From ca0b8606882da76ac0a854c7e6d01ec085dae2e0 Mon Sep 17 00:00:00 2001
From: Marcus Klaas <mail@marcusklaas.nl>
Date: Fri, 2 Oct 2015 12:00:28 +0200
Subject: [PATCH] Format repeated element array literals

---
 src/expr.rs          | 38 ++++++++++++++++++++++++++++++++++++--
 tests/source/expr.rs |  5 +++++
 tests/target/expr.rs |  8 ++++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/expr.rs b/src/expr.rs
index b68cbb87580..8d375a8b586 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -183,11 +183,13 @@ fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Opt
             ast::Expr_::ExprIndex(ref expr, ref index) => {
                 rewrite_index(expr, index, context, width, offset)
             }
+            ast::Expr_::ExprRepeat(ref expr, ref repeats) => {
+                rewrite_repeats(expr, repeats, context, width, offset)
+            }
             // We do not format these expressions yet, but they should still
             // satisfy our width restrictions.
             ast::Expr_::ExprInPlace(..) |
-            ast::Expr_::ExprInlineAsm(..) |
-            ast::Expr_::ExprRepeat(..) => {
+            ast::Expr_::ExprInlineAsm(..) => {
                 wrap_str(context.snippet(self.span),
                          context.config.max_width,
                          width,
@@ -197,6 +199,38 @@ fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Opt
     }
 }
 
+fn rewrite_repeats(expr: &ast::Expr,
+                   index: &ast::Expr,
+                   context: &RewriteContext,
+                   width: usize,
+                   offset: Indent)
+                   -> Option<String> {
+    let max_width = try_opt!(width.checked_sub("[; ]".len()));
+
+    binary_search(1,
+                  max_width,
+                  |expr_budget| {
+                      let expr_str = match expr.rewrite(context, expr_budget, offset + "[".len()) {
+                          Some(result) => result,
+                          None => return Err(Ordering::Greater),
+                      };
+
+                      let last_line_width = last_line_width(&expr_str);
+                      let index_budget = match max_width.checked_sub(last_line_width) {
+                          Some(b) => b,
+                          None => return Err(Ordering::Less),
+                      };
+                      let index_indent = offset + last_line_width + "[; ".len();
+
+                      let index_str = match index.rewrite(context, index_budget, index_indent) {
+                          Some(result) => result,
+                          None => return Err(Ordering::Less),
+                      };
+
+                      Ok(format!("[{}; {}]", expr_str, index_str))
+                  })
+}
+
 fn rewrite_index(expr: &ast::Expr,
                  index: &ast::Expr,
                  context: &RewriteContext,
diff --git a/tests/source/expr.rs b/tests/source/expr.rs
index 16b9047dcf1..45f688693f6 100644
--- a/tests/source/expr.rs
+++ b/tests/source/expr.rs
@@ -202,3 +202,8 @@ fn indices() {
     let x = (aaaaaaaaaaaaaaaaaaaaaaaaaaaa+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb+cccccccccccccccc) [ x + y + z ];
     let y = (aaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb + cccccccccccccccc)[ xxxxx + yyyyy + zzzzz ];
 }
+
+fn repeats() {
+    let x = [aaaaaaaaaaaaaaaaaaaaaaaaaaaa+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb+cccccccccccccccc; x + y + z ];
+    let y = [aaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb + cccccccccccccccc; xxxxx + yyyyy + zzzzz ];
+}
diff --git a/tests/target/expr.rs b/tests/target/expr.rs
index ab25d489c1b..6fe472c114e 100644
--- a/tests/target/expr.rs
+++ b/tests/target/expr.rs
@@ -216,3 +216,11 @@ fn indices() {
     let y = (aaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb +
              cccccccccccccccc)[xxxxx + yyyyy + zzzzz];
 }
+
+fn repeats() {
+    let x = [aaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb + cccccccccccccccc; x +
+                                                                                                y +
+                                                                                                z];
+    let y = [aaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb +
+             cccccccccccccccc; xxxxx + yyyyy + zzzzz];
+}
-- 
2.44.0