Metaprogramming

This section describes the compile-time extension surface of FOL.

Metaprogramming facilities allow source to be generated, transformed, or specialized before normal execution semantics apply.

The chapter family currently covers:

• built-ins
• macros
• alternatives
• defaults
• templates

These features are powerful but high-risk for readability. They should be used to remove repetitive structure, not to obscure ordinary program logic.