####COMS 4115 Project: Quantum Computing Language

A language and compiler implemented in OCaml to build quantum circuits.

####Instructions

• Install Vagrant
• Install VirtualBox
• Open the repo directory and run vagrant up
• Run vagrant ssh to ssh into the Vagrant box running Ubuntu 14.04 LTS with OCaml and g++4.8 installed
• Make sure you are in the /vagrant directory. If not, run cd /vagrant.

###Compiling and Running Quark Programs The following Hello World example Quark program is saved in /tests/hello_world.qk.

def int main:
{
    print("hello world");

    return 0;
}

Before we can compile Quark programs into C++ we must build the Quark compiler quarkc. Navigate to /vagrant/quark/ and run make. Ensure quarkc was properly built by checking for error messages then running ./quarkc -h to see compilation options. You should see the following:

usage: quarkc -s source.qk [-c output.cpp ] [-o executable] [-static] [-g++ /path/to/g++]
  -s : quark source file
  -c : generated C++ file. If unspecified, print generated code to stdout
  -o : compile to executable. Requires g++ (version >= 4.8)
  -sco : shorthand for -s <file>.qk -c <file>.cpp -o <file>
  -sc : shorthand for -s <file>.qk -c <file>.cpp
  -g++ : shorthand for -s <file>.qk -c <file>.cpp
  -static : compile with static lib (otherwise with dynamic lib). Does NOT work on OSX
  -help  Display this list of options

As stated above, to compile tests/hello_world.qk into C++ and an executable run ./quark/quarkc -s tests/hello_world.qk -c hello_world.cpp -o hello_world. You can run the hello_world executable ./hello_world to get the output, and the cat command shows the generated C++ as follows:

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ ./hello_world
hello world

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ cat hello_world.cpp
#include "qureg.h"
#include "qumat.h"
#include "qugate.h"
#include "quarklang.h"

using namespace Qumat;
using namespace Qugate;

int main()
{
std::cout << std::boolalpha << std::setprecision(6) << std::string("hello world") << std::endl;
return 0;
} // end main()

The C++ includes are referencing our quantum simulator and these files can be found in the lib directory.

To run some quantum computing programs, compile shor.qk and grover.qk in the quark folder. They are examples of non-trivial programs performing Shor's algorithm and Grover's search. More information on them in the testing section.

Given an actual quantum computer, we would be able to run these algorithms in the stated time. For now, we run them on our simulator in exponential time for small N examples.

Shor's algorithm can factorize large integers in polynomial time. Run ./quark/quarkc -s quark/shor.qk -c shor.cpp -o shor and then run the executable./shor

Grover's search can search an unsorted database in O(N^1/2) time. Run ./quark/quarkc -s quark/grover.qk -c grove.cpp -o grover and then run the executable ./grover

####Team In lexicographical order: