provide length_eq and length_ge for StringView

[Yu-zh]

Because the length method for StringView has O(n) time complexity, we provide two auxiliary methods length_eq and length_ge which are fast when the target length is small.

[peter-jerry-ye-code-review]

‼️ This code review is generated by a bot. Please verify the content before trusting it.

Here are three observations from the provided git diff output:

1. Typo in Test Names:

   • In the test cases "stingview length_eq" and "stingview length_ge", the word "stingview" is misspelled. It should be "stringview" to match the naming convention used elsewhere in the codebase. This typo could lead to confusion or issues when searching for or referencing these tests.

2. Potential Logic Issue in length_eq:

   • The length_eq function checks if the length of the view is equal to the given length. However, the logic in the else block (self_len == len && index == self.end) might not correctly handle cases where the view contains surrogate pairs. Specifically, if the loop exits early due to index < self.end being false, but self_len < len is still true, the function might incorrectly return false even if the lengths match. This could lead to incorrect behavior when dealing with strings containing surrogate pairs.

3. Redundant Logic in length_ge:

   • The length_ge function checks if the length of the view is greater than or equal to the given length. However, the loop condition index < self.end && self_len < len ensures that the loop exits as soon as self_len reaches len. This means the else block (self_len >= len) will always be true if the loop exits due to self_len < len being false. This redundancy could be simplified by directly returning true after the loop exits, as the condition self_len >= len is already guaranteed by the loop's exit condition.

These issues should be addressed to ensure the correctness and maintainability of the code.

[coveralls]

Pull Request Test Coverage Report for Build 4726

Details

• 10 of 16 (62.5%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.06%) to 82.832%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
string/view.mbt	10	16	62.5%

Totals
Change from base Build 4725:	-0.06%
Covered Lines:	4815
Relevant Lines:	5813

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💛 - Coveralls