dispatcher_example.C File Reference

Dispatcher pattern in Aleph-w (ah-dispatcher.H) with tree and hash backends. More...

#include <iostream>
#include <iomanip>
#include <string>
#include <functional>
#include <sstream>
#include <ah-dispatcher.H>
#include <tpl_dynArray.H>

Include dependency graph for dispatcher_example.C:

Go to the source code of this file.

Namespaces
namespace	Calculator
	Basic arithmetic operations for the calculator.

Functions
void	print_header (const string &title)
void	print_subheader (const string &subtitle)
double	Calculator::add (double a, double b)
double	Calculator::sub (double a, double b)
double	Calculator::mul (double a, double b)
double	Calculator::div (double a, double b)
double	Calculator::mod (double a, double b)
double	Calculator::pow (double a, double b)
void	demo_calculator ()
void	demo_text_processor ()
void	demo_regions_menu ()
void	demo_state_machine ()
void	demo_hash_dispatcher ()
void	demo_variadic_dispatcher ()
int	main ()

Detailed Description

Dispatcher pattern in Aleph-w (ah-dispatcher.H) with tree and hash backends.

Overview

This example demonstrates Aleph-w's dispatcher containers: maps from keys (typically std::string) to callables (functions, lambdas, functors) enabling command-style dispatch without long if/else chains.

It includes multiple demos (calculator, text transforms, menu, state machine) and compares tree-backed vs hash-backed dispatch.

Data model used by this example

• Keys: std::string
• Values: callables such as std::function<...> or function pointers

Algorithms and Aleph-w API

Containers shown:

• AHDispatcher<Signature>: ordered/tree-based dispatcher
• AhHashDispatcher<Signature>: hash-based dispatcher

Typical operations:

• registration: disp[key] = callable;
• lookup/execute: if (disp.has(key)) disp[key](...);

Complexity

Let n be the number of registered commands.

• Tree-backed dispatcher: lookup/insert O(log n)
• Hash-backed dispatcher: lookup/insert O(1) average

Usage

./dispatcher_example

This example has no command-line options; it runs all demos.

Pitfalls and edge cases

• If you use operator[] to execute, ensure the key exists or use has() first.
• Hash dispatch has no ordering; tree dispatch preserves key order.

References / see also

• ah-dispatcher.H
• dynmap_example.C / dynset_trees.C (ordered containers and backends)

Author

Leandro Rabindranath León

Definition in file dispatcher_example.C.

Function Documentation

demo_calculator()

void demo_calculator

(

)

Definition at line 146 of file dispatcher_example.C.

References Calculator::add(), Aleph::DynList< T >::append(), Calculator::div(), Aleph::DynList< T >::insert(), Aleph::maps(), Calculator::mod(), Calculator::mul(), Calculator::pow(), print_header(), Aleph::HTList::size(), and Calculator::sub().

Referenced by main().

demo_hash_dispatcher()

void demo_hash_dispatcher

(

)

Definition at line 456 of file dispatcher_example.C.

References Aleph::DynList< T >::append(), Aleph::DynList< T >::insert(), Aleph::maps(), print_header(), and Aleph::HTList::size().

Referenced by main().

demo_regions_menu()

void demo_regions_menu

(

)

Definition at line 281 of file dispatcher_example.C.

References Aleph::DynList< T >::append(), Aleph::DynList< T >::insert(), Aleph::maps(), print_header(), and Aleph::HTList::size().

Referenced by main().

demo_state_machine()

void demo_state_machine

(

)

Definition at line 356 of file dispatcher_example.C.

References Aleph::DynList< T >::insert(), log(), Aleph::maps(), and print_header().

Referenced by main().

demo_text_processor()

void demo_text_processor

(

)

Definition at line 197 of file dispatcher_example.C.

References Aleph::DynList< T >::append(), Aleph::count(), Aleph::DynList< T >::insert(), GenericItems< Container, T >::keys(), Aleph::maps(), print_header(), Aleph::HTList::size(), Aleph::to_string(), Aleph::tolower(), and Aleph::toupper().

Referenced by main().

demo_variadic_dispatcher()

void demo_variadic_dispatcher

(

)

Definition at line 531 of file dispatcher_example.C.

References Aleph::DynList< T >::append(), Aleph::DynList< T >::insert(), Aleph::maps(), print_header(), Aleph::HTList::size(), and Aleph::to_string().

Referenced by main().

main()

int main

(

)

Definition at line 591 of file dispatcher_example.C.

References demo_calculator(), demo_hash_dispatcher(), demo_regions_menu(), demo_state_machine(), demo_text_processor(), demo_variadic_dispatcher(), and Aleph::maps().

print_header()

void print_header

(

const string &

title

)

Definition at line 108 of file dispatcher_example.C.

References Aleph::maps().

print_subheader()

void print_subheader

(

const string &

subtitle

)

Definition at line 116 of file dispatcher_example.C.

References FunctionalMethods< Container, T >::length(), and Aleph::maps().