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doc: add docstrings for String.drop and String.dropRight (#7607)

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This PR adds docstrings for `String.drop` and `String.dropRight`.
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David Thrane Christiansen 2025-03-21 06:38:07 +01:00 • committed by GitHub
parent 131b458236
commit 7e1ee70b7c
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src/Init/Data/String/Basic.lean
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@ -1414,9 +1414,29 @@ end Substring
namespace String
/--
Removes the specified number of characters (Unicode code points) from the start of the string.
If `n` is greater than `s.length`, returns `""`.
Examples:
* `"red green blue".drop 4 = "green blue"`
* `"red green blue".drop 10 = "blue"`
* `"red green blue".drop 50 = ""`
-/
@[inline] def drop (s : String) (n : Nat) : String :=
(s.toSubstring.drop n).toString
/--
Removes the specified number of characters (Unicode code points) from the end of the string.
If `n` is greater than `s.length`, returns `""`.
Examples:
* `"red green blue".dropRight 5 = "red green"`
* `"red green blue".dropRight 11 = "red"`
* `"red green blue".dropRight 50 = ""`
-/
@[inline] def dropRight (s : String) (n : Nat) : String :=
(s.toSubstring.dropRight n).toString