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Re: How do feel people about the following change in syntax?
From: |
David Kastrup |
Subject: |
Re: How do feel people about the following change in syntax? |
Date: |
Wed, 12 Oct 2011 20:19:57 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) |
David Kastrup <address@hidden> writes:
> Graham Percival <address@hidden> writes:
>
>> What happens if somebody writes
>> { \with foo c4 \with bar d4 }
>> ?
>
> Good catch. I don't think we want anything but a syntax error here.
> One approach would be not to ignore Scheme expressions in a sequence
> unless they evaluate to "unspecified" or at least a limited set of
> "ignorable" values.
>
> More compatible would be the approach that you can omit braces only when
> a certain construct is syntactically expected somewhere: if it is to be
> produced "foreignly", use # or { ... }. Then
>
> { { \with foo } c4 { \with bar } d4 }
>
> would be a music sequence with two Scheme expressions inside getting
> ignored, and { \with foo c4 \with bar d4 } would be a syntax error.
On the other hand: why silently ignore a likely side-effect-free
expression? It is likely to be a programmer error. So I lean towards
ignoring only expressions with "unspecified" value (basically all Scheme
assignments) for the first attempt. If tests with real-world documents
show this to be too disruptive, one can think about alternatives.
One can still mark expressions only used for side-effect with \ignore
with the definition
ignore = #(define-scheme-function (parser location arg) (scheme?)
(set! arg arg))
or similarly (guile seems a bit peculiar with regard to completely
omitted function bodies).
--
David Kastrup
- How do feel people about the following change in syntax?, David Kastrup, 2011/10/12
- Re: How do feel people about the following change in syntax?, Graham Percival, 2011/10/12
- Re: How do feel people about the following change in syntax?,
David Kastrup <=
- Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/18
- Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/18
- Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/18
- Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/19
- Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/20
Re: How do feel people about the following change in syntax?, David Kastrup, 2011/10/12