refactor: avoid quadratic behavior in backslash_halve() (#27827)

The original implementation has a worst-case of O(n^2). Every time
rem_backslash() is true, it calculates the length of the rest of the
string, and shift the rest of it to the left; backslash_halve_save()
copies the original string before doing backslash_halve().

The new implementation is O(n). It will find the first character where
rem_backslash() is true (it will do nothing if it's always false), and
shift the characters in-place; backslash_halve_save() avoids copying the
original string before doing backslash_halve().

0 files changed, 0 insertions, 0 deletions