[stringtemplate-interest] Is $if()$ needed?

[Terence Parr]

On Aug 10, 2008, at 7:59 AM, Roman Odaisky wrote:

> Greetings,
>
> I wonder whether $if(attr)$ is redundant. Instead of
>
> $if(attr)$
> template
> $endif$
>
> one can write
>
> $attr:{template}$
>
> which looks cleaner.

But, you need

$if(attr)$, template$endif$

if you wanted to add a comma.  Oh, could do $attr:{, template}$ I  
guess. But, that only works for short templates.  IF works great for  
20 line inclusions.

> The only thing missing is the else part. Perhaps the grammar can be  
> extended,
> for example, this way:
>
> $attr:{if}$
> $attr:{if}!{else}$
> $attr!{else}$
>
> This also allows to test for more than one attribute:
>
> $[a, b]:{template}$
>
> “If” constructs come from the imperative world. ST doesn’t have  
> “for”, not
> even “foreach”, why should we have “if”?

An excellent question ;)  It needs some kind of conditional and the  
implied conditional of ':' would indeed work.

Ter