Implement catch

src/expr.rs

@@ -253,8 +253,16 @@ fn format_expr(expr: &ast::Expr,
                      context.config.max_width(),
                      shape)
         }
-        // FIXME(#1537)
-        ast::ExprKind::Catch(..) => unimplemented!(),
+        ast::ExprKind::Catch(ref block) => {
+            if let rewrite @ Some(_) = try_one_line_block(context, shape, "do catch ", block) {
+                return rewrite;
+            }
+            // 9 = `do catch `
+            let budget = shape.width.checked_sub(9).unwrap_or(0);
+            Some(format!("{}{}",
+                         "do catch ",
+                         try_opt!(block.rewrite(&context, Shape::legacy(budget, shape.indent)))))
+        }
     };
     match (attr_rw, expr_rw) {
         (Some(attr_str), Some(expr_str)) => {
@@ -268,6 +276,22 @@ fn format_expr(expr: &ast::Expr,
     }
 }
 
+fn try_one_line_block(context: &RewriteContext,
+                      shape: Shape,
+                      prefix: &str,
+                      block: &ast::Block)
+                      -> Option<String> {
+    if is_simple_block(block, context.codemap) {
+        let expr_shape = Shape::legacy(shape.width - prefix.len(), shape.indent);
+        let expr_str = try_opt!(block.stmts[0].rewrite(context, expr_shape));
+        let result = format!("{}{{ {} }}", prefix, expr_str);
+        if result.len() <= shape.width && !result.contains('\n') {
+            return Some(result);
+        }
+    }
+    None
+}
+
 pub fn rewrite_pair<LHS, RHS>(lhs: &LHS,
                               rhs: &RHS,
                               prefix: &str,
@@ -622,9 +646,7 @@ fn rewrite_closure(capture: ast::CaptureBy,
         // means we must re-format.
         let block_shape = shape.block().with_max_width(context.config);
         let block_str = try_opt!(block.rewrite(&context, block_shape));
-        Some(format!("{} {}",
-                     prefix,
-                     try_opt!(block_str.rewrite(context, block_shape))))
+        Some(format!("{} {}", prefix, block_str))
     }
 }
 
@@ -689,24 +711,13 @@ impl Rewrite for ast::Block {
                 } else {
                     "unsafe ".to_owned()
                 };
-
-                if is_simple_block(self, context.codemap) && prefix.len() < shape.width {
-                    let expr_str =
-                        self.stmts[0].rewrite(context,
-                                              Shape::legacy(shape.width - prefix.len(),
-                                                            shape.indent));
-                    let expr_str = try_opt!(expr_str);
-                    let result = format!("{}{{ {} }}", prefix, expr_str);
-                    if result.len() <= shape.width && !result.contains('\n') {
-                        return Some(result);
-                    }
+                if let result @ Some(_) = try_one_line_block(context, shape, &prefix, self) {
+                    return result;
                 }
-
                 prefix
             }
             ast::BlockCheckMode::Default => {
                 visitor.last_pos = self.span.lo;
-
                 String::new()
             }
         };

tests/source/catch.rs

@@ -0,0 +1,27 @@
+#![feature(catch_expr)]
+
+fn main() {
+    let x = do catch {
+        foo()?
+    };
+
+    let x = do catch /* Invisible comment */ { foo()? };
+
+    let x = do catch {
+        unsafe { foo()? }
+    };
+
+    let y = match (do catch {
+        foo()?
+    }) {
+        _ => (),
+    };
+
+    do catch {
+        foo()?;
+    };
+
+    do catch {
+        // Regular do catch block
+    };
+}

tests/target/catch.rs

@@ -0,0 +1,21 @@
+#![feature(catch_expr)]
+
+fn main() {
+    let x = do catch { foo()? };
+
+    let x = do catch /* Invisible comment */ { foo()? };
+
+    let x = do catch { unsafe { foo()? } };
+
+    let y = match (do catch { foo()? }) {
+        _ => (),
+    };
+
+    do catch {
+        foo()?;
+    };
+
+    do catch {
+        // Regular do catch block
+    };
+}

tests/target/closure.rs

@@ -109,8 +109,10 @@ fn foo() {
 
 fn issue1405() {
     open_raw_fd(fd, b'r').and_then(|file| {
-        Capture::new_raw(None, |_, err| unsafe { raw::pcap_fopen_offline(file, err) })
-    });
+                                       Capture::new_raw(None, |_, err| unsafe {
+            raw::pcap_fopen_offline(file, err)
+        })
+                                   });
 }
 
 fn issue1466() {

tests/target/match.rs

@@ -326,11 +326,10 @@ fn issue1371() {
              sfEvtGainedFocus => GainedFocus,
              sfEvtTextEntered => {
                  TextEntered {
-                     unicode:
-                         unsafe {
-                             ::std::char::from_u32((*event.text.as_ref()).unicode)
-                                 .expect("Invalid unicode encountered on TextEntered event")
-                         },
+                     unicode: unsafe {
+                         ::std::char::from_u32((*event.text.as_ref()).unicode)
+                             .expect("Invalid unicode encountered on TextEntered event")
+                     },
                  }
              }
              sfEvtKeyPressed => {