int exp1()
{
/*
* exp1 -> MINUS term exp1
* | MINUS term exp2
* | exp2
*/
if(match(MINUS))
{
advance();
term();
if(match(MINUS))
{
advance();
term();
exp1();
printf("-\n");
}
expr_prime();
printf("-\n");
}
else
{
expr_prime();
}
}
expression()
{
/* expression -> term expression' */
term();
expr_prime();
}
expr_prime()
{
/* expression' -> PLUS term expression'
* | epsilon
*/
if( match( PLUS ) )
{
advance();
term();
expr_prime();
}
}
static boolean expr() {
if(DEBUG) {
printf("Looking for an <expr>\n");
}
if(term()) {
if(expr_prime()) {
return TRUE;
} else {
printf("<term> not followed by <expr-prime> in <expr>\n");
return FALSE;
}
} else {
printf("<term> not found in <expr>\n");
return FALSE;
}
}
static boolean expr_prime() {
if(DEBUG) {
printf("Looking for an <expr-prime>\n");
}
if(additive_op()) {
if(term()) {
if(expr_prime()) {
return TRUE;
} else {
printf("<term> not followed by <expr-prime> in <expr-prime>\n");
return FALSE;
}
} else {
printf("<additive-op> not followed by <term> in <expr-prime>\n");
return FALSE;
}
} else {
return TRUE;
}
}