4 files changed, 243 insertions, 3 deletions

diff --git a/crates/ra_ide/src/completion/complete_postfix.rs b/crates/ra_ide/src/completion/complete_postfix.rs
index 6a0f0c72e..c5c4426cc 100644
--- a/crates/ra_ide/src/completion/complete_postfix.rs
+++ b/crates/ra_ide/src/completion/complete_postfix.rs
@@ -14,6 +14,7 @@ use crate::{
     },
     CompletionItem,
 };
+use ra_assists::utils::TryEnum;
 
 pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.config.enable_postfix_completions {
@@ -38,7 +39,52 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         None => return,
     };
 
-    if receiver_ty.is_bool() || receiver_ty.is_unknown() {
+    if let Some(try_enum) = TryEnum::from_ty(&ctx.sema, &receiver_ty) {
+        match try_enum {
+            TryEnum::Result => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "ifl",
+                    "if let Ok {}",
+                    &format!("if let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "while",
+                    "while let Ok {}",
+                    &format!("while let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+            }
+            TryEnum::Option => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "ifl",
+                    "if let Some {}",
+                    &format!("if let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "while",
+                    "while let Some {}",
+                    &format!("while let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+            }
+        }
+    } else if receiver_ty.is_bool() || receiver_ty.is_unknown() {
         postfix_snippet(
             ctx,
             cap,
@@ -236,6 +282,164 @@ mod tests {
     }
 
     #[test]
+    fn postfix_completion_works_for_option() {
+        assert_debug_snapshot!(
+            do_postfix_completion(
+                r#"
+                enum Option<T> {
+                    Some(T),
+                    None,
+                }
+
+                fn main() {
+                    let bar = Option::Some(true);
+                    bar.<|>
+                }
+                "#,
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "box",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "Box::new(bar)",
+                detail: "Box::new(expr)",
+            },
+            CompletionItem {
+                label: "dbg",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "dbg!(bar)",
+                detail: "dbg!(expr)",
+            },
+            CompletionItem {
+                label: "ifl",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "if let Some($1) = bar {\n    $0\n}",
+                detail: "if let Some {}",
+            },
+            CompletionItem {
+                label: "match",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "match bar {\n    ${1:_} => {$0\\},\n}",
+                detail: "match expr {}",
+            },
+            CompletionItem {
+                label: "not",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "!bar",
+                detail: "!expr",
+            },
+            CompletionItem {
+                label: "ref",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "&bar",
+                detail: "&expr",
+            },
+            CompletionItem {
+                label: "refm",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "&mut bar",
+                detail: "&mut expr",
+            },
+            CompletionItem {
+                label: "while",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "while let Some($1) = bar {\n    $0\n}",
+                detail: "while let Some {}",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn postfix_completion_works_for_result() {
+        assert_debug_snapshot!(
+            do_postfix_completion(
+                r#"
+                enum Result<T, E> {
+                    Ok(T),
+                    Err(E),
+                }
+
+                fn main() {
+                    let bar = Result::Ok(true);
+                    bar.<|>
+                }
+                "#,
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "box",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "Box::new(bar)",
+                detail: "Box::new(expr)",
+            },
+            CompletionItem {
+                label: "dbg",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "dbg!(bar)",
+                detail: "dbg!(expr)",
+            },
+            CompletionItem {
+                label: "ifl",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "if let Ok($1) = bar {\n    $0\n}",
+                detail: "if let Ok {}",
+            },
+            CompletionItem {
+                label: "match",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "match bar {\n    ${1:_} => {$0\\},\n}",
+                detail: "match expr {}",
+            },
+            CompletionItem {
+                label: "not",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "!bar",
+                detail: "!expr",
+            },
+            CompletionItem {
+                label: "ref",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "&bar",
+                detail: "&expr",
+            },
+            CompletionItem {
+                label: "refm",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "&mut bar",
+                detail: "&mut expr",
+            },
+            CompletionItem {
+                label: "while",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "while let Ok($1) = bar {\n    $0\n}",
+                detail: "while let Ok {}",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
     fn some_postfix_completions_ignored() {
         assert_debug_snapshot!(
             do_postfix_completion(
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 4c27aade4..635fe5cf9 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -33,6 +33,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="keyword">pub</span> <span class="field declaration">y</span>: <span class="builtin_type">i32</span>,
 }
 
+<span class="keyword">trait</span> <span class="trait declaration">Bar</span> {
+    <span class="keyword">fn</span> <span class="function declaration">bar</span>(&<span class="keyword">self</span>) -&gt; <span class="builtin_type">i32</span>;
+}
+
+<span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> {
+    <span class="keyword">fn</span> <span class="function declaration">bar</span>(&<span class="keyword">self</span>) -&gt; <span class="builtin_type">i32</span> {
+        <span class="keyword">self</span>.<span class="field">x</span>
+    }
+}
+
 <span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable">STATIC_MUT</span>: <span class="builtin_type">i32</span> = <span class="numeric_literal">0</span>;
 
 <span class="keyword">fn</span> <span class="function declaration">foo</span>&lt;<span class="lifetime declaration">'a</span>, <span class="type_param declaration">T</span>&gt;() -&gt; <span class="type_param">T</span> {
@@ -63,6 +73,10 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
         <span class="static mutable">STATIC_MUT</span> = <span class="numeric_literal">1</span>;
     }
 
+    <span class="keyword control">for</span> <span class="variable declaration">e</span> <span class="keyword control">in</span> <span class="variable mutable">vec</span> {
+        <span class="comment">// Do nothing</span>
+    }
+
     <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> = <span class="numeric_literal">42</span>;
     <span class="keyword">let</span> <span class="variable declaration mutable">y</span> = &<span class="keyword">mut</span> <span class="variable mutable">x</span>;
     <span class="keyword">let</span> <span class="variable declaration">z</span> = &<span class="variable mutable">y</span>;
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index d53a39f57..be57eeb0a 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -403,12 +403,13 @@ fn highlight_element(
                 T![break]
                 | T![continue]
                 | T![else]
-                | T![for]
                 | T![if]
                 | T![loop]
                 | T![match]
                 | T![return]
-                | T![while] => h | HighlightModifier::ControlFlow,
+                | T![while]
+                | T![in] => h | HighlightModifier::ControlFlow,
+                T![for] if !is_child_of_impl(element) => h | HighlightModifier::ControlFlow,
                 T![unsafe] => h | HighlightModifier::Unsafe,
                 _ => h,
             }
@@ -432,6 +433,13 @@ fn highlight_element(
     }
 }
 
+fn is_child_of_impl(element: SyntaxElement) -> bool {
+    match element.parent() {
+        Some(e) => e.kind() == IMPL_DEF,
+        _ => false,
+    }
+}
+
 fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
     match def {
         Definition::Macro(_) => HighlightTag::Macro,
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
index 13894869c..eb43a23da 100644
--- a/crates/ra_ide/src/syntax_highlighting/tests.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -17,6 +17,16 @@ struct Foo {
     pub y: i32,
 }
 
+trait Bar {
+    fn bar(&self) -> i32;
+}
+
+impl Bar for Foo {
+    fn bar(&self) -> i32 {
+        self.x
+    }
+}
+
 static mut STATIC_MUT: i32 = 0;
 
 fn foo<'a, T>() -> T {
@@ -47,6 +57,10 @@ fn main() {
         STATIC_MUT = 1;
     }
 
+    for e in vec {
+        // Do nothing
+    }
+
     let mut x = 42;
     let y = &mut x;
     let z = &y;