Cadabra C++ library

All Cadabra functionality can be used directly from C++ programs without using the Python frontend.

A sample program can be found in c++lib/simple.cc:

#include "cadabra2++/Parser.hh"
#include "cadabra2++/Storage.hh"
#include "cadabra2++/DisplayTerminal.hh"
#include "cadabra2++/algorithms/substitute.hh"
#include "cadabra2++/algorithms/evaluate.hh"
#include "cadabra2++/TerminalStream.hh"
#include "cadabra2++/properties/PartialDerivative.hh"
#include "cadabra2++/properties/Coordinate.hh"

#include <iostream>
#include <sstream>


void test1()
    {
    // The following few lines are equivalent to entering
    //
    //    {r,t}::Coordinate.
    //    {m,n}::Indices(values={t,r}, position=free).
    //    ex:= A_{m} A^{m};
    //    rl:= A_{t} = 3 + a;
    //    evaluate(ex, rl);
    //
    // in the Cadabra notebook.

    cadabra::Kernel kernel;

    kernel.inject_property(new cadabra::Coordinate(), kernel.ex_from_string("{r,t}"), 0);
    kernel.inject_property(new cadabra::Indices(),    kernel.ex_from_string("{m,n}"),
                                  kernel.ex_from_string("values={t,r}, position=free"));
    
    auto ex = kernel.ex_from_string("A_{m} A^{m}");
    auto rl = kernel.ex_from_string("A_{t} = 3 + a ");
    cadabra::evaluate ev(kernel, *ex, *rl);
    ev.apply_generic();

    // Pretty-printing stream object.
    cadabra::TerminalStream ss(kernel, std::cerr);
    ss << ex << std::endl;
    }

void test2()
    {
    // The following few lines are equivalent to entering
    //
    //    {m,n,p,q}::Indices(position=free).
    //    \partial{#}::PartialDerivative;
    //    ex:= \int{ F_{m n} F^{m n} }{x};
    //    rl:= F_{m n} = \\partial_{m}{A_{n}} - \\partial_{n}{A_{m}};
    //    substitute(ex, rl, deep=True);
    //
    // in the Cadabra notebook.

    cadabra::Kernel kernel;
    
    auto ind1 = kernel.ex_from_string("{m,n,p,q}");
    auto ind2 = kernel.ex_from_string("position=free");
    kernel.inject_property(new cadabra::Indices(), ind1, ind2);

    auto pd   = kernel.ex_from_string("\\partial{#}");
    kernel.inject_property(new cadabra::PartialDerivative(), pd, 0);

    auto ex = kernel.ex_from_string("\\int{ F_{m n} F^{m n} }{x}");
    auto rl = kernel.ex_from_string("F_{m n} = \\partial_{m}{A_{n}} - \\partial_{n}{A_{m}}");

    // Pretty-printing stream object.
    cadabra::TerminalStream ss(kernel, std::cerr);

    ss << ex << std::endl;
    ss << rl << std::endl;

    // Apply the 'substitute' algorithm.
    cadabra::substitute subs(kernel, *ex, *rl);
    subs.apply_generic();

    ss << ex << std::endl;
    }


int main(int argc, char **argv)
    {
    test1();
    test2();
    }