Auto merge of #29486 - petrochenkov:multiwild, r=Manishearth

bors · bors · commit 6d43fef3aaf6 · 2015-11-01T13:36:49.000Z
Motivation:
- It is not actually a pattern
- It is not actually needed, except for...

Drawback:
- Slice patterns like `[a, _.., b]` are pretty-printed as `[a, .., b]`. Great loss :(

plugin-[breaking-change], as always
diff --git a/src/librustc/middle/cfg/construct.rs b/src/librustc/middle/cfg/construct.rs
@@ -104,7 +104,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
             hir::PatQPath(..) |
             hir::PatLit(..) |
             hir::PatRange(..) |
-            hir::PatWild(_) => {
+            hir::PatWild => {
                 self.add_ast_node(pat.id, &[pred])
             }
 
diff --git a/src/librustc/middle/check_const.rs b/src/librustc/middle/check_const.rs
@@ -176,7 +176,7 @@ impl<'a, 'tcx> CheckCrateVisitor<'a, 'tcx> {
         if mode == Mode::ConstFn {
             for arg in &fd.inputs {
                 match arg.pat.node {
-                    hir::PatWild(_) => {}
+                    hir::PatWild => {}
                     hir::PatIdent(hir::BindByValue(hir::MutImmutable), _, None) => {}
                     _ => {
                         span_err!(self.tcx.sess, arg.pat.span, E0022,
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs
@@ -47,7 +47,7 @@ use util::nodemap::FnvHashMap;
 
 pub const DUMMY_WILD_PAT: &'static Pat = &Pat {
     id: DUMMY_NODE_ID,
-    node: hir::PatWild(hir::PatWildSingle),
+    node: hir::PatWild,
     span: DUMMY_SP
 };
 
@@ -521,7 +521,7 @@ fn construct_witness<'a,'tcx>(cx: &MatchCheckCtxt<'a,'tcx>, ctor: &Constructor,
             if let VariantKind::Struct = v.kind() {
                 let field_pats: Vec<_> = v.fields.iter()
                     .zip(pats)
-                    .filter(|&(_, ref pat)| pat.node != hir::PatWild(hir::PatWildSingle))
+                    .filter(|&(_, ref pat)| pat.node != hir::PatWild)
                     .map(|(field, pat)| Spanned {
                         span: DUMMY_SP,
                         node: hir::FieldPat {
@@ -553,7 +553,7 @@ fn construct_witness<'a,'tcx>(cx: &MatchCheckCtxt<'a,'tcx>, ctor: &Constructor,
                     },
                     _ => unreachable!()
                 },
-                ty::TyStr => hir::PatWild(hir::PatWildSingle),
+                ty::TyStr => hir::PatWild,
 
                 _ => {
                     assert_eq!(pats_len, 1);
@@ -570,7 +570,7 @@ fn construct_witness<'a,'tcx>(cx: &MatchCheckCtxt<'a,'tcx>, ctor: &Constructor,
         _ => {
             match *ctor {
                 ConstantValue(ref v) => hir::PatLit(const_val_to_expr(v)),
-                _ => hir::PatWild(hir::PatWildSingle),
+                _ => hir::PatWild,
             }
         }
     };
@@ -799,7 +799,7 @@ fn pat_constructors(cx: &MatchCheckCtxt, p: &Pat,
             },
         hir::PatBox(_) | hir::PatTup(_) | hir::PatRegion(..) =>
             vec!(Single),
-        hir::PatWild(_) =>
+        hir::PatWild =>
             vec!(),
     }
 }
@@ -862,7 +862,7 @@ pub fn specialize<'a>(cx: &MatchCheckCtxt, r: &[&'a Pat],
         id: pat_id, ref node, span: pat_span
     } = raw_pat(r[col]);
     let head: Option<Vec<&Pat>> = match *node {
-        hir::PatWild(_) =>
+        hir::PatWild =>
             Some(vec![DUMMY_WILD_PAT; arity]),
 
         hir::PatIdent(_, _, _) => {
diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
@@ -142,7 +142,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
             _ => self.tcx.sess.span_bug(lhs.span, "non-ADT in struct pattern")
         };
         for pat in pats {
-            if let hir::PatWild(hir::PatWildSingle) = pat.node.pat.node {
+            if let hir::PatWild = pat.node.pat.node {
                 continue;
             }
             self.insert_def_id(variant.field_named(pat.node.name).did);
diff --git a/src/librustc/middle/expr_use_visitor.rs b/src/librustc/middle/expr_use_visitor.rs
@@ -1141,7 +1141,7 @@ impl<'d,'t,'a,'tcx> ExprUseVisitor<'d,'t,'a,'tcx> {
                     // will visit the substructure recursively.
                 }
 
