[antlr-interest] Getting foreach working with StringTemplate for C#

[Christopher Brown]

Hi Michael,

Thankyou for taking the time to explain this to me.  I did try the
wiki but got misled (deadlines, deadlines, ...) by the "foreach"
example.  If it had been clearer that it was a "don't do this" code
snippet, followed by "here's how it's done in string template"
example, or if I'd had as much time as I'd've liked to read the doc
and explore the API, I suppose I'd've got it right by myself :-(  It
was only when I looked once again at the "multi-valued attribute"
section of the documentation that I figured out that that was where
"looping over collections/arrays" was covered.

It's both interesting and confusing therefore that the two syntaxes
below produce the same result:

$my_collection:my_item_template()$
$my_item_template(my_collection)$

The first just seems strange, the second seems more like functional
programming.  Is there a "better" way (of the two) or some things one
syntax can do that the other can't ?

Anyway, thanks again for taking the time to help me.  It's sincerely
appreciated!

- Christopher

On 01/03/2008, Micheal J <open.zone at virgin.net> wrote:
> > Hi,
>  >
>  > I'm still struggling with StringTemplate for C#, having
>  > looked through the lists, searched the web, and looked at the
>  > source code.
>
>
> Did you try the wiki?
>  http://www.antlr.org/wiki/display/ST/StringTemplate+Wiki+Home
>
>
>  > I can't get the following working (much simplified version of
>  > what I'm trying to achieve):
>  >
>  >   string tpl = "$foreach f in foo$ $f$ $end$";
>  >   //string tpl = "$foo$";
>  >
>  >   StringTemplate st = new StringTemplate(tpl);
>  >   st.SetAttribute("foo", new string[] {"a", "b", "c"});
>  >   Console.Out.WriteLine(st.ToString());
>  >
>  > If I switch the comment onto the first line, I get the array
>  > collapsed into a string with no separators.
>  >
>  > In my "real" scenario, which works with simple values, I just
>  > can't merge in arrays, lists, or anything enumerable.  I hope
>  > I'm doing something wrong -- that someone can explain to me
>  > -- because it seems such a basic task, I have trouble
>  > believing that it isn't implemented...!
>  >
>  > In the "real" scenario, I've also tried with group files and
>  > varying "dollar" and "angle bracket syntaxes", with no luck.
>  >
>  > Can anyone help?
>
>
>
> Sure. The template text you are supplying is NOT valid ST syntax. See
>  [http://www.antlr.org/wiki/display/ST/Five+minute+Introduction] for a basic
>  ST introduction (the basic syntax cheat sheet is useful for beginners)
>
>  Rather than:
>
>
>         $foreach f in foo$ $f$ $end$
>
>
>
> Try (either of) these instead:
>
>         $foo:{f| $f$ }$
>
>         OR
>
>         <foo:{f| <f> }>
>
>
>
>  Micheal