From b6201051b2975ece55f000e2b428e69dc35b7d63 Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 01:02:16 +0000
Subject: [PATCH 1/6] Count the type parameters only

---
 .../src/handlers/add_turbo_fish.rs            | 27 ++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index 2872edc9e10..95182d6edef 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -77,7 +77,13 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
         }
     }
 
-    let number_of_arguments = generics.len();
+    let number_of_arguments = generics
+        .iter()
+        .filter(|param| match param {
+            hir::GenericParam::TypeParam(_) => true,
+            _ => false,
+        })
+        .count();
     let fish_head = std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(",");
 
     acc.add(
@@ -339,4 +345,23 @@ fn main() {
             "Add `: _` before assignment operator",
         );
     }
+
+    #[test]
+    fn add_turbo_fish_function_lifetime_parameter() {
+        check_assist(
+            add_turbo_fish,
+            r#"
+fn make<'a, T, A>(t: T, a: A) {}
+fn main() {
+    make$0(5, 2);
+}
+"#,
+            r#"
+fn make<'a, T, A>(t: T, a: A) {}
+fn main() {
+    make::<${0:_,_}>(5, 2);
+}
+"#,
+        );
+    }
 }

From 734193bc23e737191eb6fa66c355af866c0c3fb2 Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 01:09:32 +0000
Subject: [PATCH 2/6] support const params

---
 .../src/handlers/add_turbo_fish.rs            | 21 ++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index 95182d6edef..12d9a9de6d4 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -80,7 +80,7 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     let number_of_arguments = generics
         .iter()
         .filter(|param| match param {
-            hir::GenericParam::TypeParam(_) => true,
+            hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_) => true,
             _ => false,
         })
         .count();
@@ -361,6 +361,25 @@ fn make<'a, T, A>(t: T, a: A) {}
 fn main() {
     make::<${0:_,_}>(5, 2);
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn add_turbo_fish_function_const_parameter() {
+        check_assist(
+            add_turbo_fish,
+            r#"
+fn make<T, const N: usize>(t: T) {}
+fn main() {
+    make$0(3);
+}
+"#,
+            r#"
+fn make<T, const N: usize>(t: T) {}
+fn main() {
+    make::<${0:_,_}>(3);
+}
 "#,
         );
     }

From 76e04290480e872fe59d094118cd341937805d23 Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 12:34:03 +0000
Subject: [PATCH 3/6] concise filtering

---
 crates/ide_assists/src/handlers/add_turbo_fish.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index 12d9a9de6d4..e493e4e192e 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -79,10 +79,7 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
 
     let number_of_arguments = generics
         .iter()
-        .filter(|param| match param {
-            hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_) => true,
-            _ => false,
-        })
+        .filter(|param| matches!(param, hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_)))
         .count();
     let fish_head = std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(",");
 

From 778e71b15fac1a5c7dfff031d79d024eaf99665d Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 12:40:41 +0000
Subject: [PATCH 4/6] fmt

---
 crates/ide_assists/src/handlers/add_turbo_fish.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index e493e4e192e..f67c65d1668 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -79,7 +79,9 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
 
     let number_of_arguments = generics
         .iter()
-        .filter(|param| matches!(param, hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_)))
+        .filter(|param| {
+            matches!(param, hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_))
+        })
         .count();
     let fish_head = std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(",");
 

From 4bcdb053253e82f88d9db7806571887da45599d7 Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 13:17:21 +0000
Subject: [PATCH 5/6] include tabstops

---
 .../src/handlers/add_turbo_fish.rs            | 27 ++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index f67c65d1668..522dacc7627 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -83,7 +83,6 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
             matches!(param, hir::GenericParam::TypeParam(_) | hir::GenericParam::ConstParam(_))
         })
         .count();
-    let fish_head = std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(",");
 
     acc.add(
         AssistId("add_turbo_fish", AssistKind::RefactorRewrite),
@@ -91,10 +90,12 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
         ident.text_range(),
         |builder| match ctx.config.snippet_cap {
             Some(cap) => {
-                let snip = format!("::<${{0:{}}}>", fish_head);
+                let snip = format!("::<{}>", get_snippet_fish_head(number_of_arguments));
                 builder.insert_snippet(cap, ident.text_range().end(), snip)
             }
             None => {
+                let fish_head =
+                    std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(", ");
                 let snip = format!("::<{}>", fish_head);
                 builder.insert(ident.text_range().end(), snip);
             }
@@ -102,6 +103,20 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     )
 }
 
