Format the last expression-statement as expression (#3631)

[rust.git] / src / expr.rs

diff --git a/src/expr.rs b/src/expr.rs
index 78473803fa969f5e7cb7311b644acec4f120bfa0..d7640bf98caf451340819bcb43fa0d6cf5a34db4 100644 (file)
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -33,7 +33,7 @@
 use crate::utils::{
     colon_spaces, contains_skip, count_newlines, first_line_ends_with, inner_attributes,
     last_line_extendable, last_line_width, mk_sp, outer_attributes, ptr_vec_to_ref_vec,
-    semicolon_for_expr, semicolon_for_stmt, wrap_str,
+    semicolon_for_expr, unicode_str_width, wrap_str,
 };
 use crate::vertical::rewrite_with_alignment;
 use crate::visitor::FmtVisitor;
@@ -568,28 +568,6 @@ fn rewrite_block(
     result
 }
 
-impl Rewrite for ast::Stmt {
-    fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
-        skip_out_of_file_lines_range!(context, self.span());
-
-        let result = match self.node {
-            ast::StmtKind::Local(ref local) => local.rewrite(context, shape),
-            ast::StmtKind::Expr(ref ex) | ast::StmtKind::Semi(ref ex) => {
-                let suffix = if semicolon_for_stmt(context, self) {
-                    ";"
-                } else {
-                    ""
-                };
-
-                let shape = shape.sub_width(suffix.len())?;
-                format_expr(ex, ExprType::Statement, context, shape).map(|s| s + suffix)
-            }
-            ast::StmtKind::Mac(..) | ast::StmtKind::Item(..) => None,
-        };
-        result.and_then(|res| recover_comment_removed(res, self.span(), context))
-    }
-}
-
 // Rewrite condition if the given expression has one.
 pub(crate) fn rewrite_cond(
     context: &RewriteContext<'_>,
@@ -1189,16 +1167,6 @@ pub(crate) fn stmt_is_expr(stmt: &ast::Stmt) -> bool {
     }
 }
 
-pub(crate) fn stmt_is_if(stmt: &ast::Stmt) -> bool {
-    match stmt.node {
-        ast::StmtKind::Expr(ref e) => match e.node {
-            ast::ExprKind::If(..) => true,
-            _ => false,
-        },
-        _ => false,
-    }
-}
-
 pub(crate) fn is_unsafe_block(block: &ast::Block) -> bool {
     if let ast::BlockCheckMode::Unsafe(..) = block.rules {
         true
@@ -1973,7 +1941,9 @@ fn choose_rhs<R: Rewrite>(
     rhs_tactics: RhsTactics,
 ) -> Option<String> {
     match orig_rhs {
-        Some(ref new_str) if !new_str.contains('\n') && new_str.len() <= shape.width => {
+        Some(ref new_str)
+            if !new_str.contains('\n') && unicode_str_width(new_str) <= shape.width =>
+        {
             Some(format!(" {}", new_str))
         }
         _ => {
@@ -2026,6 +1996,15 @@ fn shape_from_rhs_tactic(
     }
 }
 
+/// Returns true if formatting next_line_rhs is better on a new line when compared to the
+/// original's line formatting.
+///
+/// It is considered better if:
+/// 1. the tactic is ForceNextLineWithoutIndent
+/// 2. next_line_rhs doesn't have newlines
+/// 3. the original line has more newlines than next_line_rhs
+/// 4. the original formatting of the first line ends with `(`, `{`, or `[` and next_line_rhs
+///    doesn't
 pub(crate) fn prefer_next_line(
     orig_rhs: &str,
     next_line_rhs: &str,