crow

Utility library

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Markov Text Generator

Crow Library by Ross Smith

#include "crow/markov.hpp"
namespace Crow;

Markov class

enum class MarkovFlags: int {
    none       = 0,
    exclusive  = 1,
};

Bitmask flags controlling the behaviour of the Markov generator.

template <typename T, typename S = [see below]> class Markov {
    using string_type = S;
    using value_type = T;
    Markov() = default;
    explicit Markov(size_t context, size_t min_length = 1,
        size_t max_length = npos, MarkovFlags flags = none);
    void add(const S& example);
    template <typename RNG> S operator()(RNG& rng) const;
};

Markov chain based text generator. This can be used with any sequential container of a regular type. T is the element type; S is the container type. If T is a character type, S defaults to the corresponding string type; otherwise, S defaults to std::vector<T>.

The constructor arguments are:

• context – Number of preceding elements matched when generating the next one (default 2).
• min_length – Minimum length of an output sequence (default 1).
• max_length – Maximum length of an output sequence.
• flags – Behaviour flags.

If the exclusive flag is set, the generator will remember the list of sample sequences and will not generating any matching outputs.

The constructor will throw std::invalid_argument if context=0, min_length>max_length, or either length is zero.

The add() function adds a sample sequence to the generator’s corpus. Adding an empty sequence is ignored.

The function call operator generates a new output sequence.

using CMarkov = Markov<char>;
using SMarkov = Markov<std::string>;

Aliases for common instantiations.