funcs

Documentation

Overview

Package funcs is the curated registry of inline txcl functions — the `&name(args...)` runtime calls that complement `txco://` ops. Functions are side-effect-free (no Unit access, no I/O, no bus dispatch, no suspend); they exist to give rule authors inline computation for things like base64 decoding, UUID generation, or path access without paying the bus-and-trace overhead of a full op invocation.

New entries are added with discipline — see internal docs/todo-txcl-expressions.md §4 ("Discipline about what goes in"). PR 3 ships just two pilots: &uuid() and &now().

Index

• func Call(name string, args []any) (any, error)
• func Has(name string) bool
• type Func

Functions

func Call

func Call(name string, args []any) (any, error)

Call dispatches `name` through the registry with the already- resolved args. Returns (nil, error) on unknown name; otherwise the function's return value.

Single entry point used by runtime.Resolve when it walks a FunctionCall node. No other caller in the codebase should invoke registered functions directly.

func Has

func Has(name string) bool

Has reports whether a function is registered. Useful for parser- time / validate-time lookups that want to flag unknown functions before the rule fires (deferred — PR 3 only does runtime dispatch; validate-time integration is a follow-up).

Types

type Func

type Func func(args []any) (any, error)

Func is the signature every registered function shares. Args arrive already resolved (the runtime evaluator walked any nested FunctionCalls / PathRefs / Literals before calling here), so implementations only see concrete Go values.

Implementations MUST be:

• synchronous and quick (no I/O, no Unit access);
• side-effect-free with respect to chassis state (the nondeterminism in &uuid / &now is OK — they don't mutate anything observable);
• safe for concurrent invocation (a single Func may be called from many rules / goroutines at once).

On error, return (nil, err). The runtime propagates the error up to the rule as a strict halt (see internal docs/todo-txcl-expressions.md §5). The `&try_*` safe variants (added in PR 4) swallow errors from the corresponding strict form and substitute nil instead.