Hide unit fn return types

5 files changed, 28 insertions, 20 deletions

diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index 13ecd537a..1665e25e4 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -155,7 +155,11 @@ impl HirDisplay for ApplicationTy {
                 let sig = FnSig::from_fn_ptr_substs(&self.parameters);
                 write!(f, "fn(")?;
                 f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
+                write!(f, ")")?;
+                let ret = sig.ret();
+                if *ret != Ty::unit() {
+                    write!(f, " -> {}", ret.display(f.db))?;
+                }
             }
             TypeCtor::FnDef(def) => {
                 let sig = f.db.callable_item_signature(def).subst(&self.parameters);
@@ -180,7 +184,11 @@ impl HirDisplay for ApplicationTy {
                 }
                 write!(f, "(")?;
                 f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
+                write!(f, ")")?;
+                let ret = sig.ret();
+                if *ret != Ty::unit() {
+                    write!(f, " -> {}", ret.display(f.db))?;
+                }
             }
             TypeCtor::Adt(def_id) => {
                 let name = match def_id {
@@ -242,16 +250,16 @@ impl HirDisplay for ApplicationTy {
                 let sig = self.parameters[0]
                     .callable_sig(f.db)
                     .expect("first closure parameter should contain signature");
-                let return_type_hint = sig.ret().display(f.db);
                 if sig.params().is_empty() {
-                    write!(f, "|| -> {}", return_type_hint)?;
+                    write!(f, "||")?;
                 } else if f.omit_verbose_types() {
-                    write!(f, "|{}| -> {}", TYPE_HINT_TRUNCATION, return_type_hint)?;
+                    write!(f, "|{}|", TYPE_HINT_TRUNCATION)?;
                 } else {
                     write!(f, "|")?;
                     f.write_joined(sig.params(), ", ")?;
-                    write!(f, "| -> {}", return_type_hint)?;
+                    write!(f, "|")?;
                 };
+                write!(f, " -> {}", sig.ret().display(f.db))?;
             }
         }
         Ok(())
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 3e3d55c04..b2c971f02 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -407,16 +407,16 @@ fn test() {
     [30; 31) 'x': &Foo
     [39; 41) '{}': ()
     [52; 133) '{     ...oo); }': ()
-    [58; 71) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [58; 71) 'takes_ref_foo': fn takes_ref_foo(&Foo)
     [58; 77) 'takes_...(&Foo)': ()
     [72; 76) '&Foo': &Foo
     [73; 76) 'Foo': Foo
-    [83; 96) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [83; 96) 'takes_ref_foo': fn takes_ref_foo(&Foo)
     [83; 103) 'takes_...&&Foo)': ()
     [97; 102) '&&Foo': &&Foo
     [98; 102) '&Foo': &Foo
     [99; 102) 'Foo': Foo
-    [109; 122) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [109; 122) 'takes_ref_foo': fn takes_ref_foo(&Foo)
     [109; 130) 'takes_...&&Foo)': ()
     [123; 129) '&&&Foo': &&&Foo
     [124; 129) '&&Foo': &&Foo
@@ -484,7 +484,7 @@ fn test() {
     [171; 178) 'loop {}': !
     [176; 178) '{}': ()
     [191; 236) '{     ... }); }': ()
-    [197; 210) 'takes_ref_str': fn takes_ref_str(&str) -> ()
+    [197; 210) 'takes_ref_str': fn takes_ref_str(&str)
     [197; 233) 'takes_...g() })': ()
     [211; 232) '&{ ret...ng() }': &String
     [212; 232) '{ retu...ng() }': String
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 2ee9b8f10..3402e0cb5 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -376,7 +376,7 @@ fn issue_2669() {
         ),
         @r###"
     [147; 262) '{     ...     }': ()
-    [161; 164) 'end': fn end<{unknown}>() -> ()
+    [161; 164) 'end': fn end<{unknown}>()
     [161; 166) 'end()': ()
     [199; 252) '{     ...     }': ()
     [221; 223) '_x': !
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 141f0245a..c2f1ded2f 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -521,7 +521,7 @@ fn test() -> &mut &f64 {
     [88; 89) 'a': u32
     [92; 108) 'unknow...nction': {unknown}
     [92; 110) 'unknow...tion()': u32
-    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
+    [116; 125) 'takes_u32': fn takes_u32(u32)
     [116; 128) 'takes_u32(a)': ()
     [126; 127) 'a': u32
     [138; 139) 'b': i32
@@ -1749,9 +1749,9 @@ fn main() {
     [67; 91) 'Vtable...| {} }': Vtable
     [84; 89) '|| {}': || -> ()
     [87; 89) '{}': ()
-    [101; 102) 'm': fn() -> ()
+    [101; 102) 'm': fn()
     [105; 111) 'vtable': Vtable
-    [105; 118) 'vtable.method': fn() -> ()
+    [105; 118) 'vtable.method': fn()
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index f009a708c..081aa943a 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -263,7 +263,7 @@ fn test() {
     [119; 120) 'S': S<u32>(u32) -> S<u32>
     [119; 129) 'S(unknown)': S<u32>
     [121; 128) 'unknown': u32
-    [135; 138) 'foo': fn foo<S<u32>>(S<u32>) -> ()
+    [135; 138) 'foo': fn foo<S<u32>>(S<u32>)
     [135; 141) 'foo(s)': ()
     [139; 140) 's': S<u32>
     "###
@@ -962,7 +962,7 @@ fn test(x: impl Trait<u64>, y: &impl Trait<u32>) {
     [224; 225) 'S': S<u16>(u16) -> S<u16>
     [224; 228) 'S(1)': S<u16>
     [226; 227) '1': u16
-    [234; 237) 'bar': fn bar(S<u16>) -> ()
+    [234; 237) 'bar': fn bar(S<u16>)
     [234; 240) 'bar(z)': ()
     [238; 239) 'z': S<u16>
     [246; 247) 'x': impl Trait<u64>
@@ -1108,8 +1108,8 @@ fn test() {
     [40; 47) 'loop {}': !
     [45; 47) '{}': ()
     [91; 124) '{     ...foo; }': ()
-    [101; 102) 'f': fn(S) -> ()
-    [118; 121) 'foo': fn foo(S) -> ()
+    [101; 102) 'f': fn(S)
+    [118; 121) 'foo': fn foo(S)
     "###
     );
 }
@@ -1962,7 +1962,7 @@ fn test() -> impl Trait<i32> {
     [229; 241) 'S(default())': S<u32>
     [231; 238) 'default': fn default<u32>() -> u32
     [231; 240) 'default()': u32
-    [247; 250) 'foo': fn foo(S<u32>) -> ()
+    [247; 250) 'foo': fn foo(S<u32>)
     [247; 254) 'foo(s1)': ()
     [251; 253) 's1': S<u32>
     [264; 265) 'x': i32
@@ -2012,7 +2012,7 @@ fn main() {
     [147; 149) '_v': F
     [192; 195) '{ }': ()
     [207; 238) '{     ... }); }': ()
-    [213; 223) 'f::<(), _>': fn f<(), |&()| -> ()>(|&()| -> ()) -> ()
+    [213; 223) 'f::<(), _>': fn f<(), |&()| -> ()>(|&()| -> ())
     [213; 235) 'f::<()... z; })': ()
     [224; 234) '|z| { z; }': |&()| -> ()
     [225; 226) 'z': &()