Merge pull request #1156 from sinkuu/break_if_let

Prefer line break at `=`/`in`

src/expr.rs

@@ -1322,20 +1322,28 @@ fn rewrite_pat_expr(context: &RewriteContext,
                                         offset + extra_offset + spacer.len());
 
         if let Some(expr_string) = expr_rewrite {
-            result.push_str(spacer);
-            result.push_str(&expr_string);
-            return Some(result);
+            let pat_simple =
+                pat.and_then(|p| p.rewrite(context, context.config.max_width, Indent::empty()))
+                    .map(|s| pat_is_simple(&s));
+
+            if pat.is_none() || pat_simple.unwrap_or(false) || !expr_string.contains('\n') {
+                result.push_str(spacer);
+                result.push_str(&expr_string);
+                return Some(result);
+            }
         }
     }
 
+    let nested = context.nested_context();
+
     // The expression won't fit on the current line, jump to next.
     result.push('\n');
-    result.push_str(&pat_offset.to_string(context.config));
+    result.push_str(&nested.block_indent.to_string(context.config));
 
     let expr_rewrite =
-        expr.rewrite(context,
-                     try_opt!(context.config.max_width.checked_sub(pat_offset.width())),
-                     pat_offset);
+        expr.rewrite(&nested,
+                     try_opt!(context.config.max_width.checked_sub(nested.block_indent.width())),
+                     nested.block_indent);
     result.push_str(&try_opt!(expr_rewrite));
 
     Some(result)

src/items.rs

@@ -568,7 +568,7 @@ fn format_impl_ref_and_type(context: &RewriteContext,
                             split_at_for: bool)
                             -> Option<String> {
     if let ast::ItemKind::Impl(unsafety, polarity, ref generics, ref trait_ref, ref self_ty, _) =
-           item.node {
+        item.node {
         let mut result = String::new();
 
         result.push_str(&*format_visibility(&item.vis));
@@ -670,7 +670,7 @@ pub fn format_struct(context: &RewriteContext,
 
 pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent) -> Option<String> {
     if let ast::ItemKind::Trait(unsafety, ref generics, ref type_param_bounds, ref trait_items) =
-           item.node {
+        item.node {
         let mut result = String::new();
         let header = format!("{}{}trait {}",
                              format_visibility(&item.vis),

tests/source/expr.rs

@@ -285,3 +285,16 @@ fn complex_if_else() {
         yo();
     }
 }
+
+fn issue1106() {
+    {
+    if let hir::ItemEnum(ref enum_def, ref generics) = self.ast_map.expect_item(enum_node_id).node {
+    }
+    }
+
+    for entry in
+    WalkDir::new(path)
+        .into_iter()
+        .filter_entry(|entry| exclusions.filter_entry(entry)) {
+    }
+}

tests/target/expr.rs

@@ -55,8 +55,8 @@ fn foo() -> bool {
     }
 
     if let (some_very_large,
-            tuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuple) = 1111 +
-                                                                                         2222 {}
+            tuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuple) =
+        1111 + 2222 {}
 
     if let (some_very_large,
             tuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuple) = 1 + 2 + 3 {
@@ -283,10 +283,23 @@ fn complex_if_else() {
     } else if xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx + xxxxxxxx {
         yo();
     } else if let Some(x) =
-                  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx {
+        xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx {
         ha();
     } else if xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx +
               xxxxxxxxx {
         yo();
     }
 }
+
+fn issue1106() {
+    {
+        if let hir::ItemEnum(ref enum_def, ref generics) =
+            self.ast_map.expect_item(enum_node_id).node {
+        }
+    }
+
+    for entry in WalkDir::new(path)
+        .into_iter()
+        .filter_entry(|entry| exclusions.filter_entry(entry)) {
+    }
+}

tests/target/loop.rs

@@ -21,8 +21,8 @@ fn main() {
     while aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa {
     }
 
-    'b: for xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx in some_iter(arg1,
-                                                                                        arg2) {
+    'b: for xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx in
+        some_iter(arg1, arg2) {
         // do smth
     }