address review comments

Author: mark-i-m

src/expressions/closure-expr.md

@@ -80,7 +80,7 @@ Attributes on closure parameters follow the same rules and restrictions as
 [_Expression_]: ../expressions.md
 [_BlockExpression_]: block-expr.md
 [_TypeNoBounds_]: ../types.md#type-expressions
-[_Pattern_]: ../patterns.md
+[_PatternNoTopAlt_]: ../patterns.md
 [_Type_]: ../types.md#type-expressions
 [`let` binding]: ../statements.md#let-statements
 [_OuterAttribute_]: ../attributes.md

src/items/functions.md

@@ -378,7 +378,7 @@ fn foo_oof(#[some_inert_attribute] arg: u8) {
 [_BlockExpression_]: ../expressions/block-expr.md
 [_GenericParams_]: generics.md
 [_Lifetime_]: ../trait-bounds.md
-[_Pattern_]: ../patterns.md
+[_PatternNoTopAlt_]: ../patterns.md
 [_Type_]: ../types.md#type-expressions
 [_WhereClause_]: generics.md#where-clauses
 [_OuterAttribute_]: ../attributes.md

src/macros-by-example.md

@@ -28,7 +28,7 @@
 >
 > _MacroFragSpec_ :\
 >       `block` | `expr` | `ident` | `item` | `lifetime` | `literal`\
->    | `meta` | `pat` | `path` | `stmt` | `tt` | `ty` | `vis`
+>    | `meta` | `pat` | `pat2015` | `pat2021` | `path` | `stmt` | `tt` | `ty` | `vis`
 >
 > _MacroRepSep_ :\
 > &nbsp;&nbsp; [_Token_]<sub>_except delimiters and repetition operators_</sub>
@@ -122,7 +122,9 @@ fragment specifiers are:
   * `block`: a [_BlockExpression_]
   * `stmt`: a [_Statement_] without the trailing semicolon (except for item
     statements that require semicolons)
-  * `pat`: a [_Pattern_]
+  * `pat2015`: a [_PatternNoTopAlt_]
+  * `pat2021`: a [_Pattern_]
+  * `pat`: equivalent to either `pat2015` or `pat2021`, depending on edition (see note below).
   * `expr`: an [_Expression_]
   * `ty`: a [_Type_]
   * `ident`: an [IDENTIFIER_OR_KEYWORD]
@@ -133,6 +135,11 @@ fragment specifiers are:
   * `vis`: a possibly empty [_Visibility_] qualifier
   * `literal`: matches `-`<sup>?</sup>[_LiteralExpression_]
 
+> **Edition Differences**: In Editions 2015 and 2018, `pat` fragment-specifiers
+> do not allow top-level or-patterns (i.e. they accept [_PatternNoTopAlt_]). In
+> Edition 2021, this was changed so that top-level or-patterns are accepted by
+> `pat` (i.e. [_Pattern_]).
+
 In the transcriber, metavariables are referred to simply by `$`_name_, since
 the fragment kind is specified in the matcher. Metavariables are replaced with
 the syntax element that matched them. The keyword metavariable `$crate` can be
@@ -489,6 +496,7 @@ For more detail, see the [formal specification].
 [_LiteralExpression_]: expressions/literal-expr.md
 [_MetaListIdents_]: attributes.md#meta-item-attribute-syntax
 [_Pattern_]: patterns.md
+[_PatternNoTopAlt_]: patterns.md
 [_Statement_]: statements.md
 [_TokenTree_]: macros.md#macro-invocation
 [_Token_]: tokens.md

src/patterns.md

@@ -2,12 +2,11 @@
 
 > **<sup>Syntax</sup>**\
 > _Pattern_ :\
-> &nbsp;&nbsp; &nbsp;&nbsp; `|`<sup>?</sup> _PatternNoTopAlt_ `|` _PatternNoTopAlt_
-> &nbsp;&nbsp; | _PatternNoTopAlt_
+> &nbsp;&nbsp; &nbsp;&nbsp; `|`<sup>?</sup> _PatternNoTopAlt_  ( `|` _PatternNoTopAlt_ )<sup>\*</sup>
 >
 > _PatternNoTopAlt_ :\
 > &nbsp;&nbsp; &nbsp;&nbsp; _PatternWithoutRange_\
-> &nbsp;&nbsp; | [_RangePattern_]
+> &nbsp;&nbsp; | [_RangePattern_]\
 > &nbsp;&nbsp; | `(` _Pattern_ `)`
 >
 > _PatternWithoutRange_ :\
@@ -763,12 +762,11 @@ refer to refutable constants or enum variants for enums with multiple variants.
 
 ## Or-patterns
 
-_Or-patterns_ are patterns that match on either of two sub-patterns (e.g. `A |
-B`). They can nest arbitrarily. Syntactically, or-patterns are allowed in any
-of the places where other patterns are allowed (represented by the _Pattern_
-production), with the exceptions of function and closure arguments (represented
-by the _PatternNoTopAlt_ production). Additionally, the macro `:pat` matchers
-only match or-patterns in the 2021+ editions.
+_Or-patterns_ are patterns that match on one of two or more sub-patterns (e.g.
+`A | B | C`). They can nest arbitrarily. Syntactically, or-patterns are allowed
+in any of the places where other patterns are allowed (represented by the
+_Pattern_ production), with the exceptions of `let`-bindings and function and
+closure arguments (represented by the _PatternNoTopAlt_ production).
 
 ### Static semantics
 
@@ -780,8 +778,6 @@ only match or-patterns in the 2021+ editions.
    + the type of any two bindings with the same name in `p` and `q` do not unify
      with respect to types or binding modes.
 
-   [type coercions]: https://doc.rust-lang.org/reference/type-coercions.html
-
    Unification of types is in all instances aforementioned exact and
    implicit [type coercions] do not apply.
 
@@ -838,3 +834,4 @@ only match or-patterns in the 2021+ editions.
 [structs]: items/structs.md
 [tuples]: types/tuple.md
 [scrutinee]: glossary.md#scrutinee
+[type coercions]: type-coercions.md

src/statements.md

@@ -133,5 +133,5 @@ statement are [`cfg`], and [the lint check attributes].
 [_LetStatement_]: #let-statements
 [_MacroInvocationSemi_]: macros.md#macro-invocation
 [_OuterAttribute_]: attributes.md
-[_Pattern_]: patterns.md
+[_PatternNoTopAlt_]: patterns.md
 [_Type_]: types.md