Re: string is read-only

[Maxime Devos]

On 03-08-2022 12:55, Damien Mattei wrote:

but no restrictions with lists in Guile:

scheme@(guile-user)> (define lst '(1 2 3))
scheme@(guile-user)> (set-car! lst 7)
scheme@(guile-user)> lst
(7 2 3)

Non-empty lists are pairs and the second part of the pair is another list -- in Guile, this is effectively implement as having the second part (the cdr) be a kind of pointer.

Pointers need relocation, so lists cannot be put in read-only sections (unless something like RELRO is used), and in Guile pairs do not have 'am I read-only' metadata (unlike strings).

    (My unverified hypothesis on why you aren't seeing an error here.)

Greetings,
Maxime.

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