Improve heuristics for match arm body placement

6 files changed, 386 insertions, 273 deletions

diff --git a/src/expr.rs b/src/expr.rs
index 79e03e644e4..29966d09da9 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -15,7 +15,7 @@ use Indent;
 use rewrite::{Rewrite, RewriteContext};
 use lists::{write_list, itemize_list, ListFormatting, SeparatorTactic, ListTactic};
 use string::{StringFormat, rewrite_string};
-use utils::{span_after, extra_offset, first_line_width, last_line_width, wrap_str, binary_search};
+use utils::{span_after, extra_offset, last_line_width, wrap_str, binary_search};
 use visitor::FmtVisitor;
 use config::{StructLitStyle, MultilineStyle};
 use comment::{FindUncommented, rewrite_comment, contains_comment};
@@ -352,9 +352,9 @@ fn rewrite_closure(capture: ast::CaptureClause,
     Some(format!("{} {}", prefix, try_opt!(body_rewrite)))
 }
 
-fn nop_block_collapse(block_str: Option<String>) -> Option<String> {
+fn nop_block_collapse(block_str: Option<String>, budget: usize) -> Option<String> {
     block_str.map(|block_str| {
-        if block_str.starts_with("{") &&
+        if block_str.starts_with("{") && budget >= 2 &&
            (block_str[1..].find(|c: char| !c.is_whitespace()).unwrap() == block_str.len() - 2) {
             "{}".to_owned()
         } else {
@@ -889,36 +889,64 @@ impl Rewrite for ast::Arm {
 
         // Let's try and get the arm body on the same line as the condition.
         // 4 = ` => `.len()
-        if context.config.max_width > line_start + comma.len() + 4 {
+        let same_line_body = if context.config.max_width > line_start + comma.len() + 4 {
             let budget = context.config.max_width - line_start - comma.len() - 4;
-            if let Some(ref body_str) = nop_block_collapse(body.rewrite(context,
-                                                                        budget,
-                                                                        line_indent + 4)) {
-                if first_line_width(body_str) <= budget {
+            let rewrite = nop_block_collapse(body.rewrite(context, budget, line_indent + 4),
+                                             budget);
+
+            match rewrite {
+                Some(ref body_str) if body_str.len() <= budget || comma.is_empty() =>
                     return Some(format!("{}{} => {}{}",
                                         attr_str.trim_left(),
                                         pats_str,
                                         body_str,
-                                        comma));
-                }
+                                        comma)),
+                _ => rewrite,
             }
-        }
+        } else {
+            None
+        };
 
         // We have to push the body to the next line.
-        if comma.is_empty() {
+        if let ast::ExprBlock(_) = body.node {
             // We're trying to fit a block in, but it still failed, give up.
             return None;
         }
 
         let body_budget = try_opt!(width.checked_sub(context.config.tab_spaces));
-        let body_str = try_opt!(nop_block_collapse(body.rewrite(context,
-                                                                body_budget,
-                                                                context.block_indent)));
-        Some(format!("{}{} =>\n{}{},",
-                     attr_str.trim_left(),
-                     pats_str,
-                     offset.block_indent(context.config).to_string(context.config),
-                     body_str))
+        let next_line_body = nop_block_collapse(body.rewrite(context,
+                                                             body_budget,
+                                                             context.block_indent
+                                                                    .block_indent(context.config)),
+                                                body_budget);
+
+        let (body_str, break_line) = try_opt!(match_arm_heuristic(same_line_body.as_ref()
+                                                                                .map(|x| &x[..]),
+                                                                  next_line_body.as_ref()
+                                                                                .map(|x| &x[..])));
+
+        let spacer = if break_line {
+            format!("\n{}", offset.block_indent(context.config).to_string(context.config))
+        } else {
+            " ".to_owned()
+        };
+
+        Some(format!("{}{} =>{}{},", attr_str.trim_left(), pats_str, spacer, body_str))
+    }
+}
+
+// Takes two possible rewrites for the match arm body and chooses the "nicest".
+// Bool marks break line or no.
+fn match_arm_heuristic<'a>(former: Option<&'a str>,
+                           latter: Option<&'a str>)
+                           -> Option<(&'a str, bool)> {
+    match (former, latter) {
+        (Some(f), None) => Some((f, false)),
+        (Some(f), Some(l)) if f.chars().filter(|&c| c == '\n').count() <=
+                              l.chars().filter(|&c| c == '\n').count() => {
+            Some((f, false))
+        }
+        (_, l) => l.map(|s| (s, true)),
     }
 }
 
