Skip to content

Latest commit

 

History

History
87 lines (57 loc) · 6.9 KB

index.md

File metadata and controls

87 lines (57 loc) · 6.9 KB
Raw

CppML Documentation

A concise and readable metaprogramming language for C++

CppML is a metalanguage for C++. It was designed to simplify the process of creating intricate classes, by letting the programmer design them through expressions that feel like algorithms in a functional language. It strives to be easy to write and easy to read, while being efficient. It does so by providing compositional pipelines through which parameter packs can flow without instantiating new types. Our goal is to give library developers programmatic control over the creation of class hierarchies with metaprograms that shape their structure and behaviour through metafunctional logic. This way constructions of complex designs are easily encoded in concise and readable functional expressions.

An illustrative example is generating a tagged hierarchy of classes, which is used by some implementations of a tuple. We want a metafunction MakeBase, where e.g. MakeBase<T0, T1, T2, T3> is equivalent to:

Elem<Tag<ml::Int<0>, T0>,
     Elem<Tag<ml::Int<1>, T1>,
          Elem<Tag<ml::Int<2>, T2>, Elem<Tag<ml::Int<3>, T3>>>>>;

Using CppML we can express MakeBase as a simple metaprogram:

template <typename... Ts>
using MakeBase = ml::f<
    ml::ZipWith<Tag, ml::Map<ml::Curry<ml::F<Elem>>, ml::F<ml::Compose>>>::f<
        ml::Range<>::f<0, sizeof...(Ts)>, ml::ListT<Ts...>>,
    EmptyBase>;

To get started please see our User Documentation, where we provide an Instalation Guide, an in-depth Tutorial of the CppML language and a detailed CppML Reference.

Table of Contents

Installation

CppML can be installed in two ways. You can install it using cmake as an INTERFACE library, or you can embed it in your project (e.g. via git submodules or direct-copy).

You may follow the Installation Guide for your convenience.

Tutorial

CppML provides an in-depth Tutorial of the CppML language and its libraries.

Abstract

In this tutorial, we will go over the design of the CppML language and explore its prominent features in depth. You will learn about compositional pipelines and the flow of parameter packs through them. You will learn about the structure of metafunctions, how to understand their metafunction type, and how they integrate with pipelines. You will learn how to manipulate metafunctions using concepts like Currying, Product Maps and Branch Pipes, and how to compose them into algorithms that will build your class designs.

Interspersed throughout the tutorial are use-cases, where we will formulate a problem and break down its solution into steps, and than translate them into CppML. Through them you will learn how to encode construction of (increasingly) complex designs into concise and readable functional expressions.

Please see the Tutorial of the CppML language.

CppML Reference

CppML comes with a detailed CppML reference. Each construct provides a specification of its structure, a definition of its metafunction type, and an example of use. The constructs of CppML are divided in into several smaller libraries, which are described below:

Library Description
Algorithm Algorithms over parameter packs (e.g. Sort, ZipWith, etc.)
Arithmetic Arithmetic operations on type-values (e.g. Greater, Not, etc.)
Functional Manipulation of metafunctions (e.g. Curry, Map, etc.)
Pack Manipulation of parameter packs (e.g. Drop, Get, etc.)
TypeTraits Insights into types (e.g. IsSame, IsClass, etc.)
Vocabulary Vocabulary types of CppML (e.g. ListT, Value, etc.)

Please see the complete CppML reference, for additonal details.

Structure

CppML is structured as follows:

  • each library has an associated header .hpp and a directory of the same name in the CppML/ directory. For example, the Algorithm library has an Algorithm.hpp header located in the include/CppML
  • every component of each library has a dedicated .hpp header inside the libraries associated directory. For example, Sort, a component of the Algorithm library, has a header located at include/CppML/Algorithm/Sort.hpp.

Thus, to use any component, you can either include its specific header (e.g. #include <CppML/Algorithm/Sort.hpp>), or include its libraries header #include <CppML/Algorithm.hpp>. Note that you may include all libraries at once using #include <CppML/CppML.hpp>.

Testing

CppML provides tests for each of its components, which are automatically built with Github Actions on each push. Please see the Testing Guide for instructions on how to build them, and additional details.

License

CppML is distributed under the MIT License. Please see the accompanying LICENSE in the root of the project.