Coalesce trailing comma options

Author: nrc

src/config.rs

@@ -104,6 +104,7 @@ configuration_option_enum! { TypeDensity:
     Wide,
 }
 
+
 impl Density {
     pub fn to_list_tactic(self) -> ListTactic {
         match self {
@@ -348,6 +349,8 @@ create_config! {
     control_brace_style: ControlBraceStyle, ControlBraceStyle::AlwaysSameLine,
         "Brace style for control flow constructs";
     impl_empty_single_line: bool, true, "Put empty-body implementations on a single line";
+    trailing_comma: SeparatorTactic, SeparatorTactic::Vertical,
+        "How to handle trailing commas for lists";
     fn_empty_single_line: bool, true, "Put empty-body functions on a single line";
     fn_single_line: bool, false, "Put single-expression functions on a single line";
     fn_return_indent: ReturnIndent, ReturnIndent::WithArgs,
@@ -366,16 +369,10 @@ create_config! {
     where_layout: ListTactic, ListTactic::Vertical, "Element layout inside a where clause";
     where_pred_indent: BlockIndentStyle, BlockIndentStyle::Visual,
         "Indentation style of a where predicate";
-    where_trailing_comma: bool, false, "Put a trailing comma on where clauses";
     generics_indent: BlockIndentStyle, BlockIndentStyle::Visual, "Indentation of generics";
-    struct_trailing_comma: SeparatorTactic, SeparatorTactic::Vertical,
-        "If there is a trailing comma on structs";
-    struct_lit_trailing_comma: SeparatorTactic, SeparatorTactic::Vertical,
-        "If there is a trailing comma on literal structs";
     struct_lit_style: StructLitStyle, StructLitStyle::Block, "Style of struct definition";
     struct_lit_multiline_style: MultilineStyle, MultilineStyle::PreferSingle,
         "Multiline style on literal structs";
-    enum_trailing_comma: bool, true, "Put a trailing comma on enum declarations";
     report_todo: ReportTactic, ReportTactic::Never,
         "Report all, none or unnumbered occurrences of TODO in source file comments";
     report_fixme: ReportTactic, ReportTactic::Never,
@@ -396,7 +393,6 @@ create_config! {
     wrap_match_arms: bool, true, "Wrap multiline match arms in blocks";
     match_block_trailing_comma: bool, false,
         "Put a trailing comma after a block based match arm (non-block arms are not affected)";
-    match_wildcard_trailing_comma: bool, true, "Put a trailing comma after a wildcard arm";
     closure_block_indent_threshold: isize, 5, "How many lines a closure must have before it is \
                                                block indented. -1 means never use block indent.";
     space_before_type_annotation: bool, false,

src/expr.rs

@@ -1150,12 +1150,6 @@ fn arm_end_pos(arm: &ast::Arm) -> BytePos {
 }
 
 fn arm_comma(config: &Config, arm: &ast::Arm, body: &ast::Expr) -> &'static str {
-    if !config.match_wildcard_trailing_comma {
-        if arm.pats.len() == 1 && arm.pats[0].node == ast::PatKind::Wild && arm.guard.is_none() {
-            return "";
-        }
-    }
-
     if config.match_block_trailing_comma {
         ","
     } else if let ast::ExprKind::Block(ref block) = body.node {
@@ -1759,7 +1753,7 @@ fn rewrite_struct_lit<'a>(context: &RewriteContext,
         trailing_separator: if base.is_some() {
             SeparatorTactic::Never
         } else {
-            context.config.struct_lit_trailing_comma
+            context.config.trailing_comma
         },
         shape: nested_shape,
         ends_with_newline: ends_with_newline,

src/items.rs

@@ -434,7 +434,7 @@ impl<'a> FmtVisitor<'a> {
         let fmt = ListFormatting {
             tactic: DefinitiveListTactic::Vertical,
             separator: ",",
-            trailing_separator: SeparatorTactic::from_bool(self.config.enum_trailing_comma),
+            trailing_separator: self.config.trailing_comma,
             shape: Shape::legacy(budget, self.block_indent),
             ends_with_newline: true,
             config: self.config,
@@ -526,7 +526,6 @@ pub fn format_impl(context: &RewriteContext, item: &ast::Item, offset: Indent) -
                                                                            offset.block_only()),
                                                              context.config.where_density,
                                                              "{",
-                                                             true,
                                                              None));
 
