Re: Block comment syntax
David Michael writes: > Hi, > > The block comment documentation[1] claims that the closing "!#" must > appear on its own line, but this doesn't actually seem to be the > case[2]. For example, the line "(display #! comment !# 1)" > successfully outputs "1". > > Can anyone clarify whether the documentation needs to be updated, or > if the currently acceptable syntax is unintentional and should be > avoided? > > Thanks. > > David > > [1] > http://git.savannah.gnu.org/gitweb/?p=guile.git;a=blob;f=doc/ref/api-evaluation.texi;h=a23cf1ae48cf2724d5426eb3e0cf898afbf51604;hb=HEAD#l206 > [2] > http://git.savannah.gnu.org/gitweb/?p=guile.git;a=blob;f=libguile/read.c;h=c2d50afdfda158c8b06c20650009b7f3d175f27f;hb=HEAD#l1391 While I don't know the answer to your question, Guile 2.0.11 already seems to support the #| |# syntax, which has been standardized in R7RS, so I would recommend to use that for block syntax. Syntax highlighting in Emacs's scheme-mode seems to already know it too, in Emacs 24.3. Moreover, it can be nested (both per R7RS, and supported in Guile 2.0.11), whereas #! !# apparently can not. Taylan
Re: Block comment syntax
Taylan Ulrich Bayirli/Kammer : >> The block comment documentation[1] claims that the closing "!#" must >> appear on its own line, but this doesn't actually seem to be the >> case[2]. For example, the line "(display #! comment !# 1)" >> successfully outputs "1". >> >> Can anyone clarify whether the documentation needs to be updated, or >> if the currently acceptable syntax is unintentional and should be >> avoided? > > While I don't know the answer to your question, Guile 2.0.11 already > seems to support the #| |# syntax, which has been standardized in > R7RS, The "#!" syntax is there for one purpose only: to support the unix/linux hash-bang syntax. Every "scripting" language needs to support it. "#|" can't replace it. I wouldn't use "#!" anywhere else in a guile source file. http://en.wikipedia.org/wiki/Shebang_%28Unix%29> Marko
Re: Block comment syntax
On Tuesday, August 5, 2014 7:04 PM, David Michael wrote: > > >Hi, > >The block comment documentation[1] claims that the closing "!#" must >appear on its own line, but this doesn't actually seem to be the >case[2]. For example, the line "(display #! comment !# 1)" >successfully outputs "1". > >Can anyone clarify whether the documentation needs to be updated, or >if the currently acceptable syntax is unintentional and should be >avoided? The documentation needs to be clarified. The return used to be required back in Guile v1.6.x but now !# will terminate any block comment without a carriage return or line feed. If you're using #! block comments for containing shell script headers lines like "#!/bin/sh" or "#!/usr/bin/guile" it is a good idea to have the terminating !# on its own line, like the docs suggest, though. Best practice here is probably to use "#!" block comments only for containing shell script headers, and use the #| syntax otherwise. -Mike Gran
Re: Block comment syntax
On Wed, Aug 6, 2014 at 2:19 PM, Mike Gran wrote: > > On Tuesday, August 5, 2014 7:04 PM, David Michael > wrote: >> >> >>Hi, >> >>The block comment documentation[1] claims that the closing "!#" must >>appear on its own line, but this doesn't actually seem to be the >>case[2]. For example, the line "(display #! comment !# 1)" >>successfully outputs "1". >> >>Can anyone clarify whether the documentation needs to be updated, or >>if the currently acceptable syntax is unintentional and should be >>avoided? > > > The documentation needs to be clarified. The return used to > be required > back in Guile v1.6.x but now !# will terminate any block comment without > a carriage return or line feed. > > If you're using #! block comments for containing shell script headers > lines like "#!/bin/sh" or "#!/usr/bin/guile" > it is a good idea to have the terminating !# on its own line, like the > docs suggest, though. > > Best practice here is probably to use "#!" block comments only for > containing shell script headers, and use the #| syntax otherwise. > > -Mike Gran Thanks for the responses; I've restructured my script according to these suggestions. David
