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Fix grammar rules pertaining to obsolete range patterns #2259

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Fix grammar rules pertaining to obsolete range patterns #2259

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16 changes: 8 additions & 8 deletions src/patterns.md
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@fmease fmease May 5, 2026 •
edited by rustbot
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I'm fine with reverting the Range → ModernRange renaming.

Advantage of the renaming: It prevents confusion that could lead to people repeatedly opening issues and PRs trying to move ObsoleteRangePattern back into RangePattern believing it to be a mistake.

Disadvantage of the renaming: It painfully highlights the fact that there are modern and obsolete range patterns; the latter are no longer hidden at the bottom of RangePattern's definition.

View changes since the review

Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,10 @@ r[patterns.syntax]
Pattern -> `|`? PatternNoTopAlt ( `|` PatternNoTopAlt )*

PatternNoTopAlt ->
PatternWithoutRange
| RangePattern
PatternWithoutModernRange
| ModernRangePattern

PatternWithoutRange ->
PatternWithoutModernRange ->
LiteralPattern
| IdentifierPattern
| WildcardPattern
Expand All @@ -22,8 +22,11 @@ PatternWithoutRange ->
| SlicePattern
| PathPattern
| MacroInvocation
| ObsoleteRangePattern[^obsolete-range-edition]
```

[^obsolete-range-edition]: The [ObsoleteRangePattern] syntax is semantically invalid in the 2021 edition and beyond.

r[patterns.intro]
Patterns are used to match values against structures and to, optionally, bind variables to values inside these structures. They are also used in variable declarations and parameters for functions and closures.

Expand Down Expand Up @@ -464,13 +467,12 @@ r[patterns.range]

r[patterns.range.syntax]
```grammar,patterns
RangePattern ->
ModernRangePattern ->
RangeExclusivePattern
| RangeInclusivePattern
| RangeFromPattern
| RangeToExclusivePattern
| RangeToInclusivePattern
| ObsoleteRangePattern[^obsolete-range-edition]

RangeExclusivePattern ->
RangePatternBound `..` RangePatternBound
Expand All @@ -495,8 +497,6 @@ RangePatternBound ->
| PathExpression
```

[^obsolete-range-edition]: The [ObsoleteRangePattern] syntax has been removed in the 2021 edition.

r[patterns.range.intro]
*Range patterns* match scalar values within the range defined by their bounds. They comprise a *sigil* (`..` or `..=`) and a bound on one or both sides.

Expand Down Expand Up @@ -659,7 +659,7 @@ r[patterns.ref]

r[patterns.ref.syntax]
```grammar,patterns
ReferencePattern -> (`&`|`&&`) `mut`? PatternWithoutRange
ReferencePattern -> (`&`|`&&`) `mut`? PatternWithoutModernRange
```

r[patterns.ref.intro]
Expand Down
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