-                hir::PatWild(_) | hir::PatTup(..) | hir::PatBox(..) |
+                hir::PatWild | hir::PatTup(..) | hir::PatBox(..) |
                 hir::PatRegion(..) | hir::PatLit(..) | hir::PatRange(..) |
                 hir::PatVec(..) => {
                     // Similarly, each of these cases does not
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
@@ -1211,7 +1211,7 @@ impl<'t, 'a,'tcx> MemCategorizationContext<'t, 'a, 'tcx> {
         };
 
         match pat.node {
-          hir::PatWild(_) => {
+          hir::PatWild => {
             // _
           }
 
diff --git a/src/librustc/middle/pat_util.rs b/src/librustc/middle/pat_util.rs
@@ -101,7 +101,7 @@ pub fn pat_is_binding(dm: &DefMap, pat: &hir::Pat) -> bool {
 pub fn pat_is_binding_or_wild(dm: &DefMap, pat: &hir::Pat) -> bool {
     match pat.node {
         hir::PatIdent(..) => pat_is_binding(dm, pat),
-        hir::PatWild(_) => true,
+        hir::PatWild => true,
         _ => false
     }
 }
diff --git a/src/librustc/middle/stability.rs b/src/librustc/middle/stability.rs
@@ -541,13 +541,9 @@ pub fn check_pat(tcx: &ty::ctxt, pat: &hir::Pat,
     };
     match pat.node {
         // Foo(a, b, c)
+        // A Variant(..) pattern `hir::PatEnum(_, None)` doesn't have to be recursed into.
         hir::PatEnum(_, Some(ref pat_fields)) => {
             for (field, struct_field) in pat_fields.iter().zip(&v.fields) {
-                // a .. pattern is fine, but anything positional is
-                // not.
-                if let hir::PatWild(hir::PatWildMulti) = field.node {
-                    continue
-                }
                 maybe_do_stability_check(tcx, struct_field.did, field.span, cb)
             }
         }
diff --git a/src/librustc_front/fold.rs b/src/librustc_front/fold.rs
@@ -1010,7 +1010,7 @@ pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
         Pat {
             id: folder.new_id(id),
             node: match node {
-                PatWild(k) => PatWild(k),
+                PatWild => PatWild,
                 PatIdent(binding_mode, pth1, sub) => {
                     PatIdent(binding_mode,
                              Spanned {
diff --git a/src/librustc_front/hir.rs b/src/librustc_front/hir.rs
@@ -24,7 +24,6 @@ pub use self::Item_::*;
 pub use self::Mutability::*;
 pub use self::Pat_::*;
 pub use self::PathListItem_::*;
-pub use self::PatWildKind::*;
 pub use self::PrimTy::*;
 pub use self::Stmt_::*;
 pub use self::StructFieldKind::*;
@@ -393,19 +392,10 @@ pub enum BindingMode {
     BindByValue(Mutability),
 }
 
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
-pub enum PatWildKind {
-    /// Represents the wildcard pattern `_`
-    PatWildSingle,
-
-    /// Represents the wildcard pattern `..`
-    PatWildMulti,
-}
-
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Pat_ {
-    /// Represents a wildcard pattern (either `_` or `..`)
-    PatWild(PatWildKind),
+    /// Represents a wildcard pattern (`_`)
+    PatWild,
 
     /// A PatIdent may either be a new bound variable,
     /// or a nullary enum (in which case the third field
diff --git a/src/librustc_front/lowering.rs b/src/librustc_front/lowering.rs
@@ -818,7 +818,7 @@ pub fn lower_pat(_lctx: &LoweringContext, p: &Pat) -> P<hir::Pat> {
     P(hir::Pat {
         id: p.id,
         node: match p.node {
-            PatWild(k) => hir::PatWild(lower_pat_wild_kind(_lctx, k)),
+            PatWild => hir::PatWild,
             PatIdent(ref binding_mode, pth1, ref sub) => {
                 hir::PatIdent(lower_binding_mode(_lctx, binding_mode),
                               pth1,
@@ -1482,13 +1482,6 @@ pub fn lower_block_check_mode(_lctx: &LoweringContext, b: &BlockCheckMode) -> hi
     }
 }
 
