// Accepts valid Brainfun programs, which consist of the characters:
// '>' '<' '+' '-' '.' ',' '[' ']' '~' '!' 
// Any other character in a Brainfun is considered to be a comment and should be ignored
//
// A Brainfun program is considered invalid if:
//      - there are mismatching opening and closing square brackets.
// If a Brainfun program is found to be invalid, the exception Error is raised at the main
//
// Meaning of each character:
// |-----------|--------------------------------------------------------------------------------------------|
// | Character |                                         Meaning                                            |
// |-----------|--------------------------------------------------------------------------------------------|
// |     >     | Increment the data pointer by one (to point to the next cell to the right).                |
// |-----------|--------------------------------------------------------------------------------------------|
// |     <     | Decrement the data pointer by one (to point to the next cell to the left).                 |
// |-----------|--------------------------------------------------------------------------------------------|
// |     +     | Increment the byte at the data pointer by one.                                             |
// |-----------|--------------------------------------------------------------------------------------------|
// |     -     | Decrement the byte at the data pointer by one.                                             |
// |-----------|--------------------------------------------------------------------------------------------|
// |     .     | Output the byte at the data pointer.                                                       |
// |-----------|--------------------------------------------------------------------------------------------|
// |     ,     | Accept one byte of input, storing its value in the byte at the data pointer.               |
// |-----------|--------------------------------------------------------------------------------------------|
// |     [     | If the byte at the data pointer is zero, then instead of moving the instruction pointer    |
// |           | forward to the next command, jump it forward to the command after the matching ] command.  |
// |-----------|--------------------------------------------------------------------------------------------|
// |     ]     | If the byte at the data pointer is nonzero, then instead of moving the instruction pointer |
// |           | forward to the next command, jump it back to the command after the matching [ command.     |
// |-----------|--------------------------------------------------------------------------------------------|

// Table taken from https://en.wikipedia.org/wiki/Brainfuck
//
// After each character is read, the Brainfun coroutine writes a corresponding line of C code to the output

#pragma once

#include <fstream>
#include <iostream>
#include <string>

_Coroutine Brainfun {
    std::ostream * out;             // output stream
    char ch;                        // character passed by cocaller
    
    // YOU ADD MEMBERS HERE

    void main();                    // coroutine main

  public:
    _Exception Error {};            // thrown at main if program is invalid
    _Exception EndOfFile {};        // thrown at coroutine to indicate EOF

    void next( char c ) {
        ch = c;                 // communication input
        resume();               // activate
    } // Brainfun::next

    // You may add a public construtor
    // DO NOT ADD ANY OTHER PUBLIC MEMBERS
}; // Brainfun

// Local Variables: //
// mode: C++ //
// compile-command: "make brainfun" //
// End: //