The plot

They are either pure interpolators or (more or less) fullblown interpreters. Pure interpolators are modules like CGI::FastTemplate which will intentionally do absolutely nothing other than substitute variable names for values. Interpreters are modules like HTML::Template, TemplateToolkit2, HTML::Mason, AxKit and You::Name::It which will let you create templates that look more like some code source than HTML.

Mounting tension

Now I have a problem with both. Interpolators lead to a proliferation of microscopic tiny snippet templatelets whenever you try to produce tables, esp if there are different types of rows of which one gets chosen depending on some of the variables, or tables are nested, or (the Camel help me) a mix of both. Interpreters do solve this problem - but intersparsed with commands in arbitrary places and using visually complex constructs for the simple task of variable interpolation, their templates become a chore to read, much less write, not to mention that beyond a certain degree of complexity and flexibility (such as may be tempting to use with TemplateToolkit2) they go way above webdesigners' heads, putting the programmer back in the position of layout maintainer.

Climax

So what I am almost about to write is something that lies inbetween: CGI::FastTemplate-like syntax for interpolation, and SSI-like syntax for higher level constructs. On CPAN, there is nothing that meets these criteria. The Big Question is - does anyone know of an already ongoing effort for this kind of module?

Aftermath

If not, then here's a sneak peek at my overall idea: there will only be a single highlevel construct, a loop command that doubles as a conditional construct. Nested data structure interpolation will be supported by a dot operator ( "$[foo.bar]" = $templatevars->{foo}->{bar} ), with variables usable as part of variable names ( "$[foo.$bar]" = $templatevars->{foo}->{$templatevars->{bar}} - needs some thought about how exactly to disambiguate "$[foo.$bar.$baz]"). Comments?