/**
 * Constants
 */
const str nl = "\n";

/**
 * Print with a newline
 */
function pln(str string) {
    for (byte c in string) {
     putchar(c);
    }
    putchar(nl);
}

/**
 * Concatinates 2 strings
 */
function concat(str src1, str src2) str {
    str result = malloc(src1.length + src2.length);
    memcpy(result[0].ptr, src1.ptr);
    memcpy(result[src1.length].ptr, src2.ptr);
    return result;
}

/**
 * finds index of string, -1 if not found
 */
function str_index_of(str haystack, byte needle) int {
   int i = -1;
   for (byte c in haystack) {
     i = i + 1;
     if (c == needle) {
       break;
     } 
   }
   return i;
}

/**
 * checks if 2 strings are equal
 */
function str_eq(str src1, str src2) bool {
  if (src1.length != src2.length) return false;
  for (int i=0; src1.length; i++) {
    if (src1[i] != src2[i]) return false; 
  }
  return true;
}

/**
 * Slice string
 */
function str_slice(str src, int start, int stop) str {
   int len = stop - start;
   str result = malloc(len); 
   for (int i=start; i<stop; i++) {
     result[i] = src[i];
   }
   return result;
}

/**
 * int to string
 */
function itos(int src) str {
	byte buffer[6];
	nat i = 6;
  bool neg = n < 0;

  if (neg) n = -n;

  do {
      buffer[--i] = '0' + n % 10;
      n /= 10;
  } while(n > 0);

  if(neg) buffer[--i] = '-';

  str result = malloc(6 - i); 
  memcpy(result, buffer[0].ptr + i, 6 - i);
  return result;
}

/**
 * nat to string
 */
function ntos(nat src) str {
	byte buffer[5];
	nat i = 5;
  
  do {
      buffer[--i] = '0' + n % 10;
      n /= 10;
  } while(n > 0);

  str result = malloc(5 - i); 
  memcpy(result, buffer[0].ptr + i, 5 - i);
  return result;
}

/**
 * real to string
 */
function rtos(real src) str {

}

/**
 * string to int
 */
function stoi(str src) int {

}

/**
 * string to nat
 */
function ston(str src) nat {

}

/**
 * string to real
 */
function stor(str src) real {

}