# commander

`software.visionary:commander:2026.10.13` · https://codeberg.org/iluvatar/commander

Visionary Software Solutions Commander: COMMAND — bidirectional adaptation between java.lang.Runnable and Command.

Canonical Command design pattern abstractions providing first-class command execution and bidirectional adaptation with java.lang.Runnable.

## Rationale

**Why.** Standardizing execution contracts around the Gang of Four Command pattern clarifies intent and enables bidirectional Runnable interop.

**Problem.** Over-reliance on plain Runnable obscures domain intent and misses opportunities for structured, parameterized command pipelines.

**Solution.** Command is the execution abstraction; CommandFactory builds one from whatever a caller has on hand; Commands is the singleton AGGREGATE ROOT that adapts a Runnable to a Command and a Command to a Runnable, contract-checked at the boundary.

## Key Concepts

### Command

**Role.** Foundational command execution interface.

**Pattern.** Command

### CommandFactory

**Role.** Makes a Command from what it needs to do its job; the general shape every command factory shares.

**Pattern.** Factory

### Commands

**Role.** Singleton AGGREGATE ROOT that adapts a Runnable to a Command and a Command to a Runnable.

**Pattern.** Adapter

## How It Works

**Guarantees.** Guarantees lossless delegation and exception propagation across command and runnable invocations. It reads nothing at run time.

**Thread safety.** Stateless command adapters are thread-safe.

## Lane

**Purpose.** Domain execution abstraction and runnable adaptation lane.

**Alternative.** For direct JVM threads, use java.lang.Runnable directly.

## Usage

Executing and adapting commands

```java
Command cmd = () -> System.out.println("Executing");
cmd.execute();
Runnable runnable = Commands.INSTANCE.adapt(cmd);
Command adapted = Commands.INSTANCE.adapt(runnable);
```

## Dependencies

- `software.visionary.contrax:processor:2026.10.13` at Processor
- `software.visionary:junit-closure:2026.09.17` at Testing

## Caveats

- Command executions propagate unchecked runtime exceptions thrown by underlying actions.