         if try_opt!(is_impl_single_line(context, &items, &result, &where_clause_str, &item)) {
@@ -795,7 +794,6 @@ pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent)
                                                                            offset.block_only()),
                                                              where_density,
                                                              "{",
-                                                             has_body,
                                                              None));
         // If the where clause cannot fit on the same line,
         // put the where clause on a new line
@@ -952,7 +950,7 @@ fn format_struct_struct(context: &RewriteContext,
     let fmt = ListFormatting {
         tactic: tactic,
         separator: ",",
-        trailing_separator: context.config.struct_trailing_comma,
+        trailing_separator: context.config.trailing_comma,
         shape: Shape::legacy(budget, item_indent),
         ends_with_newline: true,
         config: context.config,
@@ -1010,7 +1008,6 @@ fn format_tuple_struct(context: &RewriteContext,
                                           Shape::legacy(where_budget, offset.block_only()),
                                           Density::Compressed,
                                           ";",
-                                          false,
                                           None))
         }
         None => "".to_owned(),
@@ -1103,7 +1100,6 @@ pub fn rewrite_type_alias(context: &RewriteContext,
                                                          Shape::legacy(where_budget, indent),
                                                          context.config.where_density,
                                                          "=",
-                                                         false,
                                                          Some(span.hi)));
     result.push_str(&where_clause_str);
     result.push_str(" = ");
@@ -1645,7 +1641,6 @@ fn rewrite_fn_base(context: &RewriteContext,
                                                          Shape::legacy(where_budget, indent),
                                                          where_density,
                                                          "{",
-                                                         has_body,
                                                          Some(span.hi)));
 
     if last_line_width(&result) + where_clause_str.len() > context.config.max_width &&
@@ -1929,7 +1924,6 @@ fn rewrite_where_clause(context: &RewriteContext,
                         shape: Shape,
                         density: Density,
                         terminator: &str,
-                        allow_trailing_comma: bool,
                         span_end: Option<BytePos>)
                         -> Option<String> {
     if where_clause.predicates.is_empty() {
@@ -1969,12 +1963,17 @@ fn rewrite_where_clause(context: &RewriteContext,
     // FIXME: we don't need to collect here if the where_layout isn't
     // HorizontalVertical.
     let tactic = definitive_tactic(&item_vec, context.config.where_layout, budget);
-    let use_trailing_comma = allow_trailing_comma && context.config.where_trailing_comma;
+
+    let mut comma_tactic = context.config.trailing_comma;
+    // Kind of a hack because we don't usually have trailing commas in where clauses.
+    if comma_tactic == SeparatorTactic::Vertical {
+        comma_tactic = SeparatorTactic::Never;
+    }
 
     let fmt = ListFormatting {
         tactic: tactic,
         separator: ",",
-        trailing_separator: SeparatorTactic::from_bool(use_trailing_comma),
+        trailing_separator: comma_tactic,
         shape: Shape::legacy(budget, offset),
         ends_with_newline: true,
         config: context.config,
@@ -2034,7 +2033,6 @@ fn format_generics(context: &RewriteContext,
                                                                            offset.block_only()),
                                                              Density::Tall,
                                                              terminator,
-                                                             true,
                                                              Some(span.hi)));
         result.push_str(&where_clause_str);
         if !force_same_line_brace &&

tests/config/small_tabs.toml

@@ -12,12 +12,9 @@ where_density = "Tall"
 where_indent = "Tabbed"
 where_layout = "Vertical"
 where_pred_indent = "Visual"
-where_trailing_comma = false
 generics_indent = "Visual"
-struct_trailing_comma = "Vertical"
-struct_lit_trailing_comma = "Vertical"
+trailing_comma = "Vertical"
 struct_lit_style = "Block"
-enum_trailing_comma = true
 report_todo = "Always"
 report_fixme = "Never"
 reorder_imports = false