diff --git a/src/items.rs b/src/items.rs
index efd2c852c3e..ec79040f59c 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -969,8 +969,8 @@ impl<'a> FmtVisitor<'a> {
 
         let extra_indent = match self.config.where_indent {
             BlockIndentStyle::Inherit => Indent::empty(),
-            BlockIndentStyle::Tabbed | BlockIndentStyle::Visual => Indent::new(config.tab_spaces,
-                                                                               0),
+            BlockIndentStyle::Tabbed | BlockIndentStyle::Visual =>
+                Indent::new(config.tab_spaces, 0),
         };
 
         let context = self.get_context();
diff --git a/tests/source/expr.rs b/tests/source/expr.rs
index fc34f799d7d..96ad42cd77d 100644
--- a/tests/source/expr.rs
+++ b/tests/source/expr.rs
@@ -130,125 +130,6 @@ fn issue184(source: &str) {
     }
 }
 
-fn matches() {
-    match 1 {
-        1 => 1, // foo
-        2 => 2,
-        // bar
-        3 => 3,
-        _ => 0 // baz
-    }
-}
-
-fn issue339() {
-    match a {
-        b => {}
-        c => { }
-        d => {
-        }
-        e => {
-
-
-
-        }
-        // collapsing here is safe
-        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff => {
-        }
-        // collapsing here exceeds line length
-        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffg => {
-        }
-        h => { // comment above block
-        }
-        i => {
-        } // comment below block
-        j => {
-            // comment inside block
-        }
-        j2 => {
-            // comments inside...
-        } // ... and after
-        // TODO uncomment when vertical whitespace is handled better
-        // k => {
-        //
-        //     // comment with WS above
-        // }
-        // l => {
-        //     // comment with ws below
-        //     
-        // }
-        m => {
-        } n => { } o =>
-        {
-
-        }
-        p => { // Dont collapse me
-        } q => { } r =>
-        {
-
-        }
-        s => 0, // s comment
-        // t comment
-        t => 1,
-        u => 2,
-        // TODO uncomment when block-support exists
-        // v => {
-        // } /* funky block
-        //    * comment */
-        // final comment
-    }
-}
-
-fn issue355() {
-    match mac {
-        a => println!("a", b),
-        b => vec!(1, 2),
-        c => vec!(3; 4),
-        d => {
-            println!("a", b)
-        }
-        e => {
-            vec!(1, 2)
-        }
-        f => {
-            vec!(3; 4)
-        }
-        h => println!("a", b), // h comment
-        i => vec!(1, 2), // i comment
-        j => vec!(3; 4), // j comment
-        // k comment
-        k => println!("a", b),
-        // l comment
-        l => vec!(1, 2),
-        // m comment
-        m => vec!(3; 4),
-        // Rewrite splits macro
-        nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn => println!("a", b),
-        // Rewrite splits macro
-        oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo => vec!(1, 2),
-        // Macro support fails to recognise this macro as splitable
-        // We push the whole expr to a new line, TODO split this macro as well
-        pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp => vec!(3; 4),
-        // q, r and s: Rewrite splits match arm
-        qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq => println!("a", b),
-        rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr => vec!(1, 2),
-        ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss => vec!(3; 4),
-        // Funky bracketing styles
-        t =>      println!{"a", b},
-        u => vec!{1, 2},
-        v => vec!{3; 4},
-        w => println!["a", b],
-        x =>      vec![1, 2],
-        y =>vec![3; 4],
-        // Brackets with comments
-        tc => println!{"a", b}, // comment
-        uc => vec!{1, 2}, // comment
-        vc =>vec!{3; 4}, // comment
-        wc =>println!["a", b], // comment
-        xc => vec![1,2], // comment
-        yc =>        vec![3; 4], // comment
-    }
-}
-
 fn arrays() {
     let x = [0,
          1,
diff --git a/tests/source/match.rs b/tests/source/match.rs
new file mode 100644
index 00000000000..9fc32ef1904
--- /dev/null
+++ b/tests/source/match.rs
@@ -0,0 +1,211 @@
+// Match expressions.
+
+fn foo() {
+    // A match expression.
+    match x {
+        // Some comment.
+        a => foo(),
+        b if 0 < 42 => foo(),
+        c => { // Another comment.
+            // Comment.
+            an_expression;
+            foo()
+        }
+        // Perhaps this should introduce braces?
+        Foo(ref bar) =>
+            aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
+        Pattern1 | Pattern2 | Pattern3 => false,
+        Paternnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn |
+        Paternnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn => {
+            blah
+        }
+        Patternnnnnnnnnnnnnnnnnnn |
+        Patternnnnnnnnnnnnnnnnnnn |
+        Patternnnnnnnnnnnnnnnnnnn |
+        Patternnnnnnnnnnnnnnnnnnn => meh,
+
+        Patternnnnnnnnnnnnnnnnnnn |
+        Patternnnnnnnnnnnnnnnnnnn if looooooooooooooooooong_guard => meh,
+
+        Patternnnnnnnnnnnnnnnnnnnnnnnnn |
+        Patternnnnnnnnnnnnnnnnnnnnnnnnn if looooooooooooooooooooooooooooooooooooooooong_guard =>
+            meh,
+
+        // Test that earlier patterns can take the guard space
+        (aaaa, bbbbb, ccccccc, aaaaa, bbbbbbbb, cccccc, aaaa, bbbbbbbb, cccccc, dddddd) |
+        Patternnnnnnnnnnnnnnnnnnnnnnnnn if loooooooooooooooooooooooooooooooooooooooooong_guard => {}
+
+        _ => {}
+        ast::PathParameters::AngleBracketedParameters(ref data) if data.lifetimes.len() > 0 ||
