ah-dispatcher.H File Reference

Command dispatcher pattern implementation. More...

#include <iostream>
#include <tpl_dynMapTree.H>

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Classes
class	AHDispatcher< Key, Operation >
	Tree-based command dispatcher. More...
class	AhHashDispatcher< Key, Operation >
	Hash-based command dispatcher. More...
struct	AhHashDispatcher< Key, Operation >::Equal

Detailed Description

Command dispatcher pattern implementation.

This file provides two dispatcher classes that map keys to callable operations, enabling dynamic command dispatching based on runtime keys.

Overview

A dispatcher is a registry that associates keys with operations (functions, lambdas, or function objects). At runtime, you can execute an operation by providing its key. This is useful for:

• Command-line argument handling
• Event-driven systems
• Plugin architectures
• State machines
• Menu systems

Available Dispatchers

Class	Backing Store	Lookup Time
AHDispatcher	DynMapTree (balanced tree)	O(log n)
AhHashDispatcher	ODhashTable (hash table)	O(1) average

Usage Example

#include <ah-dispatcher.H>
#include <functional>
 
// Define operations
int add(int a, int b) { return a + b; }
int sub(int a, int b) { return a - b; }
 
// Create dispatcher with string keys and function pointers
AHDispatcher<std::string, int(*)(int, int)> calc;
calc.insert("add", add);
calc.insert("sub", sub);
 
// Execute operations by key
int result = calc.run("add", 5, 3);  // returns 8
 
// Check if key exists
if (calc.valid_key("mul"))
  calc.run("mul", 2, 3);

With Lambdas

using Op = std::function<void(const std::string&)>;
AHDispatcher<std::string, Op> menu;
 
menu.insert("help", [](const std::string&) { 
  std::cout << "Available commands: help, quit\n"; 
});
menu.insert("quit", [](const std::string&) { 
  exit(0); 
});
 
menu.run("help", "");

See also

DynMapTree Tree-based map for AHDispatcher

ODhashTable Hash table for AhHashDispatcher

Author

Leandro Rabindranath León

Definition in file ah-dispatcher.H.