-pub fn lower_pat_wild_kind(_lctx: &LoweringContext, p: PatWildKind) -> hir::PatWildKind {
-    match p {
-        PatWildSingle => hir::PatWildSingle,
-        PatWildMulti => hir::PatWildMulti,
-    }
-}
-
 pub fn lower_binding_mode(_lctx: &LoweringContext, b: &BindingMode) -> hir::BindingMode {
     match *b {
         BindByRef(m) => hir::BindByRef(lower_mutability(_lctx, m)),
@@ -1670,7 +1663,7 @@ fn pat_ident_binding_mode(lctx: &LoweringContext,
 }
 
 fn pat_wild(lctx: &LoweringContext, span: Span) -> P<hir::Pat> {
-    pat(lctx, span, hir::PatWild(hir::PatWildSingle))
+    pat(lctx, span, hir::PatWild)
 }
 
 fn pat(lctx: &LoweringContext, span: Span, pat: hir::Pat_) -> P<hir::Pat> {
diff --git a/src/librustc_front/print/pprust.rs b/src/librustc_front/print/pprust.rs
@@ -1719,8 +1719,7 @@ impl<'a> State<'a> {
         /* Pat isn't normalized, but the beauty of it
          is that it doesn't matter */
         match pat.node {
-            hir::PatWild(hir::PatWildSingle) => try!(word(&mut self.s, "_")),
-            hir::PatWild(hir::PatWildMulti) => try!(word(&mut self.s, "..")),
+            hir::PatWild => try!(word(&mut self.s, "_")),
             hir::PatIdent(binding_mode, ref path1, ref sub) => {
                 match binding_mode {
                     hir::BindByRef(mutbl) => {
@@ -1815,13 +1814,10 @@ impl<'a> State<'a> {
                     if !before.is_empty() {
                         try!(self.word_space(","));
                     }
-                    try!(self.print_pat(&**p));
-                    match **p {
-                        hir::Pat { node: hir::PatWild(hir::PatWildMulti), .. } => {
-                            // this case is handled by print_pat
-                        }
-                        _ => try!(word(&mut self.s, "..")),
+                    if p.node != hir::PatWild {
+                        try!(self.print_pat(&**p));
                     }
+                    try!(word(&mut self.s, ".."));
                     if !after.is_empty() {
                         try!(self.word_space(","));
                     }
diff --git a/src/librustc_front/util.rs b/src/librustc_front/util.rs
@@ -44,7 +44,7 @@ pub fn walk_pat<F>(pat: &Pat, mut it: F) -> bool
                 slice.iter().all(|p| walk_pat_(&**p, it)) &&
                 after.iter().all(|p| walk_pat_(&**p, it))
             }
-            PatWild(_) |
+            PatWild |
             PatLit(_) |
             PatRange(_, _) |
             PatIdent(_, _, _) |
diff --git a/src/librustc_front/visit.rs b/src/librustc_front/visit.rs
@@ -466,7 +466,7 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
             visitor.visit_expr(lower_bound);
             visitor.visit_expr(upper_bound)
         }
-        PatWild(_) => (),
+        PatWild => (),
         PatVec(ref prepatterns, ref slice_pattern, ref postpatterns) => {
             walk_list!(visitor, visit_pat, prepatterns);
             walk_list!(visitor, visit_pat, slice_pattern);
diff --git a/src/librustc_mir/tcx/pattern.rs b/src/librustc_mir/tcx/pattern.rs
@@ -139,7 +139,7 @@ impl<'tcx> Mirror<'tcx> for PatNode<'tcx> {
 
     fn make_mirror<'a>(self, cx: &mut Cx<'a, 'tcx>) -> Pattern<'tcx> {
         let kind = match self.pat.node {
-            hir::PatWild(..) => PatternKind::Wild,
+            hir::PatWild => PatternKind::Wild,
 
             hir::PatLit(ref value) => {
                 let value = const_eval::eval_const_expr(cx.tcx, value);
diff --git a/src/librustc_privacy/lib.rs b/src/librustc_privacy/lib.rs
@@ -962,7 +962,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for PrivacyVisitor<'a, 'tcx> {
                 match self.tcx.pat_ty(pattern).sty {
                     ty::TyStruct(def, _) => {
                         for (i, field) in fields.iter().enumerate() {
-                            if let hir::PatWild(..) = field.node {
+                            if let hir::PatWild = field.node {
                                 continue
                             }
                             self.check_field(field.span,
diff --git a/src/librustc_trans/trans/_match.rs b/src/librustc_trans/trans/_match.rs
@@ -866,7 +866,7 @@ fn pick_column_to_specialize(def_map: &DefMap, m: &[Match]) -> Option<usize> {
 