+                                                                   data.types.len() > 0 ||
+                                                                   data.bindings.len() > 0 => {}
+    }
+
+    let whatever = match something {
+        /// DOC COMMENT!
+        Some(_) => 42,
+        // Comment on an attribute.
+        #[an_attribute]
+        // Comment after an attribute.
+        None => 0,
+        #[rustfmt_skip]
+        Blurb     =>     {                  }
+    };
+}
+
+// Test that a match on an overflow line is laid out properly.
+fn main() {
+    let sub_span =
+        match xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx {
+            Some(sub_span) => Some(sub_span),
+            None => sub_span,
+        };
+}
+
+// Test that one-line bodies align.
+fn main() {
+    match r {
+        Variableeeeeeeeeeeeeeeeee => (    "variable",
+                                      vec!("id", "name", "qualname",
+                                           "value", "type", "scopeid"),
+                                      true,
+                                      true),
+        Enummmmmmmmmmmmmmmmmmmmm => ("enum",
+                                     vec!("id","qualname","scopeid","value"),
+                                     true,
+                                     true),
+        Variantttttttttttttttttttttttt => ("variant",
+                                           vec!("id",
+                                                "name",
+                                                "qualname",
+                                                "type",
+                                                "value",
+                                                "scopeid"),
+                                           true,
+                                           true),
+    }
+}
+
+fn matches() {
+    match 1 {
+        1 => 1, // foo
+        2 => 2,
+        // bar
+        3 => 3,
+        _ => 0 // baz
+    }
+}
+
+fn issue339() {
+    match a {
+        b => {}
+        c => { }
+        d => {
+        }
+        e => {
+
+
+
+        }
+        // collapsing here is safe
+        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff => {
+        }
+        // collapsing here exceeds line length
+        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffg => {
+        }
+        h => { // comment above block
+        }
+        i => {
+        } // comment below block
+        j => {
+            // comment inside block
+        }
+        j2 => {
+            // comments inside...
+        } // ... and after
+        // TODO uncomment when vertical whitespace is handled better
+        // k => {
+        //
+        //     // comment with WS above
+        // }
+        // l => {
+        //     // comment with ws below
+        //     
+        // }
+        m => {
+        } n => { } o =>
+        {
+
+        }
+        p => { // Dont collapse me
+        } q => { } r =>
+        {
+
+        }
+        s => 0, // s comment
+        // t comment
+        t => 1,
+        u => 2,
+        // TODO uncomment when block-support exists
+        // v => {
+        // } /* funky block
+        //    * comment */
+        // final comment
+    }
+}
+
+fn issue355() {
+    match mac {
+        a => println!("a", b),
+        b => vec!(1, 2),
+        c => vec!(3; 4),
+        d => {
+            println!("a", b)
+        }
+        e => {
+            vec!(1, 2)
+        }
+        f => {
+            vec!(3; 4)
+        }
+        h => println!("a", b), // h comment
+        i => vec!(1, 2), // i comment
+        j => vec!(3; 4), // j comment
+        // k comment
+        k => println!("a", b),
+        // l comment
+        l => vec!(1, 2),
+        // m comment
+        m => vec!(3; 4),
+        // Rewrite splits macro
+        nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn => println!("a", b),
+        // Rewrite splits macro
+        oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo => vec!(1, 2),
+        // Macro support fails to recognise this macro as splitable
+        // We push the whole expr to a new line, TODO split this macro as well
+        pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp => vec!(3; 4),
+        // q, r and s: Rewrite splits match arm
+        qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq => println!("a", b),
+        rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr => vec!(1, 2),
+        ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss => vec!(3; 4),
+        // Funky bracketing styles
+        t =>      println!{"a", b},
+        u => vec!{1, 2},
+        v => vec!{3; 4},
+        w => println!["a", b],
+        x =>      vec![1, 2],
+        y =>vec![3; 4],
+        // Brackets with comments
+        tc => println!{"a", b}, // comment
+        uc => vec!{1, 2}, // comment
+        vc =>vec!{3; 4}, // comment
+        wc =>println!["a", b], // comment
+        xc => vec![1,2], // comment
+        yc =>        vec![3; 4], // comment
+        yd =>
+            looooooooooooooooooooooooooooooooooooooooooooooooooooooooong_func(aaaaaaaaaa,
+                                                                              bbbbbbbbbb,
+                                                                              cccccccccc,
+                                                                              dddddddddd),
+    }
+}
diff --git a/tests/target/expr.rs b/tests/target/expr.rs
index 34205819f60..f31f27f59d4 100644
--- a/tests/target/expr.rs
+++ b/tests/target/expr.rs
@@ -167,121 +167,6 @@ fn issue184(source: &str) {
     }
 }
 
