selftemplating

Selftemplating is a term used in programming and templating systems to describe templates that can produce their own representation or other templates, enabling meta templating or bootstrapping.

The concept sits at the intersection of template processing, metaprogramming, and code generation. It is related to, but distinct from, a quine, which is a program that outputs its own source code; selftemplating applies the idea within the domain of templates and templating engines.

In many systems, templates are composed of static content and dynamic placeholders. Selftemplating arises when the template includes a representation of its own syntax or when the rendering process produces a template as output that can be re-fed into the engine. Techniques include representing templates as data structures within the language, recursive rendering, and bootstrapping where a template engine is used to generate its own engine or starter templates.

Examples include a template engine that can render a template language's grammar from a single source file; a template that outputs another template with the same placeholders; and a bootstrapping setup where the first generated artifact is a minimal engine, followed by more featureful templates.

Applications and challenges: Useful in bootstrapping, self-hosted template engines, and meta-documentation. Challenges include increasing complexity, risk of recursion errors, and security considerations when templates generate code.