From 509743469035582d916e6a2f331fd5018c81447e Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Fri, 16 Aug 2019 11:11:28 +0200 Subject: Use `!` type instead of custom empty type --- dhall_syntax/src/core/expr.rs | 14 ++------------ dhall_syntax/src/core/visitor.rs | 2 +- dhall_syntax/src/lib.rs | 1 + dhall_syntax/src/parser.rs | 4 ++-- 4 files changed, 6 insertions(+), 15 deletions(-) (limited to 'dhall_syntax') diff --git a/dhall_syntax/src/core/expr.rs b/dhall_syntax/src/core/expr.rs index 30ac4eb..efbcee2 100644 --- a/dhall_syntax/src/core/expr.rs +++ b/dhall_syntax/src/core/expr.rs @@ -8,20 +8,10 @@ pub type Integer = isize; pub type Natural = usize; pub type Double = NaiveDouble; -/// An empty type -#[derive(Debug, Copy, Clone, PartialEq, Eq)] -pub enum Void {} - -impl std::fmt::Display for Void { - fn fmt(&self, _f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> { - match *self {} - } -} - -pub fn trivial_result(x: Result) -> T { +pub fn trivial_result(x: Result) -> T { match x { Ok(x) => x, - Err(e) => match e {}, + Err(e) => e, } } diff --git a/dhall_syntax/src/core/visitor.rs b/dhall_syntax/src/core/visitor.rs index 7b4ed4b..5a5fcc9 100644 --- a/dhall_syntax/src/core/visitor.rs +++ b/dhall_syntax/src/core/visitor.rs @@ -176,7 +176,7 @@ impl<'a, T, SE1, SE2, E1, E2> ExprFFallibleVisitor<'a, SE1, SE2, E1, E2> where T: ExprFInFallibleVisitor<'a, SE1, SE2, E1, E2>, { - type Error = Void; + type Error = !; fn visit_subexpr(&mut self, subexpr: &'a SE1) -> Result { Ok(self.0.visit_subexpr(subexpr)) diff --git a/dhall_syntax/src/lib.rs b/dhall_syntax/src/lib.rs index 8406595..4566e64 100644 --- a/dhall_syntax/src/lib.rs +++ b/dhall_syntax/src/lib.rs @@ -1,6 +1,7 @@ #![feature(trace_macros)] #![feature(slice_patterns)] #![feature(try_blocks)] +#![feature(never_type)] #![allow( clippy::many_single_char_names, clippy::should_implement_trait, diff --git a/dhall_syntax/src/parser.rs b/dhall_syntax/src/parser.rs index d467970..bcaa00e 100644 --- a/dhall_syntax/src/parser.rs +++ b/dhall_syntax/src/parser.rs @@ -18,8 +18,8 @@ use crate::*; // their own crate because they are quite general and useful. For now they // are here and hopefully you can figure out how they work. -pub(crate) type ParsedExpr = Expr; -pub(crate) type ParsedSubExpr = SubExpr; +pub(crate) type ParsedExpr = Expr; +pub(crate) type ParsedSubExpr = SubExpr; type ParsedText = InterpolatedText; type ParsedTextContents = InterpolatedTextContents; -- cgit v1.2.3