     let column_contains_any_nonwild_patterns = |&col: &usize| -> bool {
         m.iter().any(|row| match row.pats[col].node {
-            hir::PatWild(_) => false,
+            hir::PatWild => false,
             _ => true
         })
     };
@@ -1629,7 +1629,7 @@ fn trans_match_inner<'blk, 'tcx>(scope_cx: Block<'blk, 'tcx>,
     // to the default arm.
     let has_default = arms.last().map_or(false, |arm| {
         arm.pats.len() == 1
-        && arm.pats.last().unwrap().node == hir::PatWild(hir::PatWildSingle)
+        && arm.pats.last().unwrap().node == hir::PatWild
     });
 
     compile_submatch(bcx, &matches[..], &[discr_datum.match_input()], &chk, has_default);
@@ -1948,7 +1948,7 @@ pub fn bind_irrefutable_pat<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                         cleanup_scope)
                 });
         }
-        hir::PatQPath(..) | hir::PatWild(_) | hir::PatLit(_) |
+        hir::PatQPath(..) | hir::PatWild | hir::PatLit(_) |
         hir::PatRange(_, _) => ()
     }
     return bcx;
diff --git a/src/librustc_trans/trans/debuginfo/create_scope_map.rs b/src/librustc_trans/trans/debuginfo/create_scope_map.rs
@@ -235,7 +235,7 @@ fn walk_pattern(cx: &CrateContext,
             }
         }
 
-        hir::PatWild(_) => {
+        hir::PatWild => {
             scope_map.insert(pat.id, scope_stack.last().unwrap().scope_metadata);
         }
 
@@ -485,4 +485,4 @@ fn walk_expr(cx: &CrateContext,
             }
         }
     }
-}
+}
diff --git a/src/librustc_typeck/check/_match.rs b/src/librustc_typeck/check/_match.rs
@@ -44,7 +44,7 @@ pub fn check_pat<'a, 'tcx>(pcx: &pat_ctxt<'a, 'tcx>,
            expected);
 
     match pat.node {
-        hir::PatWild(_) => {
+        hir::PatWild => {
             fcx.write_ty(pat.id, expected);
         }
         hir::PatLit(ref lt) => {
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
@@ -2218,7 +2218,7 @@ fn compute_type_scheme_of_foreign_fn_decl<'a, 'tcx>(
     for i in &decl.inputs {
         match (*i).pat.node {
             hir::PatIdent(_, _, _) => (),
-            hir::PatWild(hir::PatWildSingle) => (),
+            hir::PatWild => (),
             _ => {
                 span_err!(ccx.tcx.sess, (*i).pat.span, E0130,
                           "patterns aren't allowed in foreign function declarations");
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
@@ -2528,8 +2528,7 @@ fn name_from_pat(p: &hir::Pat) -> String {
     debug!("Trying to get a name from pattern: {:?}", p);
 
     match p.node {
-        PatWild(PatWildSingle) => "_".to_string(),
-        PatWild(PatWildMulti) => "..".to_string(),
+        PatWild => "_".to_string(),
         PatIdent(_, ref p, _) => p.node.to_string(),
         PatEnum(ref p, _) => path_to_string(p),
         PatQPath(..) => panic!("tried to get argument name from PatQPath, \
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
@@ -31,7 +31,6 @@ pub use self::MetaItem_::*;
 pub use self::Mutability::*;
 pub use self::Pat_::*;
 pub use self::PathListItem_::*;
-pub use self::PatWildKind::*;
 pub use self::PrimTy::*;
 pub use self::Sign::*;
 pub use self::Stmt_::*;
@@ -569,19 +568,10 @@ pub enum BindingMode {
     BindByValue(Mutability),
 }
 
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
-pub enum PatWildKind {
-    /// Represents the wildcard pattern `_`
-    PatWildSingle,
-
-    /// Represents the wildcard pattern `..`
-    PatWildMulti,
-}
-
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Pat_ {
-    /// Represents a wildcard pattern (either `_` or `..`)
-    PatWild(PatWildKind),
+    /// Represents a wildcard pattern (`_`)
+    PatWild,
 
