 2019 20:54:15 +0200 Subject: Stop tracking the absence of Embed values at the type level --- dhall_syntax/src/core/context.rs | 2 +- dhall_syntax/src/core/expr.rs | 16 ++-------------- dhall_syntax/src/core/visitor.rs | 15 +-------------- dhall_syntax/src/printer.rs | 6 ------ 4 files changed, 4 insertions(+), 35 deletions(-) (limited to 'dhall_syntax/src') diff --git a/dhall_syntax/src/core/context.rs b/dhall_syntax/src/core/context.rs index eeec121..6844baa 100644 --- a/dhall_syntax/src/core/context.rs +++ b/dhall_syntax/src/core/context.rs @@ -4,7 +4,7 @@ use std::hash::Hash; /// A `(Context a)` associates `Text` labels with values of type `a` /// -/// The `Context` is used for type-checking when `(a = Expr X)` +/// The `Context` is used for type-checking when `(a = Expr)` /// /// * You create a `Context` using `empty` and `insert` /// * You transform a `Context` using `fmap` diff --git a/dhall_syntax/src/core/expr.rs b/dhall_syntax/src/core/expr.rs index 0cbece3..e08d816 100644 --- a/dhall_syntax/src/core/expr.rs +++ b/dhall_syntax/src/core/expr.rs @@ -10,9 +10,9 @@ pub type Double = NaiveDouble; /// An empty type #[derive(Debug, Copy, Clone, PartialEq, Eq)] -pub enum X {} +pub enum Void {} -pub fn trivial_result(x: Result) -> T { +pub fn trivial_result(x: Result) -> T { match x { Ok(x) => x, Err(e) => match e {}, @@ -351,12 +351,6 @@ impl Expr { } } -impl Expr { - pub fn absurd(&self) -> Expr { - self.visit(&mut visitor::AbsurdVisitor) - } -} - impl SubExpr { pub fn as_ref(&self) -> &Expr { &self.0.as_ref().0 @@ -416,12 +410,6 @@ impl SubExpr { } } -impl SubExpr { - pub fn absurd(&self) -> SubExpr { - SubExpr::from_expr_no_span(self.as_ref().absurd()) - } -} - impl Clone for SubExpr { fn clone(&self) -> Self { SubExpr(Rc::clone(&self.0)) diff --git a/dhall_syntax/src/core/visitor.rs b/dhall_syntax/src/core/visitor.rs index 50ec68a..e39e95b 100644 --- a/dhall_syntax/src/core/visitor.rs +++ b/dhall_syntax/src/core/visitor.rs @@ -243,7 +243,7 @@ impl<'a, T, SE1, SE2, E1, E2> ExprFFallibleVisitor<'a, SE1, SE2, E1, E2> where T: ExprFInFallibleVisitor<'a, SE1, SE2, E1, E2>, { - type Error = X; + type Error = Void; fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result { Ok(self.0.visit_subexpr(subexpr)) @@ -379,16 +379,3 @@ where (self.0)(embed) } } - -pub struct AbsurdVisitor; - -impl<'a, 'b, E> ExprFInFallibleVisitor<'a, SubExpr, SubExpr, X, E> - for &'b mut AbsurdVisitor -{ - fn visit_subexpr(&mut self, subexpr: &'a SubExpr) -> SubExpr { - SubExpr::from_expr_no_span(subexpr.as_ref().visit(&mut **self)) - } - fn visit_embed(self, embed: &'a X) -> E { - match *embed {} - } -} diff --git a/dhall_syntax/src/printer.rs b/dhall_syntax/src/printer.rs index 95eafe5..25d4ca8 100644 --- a/dhall_syntax/src/printer.rs +++ b/dhall_syntax/src/printer.rs @@ -491,9 +491,3 @@ impl Display for V