Re: [jamboost] Jam's space-sensitivity

From: Zbynek Winkler (zw-bjam_at_[hidden])
Date: 2005-01-26 07:27:26

Vladimir Prus wrote:

>Hi,
>all most of you know, Jam is sensitive to spaces. A typical first user's error 
>is:
>
> exe a : a.cpp;
>
>The attached patch attempts to fix that. Now, whenever bjam sees ';' outside 
>of quited string, it terminates the current token.
> 
>
It was my first user error too ;-). However, the rule is simple and 
works for all cases - just put spaces everywhere. I think there is a 
certain beauty to the simplicity. I'd suggest instead to detect this 
particular case but return error saying that this is the most often 
first time error and that spaces are needed everywhere. I think it would 
help the users more in this way...

>It would be good to handle other symbols ( '[', ']', ':' ) in the similar way, 
> 
>
So currently any character can be a part of string as long as there are 
no spaces in it? Or what is the exact rule? I don't see it in the 
documentation :(. I think it should be as understandable as possible - 
so either go with "no special characters outside of nonquoted string" 
(like all the other languages I know) or leave it the way it is (and 
document it).

>but unfortunately, they can appear inside variable accesses, for example:
>
> gFILES($(targets[1])) = fff ;
>
>During scanning, it's not easy to find if we're inside variable access or 
>not, so those symbols can't be safely handled.
> 
>
Unfortunatelly, I do not understand what the problem is here. Going with 
the least surprise behaviour I'd say that 'targets' is an array, we take 
item with index '1' and give that as a parametr to function call of 
'gFILES', take its return value and assign 'fff' to it. But then it 
would be php and not jam and there would be no problem with the 
scanning... Is it just me or is the jam language "strange"? I am eagerly 
waiting for the python port... ;-)

>Opinions? Should I commit this?
> 
>
All is above.

Zbynek

-- 
http://zw.matfyz.cz/ http://robotika.cz/
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic