capability

Documentation

Overview

Package capability lets an embedder narrow what DTL code may do as execution crosses into a user-defined function.

DTL itself has no notion of who owns a function or what it is allowed to touch — that is the embedder's model. So this package carries no policy: it provides the hook the executor calls, and the embedder supplies the meaning.

Absence means unrestricted, deliberately. An embedder that installs no interceptor gets a plain interpreter.

Index

• func Enter(ctx context.Context, functionName string) context.Context
• func WithInterceptor(ctx context.Context, fn Interceptor) context.Context
• type Interceptor
  • func From(ctx context.Context) Interceptor

Functions

func Enter

func Enter(ctx context.Context, functionName string) context.Context

Enter is called by the executor immediately before running a user function. With no interceptor installed the gate is inert.

func WithInterceptor

func WithInterceptor(ctx context.Context, fn Interceptor) context.Context

WithInterceptor attaches an Interceptor to ctx. A nil Interceptor attaches nothing, so callers need not branch.

Types

type Interceptor

type Interceptor func(ctx context.Context, functionName string) context.Context

Interceptor re-scopes ctx as execution enters functionName. Returning ctx unchanged leaves the caller's authority in place.

func From

func From(ctx context.Context) Interceptor

From returns the Interceptor in ctx, or nil.