From 04c6cd248aff1cbce68ae2fb997705e921d21809 Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Thu, 4 Apr 2019 18:12:19 +0200
Subject: Tweak matching on Some/None

---
 dhall_core/src/parser.rs | 30 +++++++++---------------------
 1 file changed, 9 insertions(+), 21 deletions(-)

(limited to 'dhall_core/src/parser.rs')

diff --git a/dhall_core/src/parser.rs b/dhall_core/src/parser.rs
index a0e4397..68796c4 100644
--- a/dhall_core/src/parser.rs
+++ b/dhall_core/src/parser.rs
@@ -700,28 +700,16 @@ make_parser! {
 
     rule!(application_expression<ParsedExpr> as expression; children!(
         [expression(e)] => e,
-        [expression(first), expression(second)] => {
-            match first {
-                Expr::Builtin(Builtin::OptionalNone) =>
-                    Expr::EmptyOptionalLit(rc(second)),
-                Expr::Builtin(Builtin::OptionalSome) =>
-                    Expr::NEOptionalLit(rc(second)),
-                _ => Expr::App(rc(first), vec![rc(second)]),
-            }
+        [expression(Expr::Builtin(Builtin::OptionalNone)),
+                expression(e), expression(rest)..] => {
+            app(Expr::EmptyOptionalLit(rc(e)), rest.map(rc).collect())
         },
-        [expression(first), expression(second), expression(rest)..] => {
-            match first {
-                Expr::Builtin(Builtin::OptionalNone) =>
-                    Expr::App(rc(Expr::EmptyOptionalLit(rc(second))),
-                                 rest.map(rc).collect()),
-                Expr::Builtin(Builtin::OptionalSome) =>
-                    Expr::App(rc(Expr::NEOptionalLit(rc(second))),
-                                 rest.map(rc).collect()),
-                _ => Expr::App(rc(first),
-                                  std::iter::once(rc(second))
-                                    .chain(rest.map(rc))
-                                    .collect()),
-            }
+        [expression(Expr::Builtin(Builtin::OptionalSome)),
+                expression(e), expression(rest)..] => {
+            app(Expr::NEOptionalLit(rc(e)), rest.map(rc).collect())
+        },
+        [expression(first), expression(rest)..] => {
+            app(first, rest.map(rc).collect())
         },
     ));
 
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