Module function_registry 

Function registry — scalar and aggregate function signatures.

Pre-populated with built-in functions at startup. Resolves function calls by name + argument types, selecting the best overload via implicit cast cost.

Structs

FunctionRegistry

Registry of all known functions.

FunctionSignature

A function signature: expected arg types and return type.

Enums

FunctionKind

Whether a function is scalar (row-at-a-time) or aggregate.