Question: I have been using template toolkit for extending an existing domain specific language(verilog) for over 3 years now. While overall I am happy with it, the major irritant is that when there is a syntax/undef error the error message does not contain the correct line number information to debug the error.

e.g. I would get a message indicating "0 is not defined" since I would be using [%x.0%] and similar constructs at multiple locations in the file figuring out which line has the problem becomes difficult.

TT3 seems to be under development indefinitely

My question to the gurus is is there a better alternative to TT. My requirements are

1. Support for complex data structures
2. Good error reporting and debug capabilities.
3. Stable and proven ( no alpha/beta level engines)
4. Extensible (plugin's etc)
5. Should not be restricted to a given language (html etc.)
6. support for IF/Else, looping(foreach while), Loop indexing, etc.
7. Preferably perl
8. Support for data dumper or equivalent plugin from within the template is a plus

Answer: 
I'm currently experimenting with [Template::Alloy](https://metacpan.org/module/Template::Alloy) and it seems to be, by and large, a drop-in replacement for TT. [Template::Alloy::TT](https://metacpan.org/module/Template::Alloy::TT) lists the differences between TT and Alloy, most of which are of the form "This works/is allowed in Alloy, but not in TT." Addressing your specific issue, the list includes:

> 
> * Alloy has better line information
> 
> 
> When debug dirs is on, directives on different lines separated by
>  colons show the line they are on rather than a general line range.
> 
> 
> Parse errors actually know what line and character they occured at.
> 
> 
>
take a look on [Template::Semantic](http://search.cpan.org/~tomita/Template-Semantic/) for pure template abstraction