How to use ~c with v parameter in (ice-9 format)?

How to use ~c with v parameter in (ice-9 format)?

[Tomas Volf]

[-- Attachment #1: Type: text/plain, Size: 1089 bytes --]


Hello,

when reading the documentation for (ice-9 format), this part of
description of ~c caught my eye:

> If the charnum parameter is given then an argument is not taken but
> instead the character is (integer->char charnum) (see
> Characters). This can be used for instance to output characters given
> by their ASCII code.

I wanted to give it a try, so I took the example from documentation and
run it in a REPL.

--8<---------------cut here---------------start------------->8---
scheme@(guile-user)> ,use (ice-9 format)
scheme@(guile-user)> (format #f "~65c")
;;; <stdin>:29:0: warning: "~65c": wrong number of `format' arguments: expected 1, got 0
$7 = "A"
--8<---------------cut here---------------end--------------->8---

So, it does indeed return "A", however is also prints a warning.  Am I
doing something wrong?  Or is the documentation out-dated and `charnum'
parameter should be used in a different way?

Have a nice day,
Tomas

-- 
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 853 bytes --]

Re: How to use ~c with v parameter in (ice-9 format)?

[Tomas Volf]

PS: The subject is misleading.  I originally noticed the warning with ~vc, but during writing the email realized that ~65c warns as well and forgot to adjust it.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Re: How to use ~c with v parameter in (ice-9 format)?

[Matt Wette]

On 11/10/24 3:39 PM, Tomas Volf wrote:
> Hello,
>
> when reading the documentation for (ice-9 format), this part of
> description of ~c caught my eye:
>
>> If the charnum parameter is given then an argument is not taken but
>> instead the character is (integer->char charnum) (see
>> Characters). This can be used for instance to output characters given
>> by their ASCII code.
> I wanted to give it a try, so I took the example from documentation and
> run it in a REPL.
>
> --8<---------------cut here---------------start------------->8---
> scheme@(guile-user)> ,use (ice-9 format)
> scheme@(guile-user)> (format #f "~65c")
> ;;; <stdin>:29:0: warning: "~65c": wrong number of `format' arguments: expected 1, got 0
> $7 = "A"
> --8<---------------cut here---------------end--------------->8---
>
> So, it does indeed return "A", however is also prints a warning.  Am I
> doing something wrong?  Or is the documentation out-dated and `charnum'
> parameter should be used in a different way?
>
> Have a nice day,
> Tomas
>

This looks like a bug in the compiler to me.
For example, check the `format-analysis' procedure in 
language/tree-il/analyze.scm

try this: (apply format #f "~65c" '())

Matt

Re: How to use ~c with v parameter in (ice-9 format)?

[Tomas Volf]

[-- Attachment #1: Type: text/plain, Size: 555 bytes --]

Matt Wette <matt.wette@gmail.com> writes:

> This looks like a bug in the compiler to me.

Will send a bug report.

> For example, check the `format-analysis' procedure in
> language/tree-il/analyze.scm

I had a look, but have to admit that procedure is beyond me, at least
for now.

>
> try this: (apply format #f "~65c" '())

Yes, this works great, will use this as a work around.  Thanks :)

Have a nice day,
Tomas

-- 
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 853 bytes --]