What I'm looking for is a standalone general purpose templating engine. I envision this to meet the following criteria
- Available as a single binary with a CLI interface
- Ingests common data formats (i.e. JSON, etc.)
- Exports textual data of any format
The primary use-case is not generating HTML, but rather various textual data with differing structural requirements. It's very hard to search in this space because you're inevitably met with Javascript solutions aiming to template HTML. I'd prefer not to be tied to a JS runtime and the idiosyncrasies of trying to template HTML.
Taking input from JSON is probably rarer because all of them are programming language focused.
For CLI, you could combine it with things like jq (there was also something else that allowed using css selectors on JSON) and other tools like awk.
Or you could simply use PHP for a built in templating language (i.e. put ?> statements into whatever your file format is).
If you're familiar with UNIX tools you could probably do a lot with the shell, sed, and awk.
Knowing Perl might be useful in this situation, too, and it's an old and stable language with a huge library of modules (CPAN).
Built to generate anything, works on directories of files for input / output. CUE is the primary input, which means JSON & Yaml are also supported. It also supports writing custom code in the output, changing your designs and regenerating, while not losing the custom parts.