-fn matches() {
-    match 1 {
-        1 => 1, // foo
-        2 => 2,
-        // bar
-        3 => 3,
-        _ => 0, // baz
-    }
-}
-
-fn issue339() {
-    match a {
-        b => {}
-        c => {}
-        d => {}
-        e => {}
-        // collapsing here is safe
-        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff => {}
-        // collapsing here exceeds line length
-        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffg => {
-        }
-        h => { // comment above block
-        }
-        i => {} // comment below block
-        j => {
-            // comment inside block
-        }
-        j2 => {
-            // comments inside...
-        } // ... and after
-        // TODO uncomment when vertical whitespace is handled better
-        // k => {
-        //
-        //     // comment with WS above
-        // }
-        // l => {
-        //     // comment with ws below
-        //
-        // }
-        m => {}
-        n => {}
-        o => {}
-        p => { // Dont collapse me
-        }
-        q => {}
-        r => {}
-        s => 0, // s comment
-        // t comment
-        t => 1,
-        u => 2,
-        // TODO uncomment when block-support exists
-        // v => {
-        // } /* funky block
-        //    * comment */
-        // final comment
-    }
-}
-
-fn issue355() {
-    match mac {
-        a => println!("a", b),
-        b => vec!(1, 2),
-        c => vec!(3; 4),
-        d => {
-            println!("a", b)
-        }
-        e => {
-            vec!(1, 2)
-        }
-        f => {
-            vec!(3; 4)
-        }
-        h => println!("a", b), // h comment
-        i => vec!(1, 2), // i comment
-        j => vec!(3; 4), // j comment
-        // k comment
-        k => println!("a", b),
-        // l comment
-        l => vec!(1, 2),
-        // m comment
-        m => vec!(3; 4),
-        // Rewrite splits macro
-        nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn => println!("a",
-                                                                                             b),
-        // Rewrite splits macro
-        oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo => vec!(1,
-                                                                                               2),
-        // Macro support fails to recognise this macro as splitable
-        // We push the whole expr to a new line, TODO split this macro as well
-        pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp =>
-            vec!(3; 4),
-        // q, r and s: Rewrite splits match arm
-        qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq =>
-            println!("a", b),
-        rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr =>
-            vec!(1, 2),
-        ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss =>
-            vec!(3; 4),
-        // Funky bracketing styles
-        t => println!{"a", b},
-        u => vec!{1, 2},
-        v => vec!{3; 4},
-        w => println!["a", b],
-        x => vec![1, 2],
-        y => vec![3; 4],
-        // Brackets with comments
-        tc => println!{"a", b}, // comment
-        uc => vec!{1, 2}, // comment
-        vc => vec!{3; 4}, // comment
-        wc => println!["a", b], // comment
-        xc => vec![1, 2], // comment
-        yc => vec![3; 4], // comment
-    }
-}
-
 fn arrays() {
     let x = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 7, 8, 9, 0, 1, 2, 3, 4,
              5, 6, 7, 8, 9, 0];
diff --git a/tests/target/match.rs b/tests/target/match.rs
index 36d91b785f4..3a8bee35aac 100644
--- a/tests/target/match.rs
+++ b/tests/target/match.rs
@@ -65,22 +65,130 @@ fn main() {
 // Test that one-line bodies align.
 fn main() {
     match r {
-        Variableeeeeeeeeeeeeeeeee => ("variable",
-                                      vec!("id", "name", "qualname", "value", "type", "scopeid"),
-                                      true,
-                                      true),
-        Enummmmmmmmmmmmmmmmmmmmm => ("enum",
-                                     vec!("id", "qualname", "scopeid", "value"),
-                                     true,
-                                     true),
-        Variantttttttttttttttttttttttt => ("variant",
-                                           vec!("id",
