This PR fixes#7478 by modifying `number` specifiers from `atLeast size`
to `flexible size` for parsing. This change allows:
- 1 repetition to accept 1 or more characters
- More than 1 repetition to require exactly that many characters
For `year` specifiers, the number of repetitions is always strictly
enforced, requiring exactly the specified amount.
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Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR introduces date and time functionality to the Lean 4 Std.
Breaking Changes:
- `Lean.Data.Rat` is now `Std.Internal.Rat` because it's used by the
DateTime library.
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Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
Co-authored-by: Mac Malone <tydeu@hatpress.net>