+/// This will create a snippet string with tabstops marked
+fn get_snippet_fish_head(number_of_arguments: usize) -> String {
+    let mut fish_head = String::new();
+    let mut i = 1;
+    while i < number_of_arguments {
+        fish_head.push_str(&format!("${{{}:_}},", i));
+        i = i + 1;
+    }
+
+    // tabstop 0 is a special case and always the last one
+    fish_head.push_str("${0:_}");
+    fish_head
+}
+
 #[cfg(test)]
 mod tests {
     use crate::tests::{check_assist, check_assist_by_label, check_assist_not_applicable};
@@ -140,7 +155,7 @@ fn main() {
             r#"
 fn make<T, A>() -> T {}
 fn main() {
-    make::<${0:_,_}>();
+    make::<${1:_},${0:_}>();
 }
 "#,
         );
@@ -159,7 +174,7 @@ fn main() {
             r#"
 fn make<T, A, B, C, D, E, F>() -> T {}
 fn main() {
-    make::<${0:_,_,_,_,_,_,_}>();
+    make::<${1:_},${2:_},${3:_},${4:_},${5:_},${6:_},${0:_}>();
 }
 "#,
         );
@@ -358,7 +373,7 @@ fn main() {
             r#"
 fn make<'a, T, A>(t: T, a: A) {}
 fn main() {
-    make::<${0:_,_}>(5, 2);
+    make::<${1:_},${0:_}>(5, 2);
 }
 "#,
         );
@@ -377,7 +392,7 @@ fn main() {
             r#"
 fn make<T, const N: usize>(t: T) {}
 fn main() {
-    make::<${0:_,_}>(3);
+    make::<${1:_},${0:_}>(3);
 }
 "#,
         );

From 0a240e31c5327cf509d335d0dfb6a5d97100ac0a Mon Sep 17 00:00:00 2001
From: Jeroen Vannevel <jer_vannevel@outlook.com>
Date: Fri, 7 Jan 2022 13:53:42 +0000
Subject: [PATCH 6/6] succinct code

---
 .../src/handlers/add_turbo_fish.rs            | 21 ++++++++-----------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index 522dacc7627..c3d27f7ea65 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -1,4 +1,5 @@
 use ide_db::defs::{Definition, NameRefClass};
+use itertools::Itertools;
 use syntax::{ast, AstNode, SyntaxKind, T};
 
 use crate::{
@@ -94,8 +95,7 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
                 builder.insert_snippet(cap, ident.text_range().end(), snip)
             }
             None => {
-                let fish_head =
-                    std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(", ");
+                let fish_head = std::iter::repeat("_").take(number_of_arguments).format(", ");
                 let snip = format!("::<{}>", fish_head);
                 builder.insert(ident.text_range().end(), snip);
             }
@@ -105,12 +105,9 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
 
 /// This will create a snippet string with tabstops marked
 fn get_snippet_fish_head(number_of_arguments: usize) -> String {
-    let mut fish_head = String::new();
-    let mut i = 1;
-    while i < number_of_arguments {
-        fish_head.push_str(&format!("${{{}:_}},", i));
-        i = i + 1;
-    }
+    let mut fish_head = (1..number_of_arguments)
+        .format_with("", |i, f| f(&format_args!("${{{}:_}}, ", i)))
+        .to_string();
 
     // tabstop 0 is a special case and always the last one
     fish_head.push_str("${0:_}");
@@ -155,7 +152,7 @@ fn main() {
             r#"
 fn make<T, A>() -> T {}
 fn main() {
-    make::<${1:_},${0:_}>();
+    make::<${1:_}, ${0:_}>();
 }
 "#,
         );
@@ -174,7 +171,7 @@ fn main() {
             r#"
 fn make<T, A, B, C, D, E, F>() -> T {}
 fn main() {
-    make::<${1:_},${2:_},${3:_},${4:_},${5:_},${6:_},${0:_}>();
+    make::<${1:_}, ${2:_}, ${3:_}, ${4:_}, ${5:_}, ${6:_}, ${0:_}>();
 }
 "#,
         );
@@ -373,7 +370,7 @@ fn main() {
             r#"
 fn make<'a, T, A>(t: T, a: A) {}
 fn main() {
-    make::<${1:_},${0:_}>(5, 2);
+    make::<${1:_}, ${0:_}>(5, 2);
 }
 "#,
         );
@@ -392,7 +389,7 @@ fn main() {
             r#"
 fn make<T, const N: usize>(t: T) {}
 fn main() {
-    make::<${1:_},${0:_}>(3);
+    make::<${1:_}, ${0:_}>(3);
 }
 "#,
         );