> Le 3 août 2022 à 12:30, Taylan Kammer <taylan.kam...@gmail.com> a écrit : > > On 03.08.2022 11:50, Jean Abou Samra wrote: >> >> >>>> Le 3 août 2022 à 11:49, Taylan Kammer <taylan.kam...@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/ <https://srfi.schemers.org/srfi-135/> >> >>> > > This SRFI defines a new data type, which is not really relevant here. > > As far as I know, Guile doesn't support it yet anyway.
I just wanted to point to the intro, which summarizes the state of literal string immutability in all recent RnRSes: """ In Scheme, strings are a mutable data type. Although it "is an error" (R5RS and R7RS) to use string-set! on literal strings or on strings returned by symbol->string, and any attempt to do so "should raise an exception" (R6RS), """ > -- > Taylan