Let’s say i have a string “abcde”. I want to change the 3th character from ‘c’ to ‘x’. Can i use a library function ?

Check out the String.mapi function, it can do the job.

If i’m correct strings are immutable so the whole string is copied. Time n. I had thought of converting a string to an array of bytes. Changing one byte in the array and converting the array of bytes to a string. The conversion will also take a time n. And i have no clue how to do the conversion. …

I think you need to rethink this a bit, because there’s two possible things you want: You want to change the second character You want to change the second byte With ASCII the former and the latter is the same, but in the presence of Unicode, what would you expect to change in the string " :fr: …

Can’t do it in Java, either. Look: maybe OCaml isn’t right for you. Maybe functional languages aren’t your cup of tea.

I wouldn’t say that. Alain seems to be eager to learn and having fun (look at the lazy Fibonacci thread). It takes time to change from an imperative/OOP mindset to an FP mindset.

Strings in OCaml are immutable. Though I’ve never used Dlang, I would guess that because it bills itself as a C alternative that strings are mutable there. @yawaramin mentioned you can use Bytes.{of_string|to_string} to convert to and from strings, but as you note both of these operations are O(n),…

[ Sidenote, dlang strings are immutable, but can very easily be converted to another datatype ] I have a theoretical/philosophical question. Would it be possible to create a mutable string “type” with log(n) character lookup time for modification, even if it’s unwise/unusefull. How would one do th…

[image] zbaylin: but as you note both of these operations are O(n), Zach, I believe this is incorrect. I checked the source and the safe conversion operation seems to be doing a blit (copy) and then a primitive operation to recast a string as bytes. [image] devosalain: [ Sidenote, dlang …

I’m slightly confused. Looking at the source of the operations , they both perform a copy, which is at least O(n), no? Diving further into the source, copy calls unsafe_blit, which is the C function caml_blit_bytes . This is effectively an OCaml wrapper on top of memmove. memmove has to iterate over e…

Change middle character of a string

Learning

yawaramin June 2, 2022, 3:34am 4

You will find all the answers in the String and Bytes module documentation.

Topic		Replies	Views
String.set conversion to OCaml 5 Learning	2	475	December 11, 2023
Should I use bytes or string? Learning	2	929	May 14, 2022
Could we move string and bytes to sliced types? Ecosystem language	27	930	December 31, 2024
How to replace strings with bytes in old C stub code Learning	4	892	July 13, 2018
Syntaxic sugar: String.set -> Bytes.set? Learning evolution	17	1399	August 13, 2022

Change middle character of a string

Related topics