PodExpression<T> class abstract interface

Pod Expression Contract

Represents an abstract, generic expression that evaluates into a Pod or related object in the dependency injection container.

A PodExpression is part of the evaluation pipeline for JetLeaf-style dependency injection. It acts like an AST (abstract syntax tree) node that can be:

  • A literal reference to a pod.
  • A composite expression combining multiple pods.
  • A dynamic expression resolved at runtime.

The generic type parameter T represents the expected result type of the evaluation, typically the type of object the pod produces.

Usage

Developers typically do not implement PodExpression directly. Instead, it is used by the DI framework when parsing, combining, or lazily evaluating pod configurations.

Example:

final expr = SomeConcretePodExpression<String>();
final context = PodExpressionContext(factory, scope);

// Evaluates expression into an ObjectHolder<String>
final result = expr.evaluate(context);
print(result.getPod()); // e.g., prints a singleton String pod

Notes for Implementors

  • Must be immutable and thread-safe.
  • Should perform minimal work until evaluate is invoked.
  • Designed to support async or sync evaluation (via FutureOr).
Annotations
  • @Generic.new(PodExpression)

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

evaluate(PodExpressionContext context) → FutureOr<ObjectHolder<T>>
Evaluate the Pod Expression
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited