Improved contracts

src/ee.c

@@ -3,8 +3,13 @@ int error = 0;
 void printStack(STACK);
 
 int
-main (const int argc, const char* argv[])
-{
+main (const int argc, const char* argv[]) {
+    /* if argv is an array of strings corresponding to a well-formed RPN
+     * expression, then main prints the value of the expression and returns 0
+     * otherwise, main will return one of ERR_NO_EXPR, ERR_INVALID_INPUT, 
+     * ERR_NS_OPERANDS, or ERR_NS_OPERATORS, as defined in ee.h, depending
+     * on the type of malformed expression.
+     */
 
     STACK expr = NULL;
 
@@ -58,9 +63,7 @@ int
 isNum(const char* query)
 {
 
-    /*
-     * If query is a string, isNum(query) iff query represents a number.
-     */
+    // If query is a string, isNum(query) iff query represents a number.
 
     char *extra_char;
     strtod(query, &extra_char);
@@ -90,6 +93,10 @@ arrity(const char query)
 bool
 isDivByZero(double *_operands)
 {
+    /* if _operands represents an array of operands, isDivByZero(_operands)
+     * iff the first operand (corresponding to the divisor) is zero
+     */
+     
     return _operands[0] == 0;
 }