A. Pagaltzis wrote:
Does it mean that basically the assertion is a character/string
property instead of the character/string itself?
No, it is a zero-width assertion. `at(1)` means the position
“between” the 0th and 1th character of the string.
I see thank you
Also, what is the correct way to replace the i-th character in
a Str ?
Ah thank you again, my newbie-ness is extreme.
But doesn't substr modify the string in place?
Is there a side effect-free variant or should I just dup the str ?