Re: string is read-only

[Jean Abou Samra]

> Le 3 août 2022 à 11:49, Taylan Kammer <taylan.kammer@gmail.com> a écrit :
> 
> On 03.08.2022 11:12, Damien Mattei wrote:
>> GNU Guile 3.0.1
>> Copyright (C) 1995-2020 Free Software Foundation, Inc.
>> 
>> Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
>> This program is free software, and you are welcome to redistribute it
>> under certain conditions; type `,show c' for details.
>> 
>> Enter `,help' for help.
>> scheme@(guile-user)> (define str2 "hello")
>> scheme@(guile-user)> (string-set! str2 4 #\a)
>> ice-9/boot-9.scm:1669:16: In procedure raise-exception:
>> string is read-only: "hello"
>> 
>> Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
>> scheme@(guile-user) [1]> ,q
>> scheme@(guile-user)> (string? str2)
>> #t
>> 
>> is it a bug in Guile ? :-O
>> 
>> i can only find reference to deprecated read-only string in old doc:
>> https://www.gnu.org/software/guile/docs/docs-1.6/guile-ref/Read-Only-Strings.html#Read%20Only%20Strings
>>  
>> <https://www.gnu.org/software/guile/docs/docs-1.6/guile-ref/Read-Only-Strings.html#Read%20Only%20Strings>
>> 
>> Regards,
>> 
>> Damien
> 
> String literals are constants, and it's intentional.
> 
> I'm not sure if it's mentioned anywhere in the manual.
> 
> If you want to get a mutable string from a literal, you can use:
> 
>  (define str (string-copy "foobar"))
> 
> -- 
> Taylan

This is standard. See the intro of

https://srfi.schemers.org/srfi-135/

>