/////
// Musa Al-hassy
// January 2017
// McMaster University
/////

/*
* This is header is for an embedded domain specific language: Dijkstra's guarded command language.
*
* In doubt, run
*
*                  gcc -E myfile.c 
*
* to and look at the offending line to find out what's wrong!
*/

#include <stdlib.h> // to use exit(n)

#define bool int  // it's probably better to use a typedef..
#define true 1
#define false 0

#define BEGIN      {
#define END        }
#define TERMINATOR ;

// notice the lack of trailing/terminating semi-colons at the end of driver-code ;)
// we're mimicking GCL guarded statements and so using their approach to
// semicolons as separators, for sequencing, rather than terminators

#define IF if (false) {
#define FI TERMINATOR END else {exit(EXIT_FAILURE);} // end the IF-many and end the recent most then-clause
// NEEDS TO crash/abort if none of the guards work! As per GCL specs!

// "guard B then S"  ~~>  " } else if (B) {S "
#define guard TERMINATOR END else if (
#define has  ) BEGIN

#define DO while(true) BEGIN IF
#define OD TERMINATOR END else break; END  // end previous guard, end the IF, exit loop, end loop body

// type agnostic swap operation
#define swap(x, y) { typeof(x) temp = x; x = y; y = temp; }