     /// A PatIdent may either be a new bound variable,
     /// or a nullary enum (in which case the third field
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
@@ -356,7 +356,7 @@ impl DummyResult {
     pub fn raw_pat(sp: Span) -> ast::Pat {
         ast::Pat {
             id: ast::DUMMY_NODE_ID,
-            node: ast::PatWild(ast::PatWildSingle),
+            node: ast::PatWild,
             span: sp,
         }
     }
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
@@ -801,7 +801,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         P(ast::Pat { id: ast::DUMMY_NODE_ID, node: pat, span: span })
     }
     fn pat_wild(&self, span: Span) -> P<ast::Pat> {
-        self.pat(span, ast::PatWild(ast::PatWildSingle))
+        self.pat(span, ast::PatWild)
     }
     fn pat_lit(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Pat> {
         self.pat(span, ast::PatLit(expr))
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
@@ -1125,7 +1125,7 @@ pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
     p.map(|Pat {id, node, span}| Pat {
         id: folder.new_id(id),
         node: match node {
-            PatWild(k) => PatWild(k),
+            PatWild => PatWild,
             PatIdent(binding_mode, pth1, sub) => {
                 PatIdent(binding_mode,
                         Spanned{span: folder.new_span(pth1.span),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
diff --git a/src/test/run-make/graphviz-flowgraph/f07.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f07.dot-expected.dot

Original file line number	Diff line number	Diff line change
`@@ -104,7 +104,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {`
`104`	`104`	`hir::PatQPath(..) \|`
`105`	`105`	`hir::PatLit(..) \|`
`106`	`106`	`hir::PatRange(..) \|`
`107`		`- hir::PatWild(_) => {`
	`107`	`+ hir::PatWild => {`
`108`	`108`	`self.add_ast_node(pat.id, &[pred])`
`109`	`109`	`}`
`110`	`110`
Original file line number	Diff line number	Diff line change
`@@ -142,7 +142,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {`
`142`	`142`	`_ => self.tcx.sess.span_bug(lhs.span, "non-ADT in struct pattern")`
`143`	`143`	`};`
`144`	`144`	`for pat in pats {`
`145`		`- if let hir::PatWild(hir::PatWildSingle) = pat.node.pat.node {`
	`145`	`+ if let hir::PatWild = pat.node.pat.node {`
`146`	`146`	`continue;`
`147`	`147`	`}`
`148`	`148`	`self.insert_def_id(variant.field_named(pat.node.name).did);`
Original file line number	Diff line number	Diff line change
`@@ -1141,7 +1141,7 @@ impl<'d,'t,'a,'tcx> ExprUseVisitor<'d,'t,'a,'tcx> {`
`1141`	`1141`	`// will visit the substructure recursively.`
`1142`	`1142`	`}`
`1143`	`1143`
`1144`		`- hir::PatWild(_) \| hir::PatTup(..) \| hir::PatBox(..) \|`
	`1144`	`+ hir::PatWild \| hir::PatTup(..) \| hir::PatBox(..) \|`
`1145`	`1145`	`hir::PatRegion(..) \| hir::PatLit(..) \| hir::PatRange(..) \|`
`1146`	`1146`	`hir::PatVec(..) => {`
`1147`	`1147`	`// Similarly, each of these cases does not`
Original file line number	Diff line number	Diff line change
`@@ -1211,7 +1211,7 @@ impl<'t, 'a,'tcx> MemCategorizationContext<'t, 'a, 'tcx> {`
`1211`	`1211`	`};`
`1212`	`1212`
`1213`	`1213`	`match pat.node {`
`1214`		`- hir::PatWild(_) => {`
	`1214`	`+ hir::PatWild => {`
`1215`	`1215`	`// _`
`1216`	`1216`	`}`
`1217`	`1217`
Original file line number	Diff line number	Diff line change
`@@ -101,7 +101,7 @@ pub fn pat_is_binding(dm: &DefMap, pat: &hir::Pat) -> bool {`
`101`	`101`	`pub fn pat_is_binding_or_wild(dm: &DefMap, pat: &hir::Pat) -> bool {`
`102`	`102`	`match pat.node {`
`103`	`103`	`hir::PatIdent(..) => pat_is_binding(dm, pat),`
`104`		`- hir::PatWild(_) => true,`
	`104`	`+ hir::PatWild => true,`
`105`	`105`	`_ => false`
`106`	`106`	`}`
`107`	`107`	`}`