-                                                "name",
-                                                "qualname",
-                                                "type",
-                                                "value",
-                                                "scopeid"),
-                                           true,
-                                           true),
+        Variableeeeeeeeeeeeeeeeee =>
+            ("variable", vec!("id", "name", "qualname", "value", "type", "scopeid"), true, true),
+        Enummmmmmmmmmmmmmmmmmmmm =>
+            ("enum", vec!("id", "qualname", "scopeid", "value"), true, true),
+        Variantttttttttttttttttttttttt =>
+            ("variant", vec!("id", "name", "qualname", "type", "value", "scopeid"), true, true),
+    }
+}
+
+fn matches() {
+    match 1 {
+        1 => 1, // foo
+        2 => 2,
+        // bar
+        3 => 3,
+        _ => 0, // baz
+    }
+}
+
+fn issue339() {
+    match a {
+        b => {}
+        c => {}
+        d => {}
+        e => {}
+        // collapsing here is safe
+        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff => {}
+        // collapsing here exceeds line length
+        ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffg => {
+        }
+        h => { // comment above block
+        }
+        i => {} // comment below block
+        j => {
+            // comment inside block
+        }
+        j2 => {
+            // comments inside...
+        } // ... and after
+        // TODO uncomment when vertical whitespace is handled better
+        // k => {
+        //
+        //     // comment with WS above
+        // }
+        // l => {
+        //     // comment with ws below
+        //
+        // }
+        m => {}
+        n => {}
+        o => {}
+        p => { // Dont collapse me
+        }
+        q => {}
+        r => {}
+        s => 0, // s comment
+        // t comment
+        t => 1,
+        u => 2,
+        // TODO uncomment when block-support exists
+        // v => {
+        // } /* funky block
+        //    * comment */
+        // final comment
+    }
+}
+
+fn issue355() {
+    match mac {
+        a => println!("a", b),
+        b => vec!(1, 2),
+        c => vec!(3; 4),
+        d => {
+            println!("a", b)
+        }
+        e => {
+            vec!(1, 2)
+        }
+        f => {
+            vec!(3; 4)
+        }
+        h => println!("a", b), // h comment
+        i => vec!(1, 2), // i comment
+        j => vec!(3; 4), // j comment
+        // k comment
+        k => println!("a", b),
+        // l comment
+        l => vec!(1, 2),
+        // m comment
+        m => vec!(3; 4),
+        // Rewrite splits macro
+        nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn =>
+            println!("a", b),
+        // Rewrite splits macro
+        oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo =>
+            vec!(1, 2),
+        // Macro support fails to recognise this macro as splitable
+        // We push the whole expr to a new line, TODO split this macro as well
+        pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp =>
+            vec!(3; 4),
+        // q, r and s: Rewrite splits match arm
+        qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq =>
+            println!("a", b),
+        rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr =>
+            vec!(1, 2),
+        ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss =>
+            vec!(3; 4),
+        // Funky bracketing styles
+        t => println!{"a", b},
+        u => vec!{1, 2},
+        v => vec!{3; 4},
+        w => println!["a", b],
+        x => vec![1, 2],
+        y => vec![3; 4],
+        // Brackets with comments
+        tc => println!{"a", b}, // comment
+        uc => vec!{1, 2}, // comment
+        vc => vec!{3; 4}, // comment
+        wc => println!["a", b], // comment
+        xc => vec![1, 2], // comment
+        yc => vec![3; 4], // comment
+        yd => looooooooooooooooooooooooooooooooooooooooooooooooooooooooong_func(aaaaaaaaaa,
+                                                                                bbbbbbbbbb,
+                                                                                cccccccccc,
+                                                                                dddddddddd),
     }
 }