static NODE * factor(void){
NODE * t = NULL;
switch(token.type){
case NUM:
t = new_exp(N_CONST);
if ((t != NULL) && (token.type == NUM)){
t->attribute.val = token.attribute.val;
}
match(NUM);
break;
case VAR:
t = new_exp(N_VAR);
if ((t != NULL) && (token.type == VAR)){
t->attribute.val = toHeap(token.attribute.name);
}
match(VAR);
break;
case LPAR:
match(LPAR);
t = exp();
match(RPAR);
break;
default:
syntax_error("Unexpected Token -> ");
token = getToken();
break;
}
return t;
}
static inline struct expression *
new_exp_1(enum expression_operator op, struct expression *right) {
struct expression *args[1];
args[0] = right;
return new_exp(1, op, args);
}
static struct expression *
new_exp_2(enum expression_operator op, struct expression *left,
struct expression *right) {
struct expression *args[2];
args[0] = left;
args[1] = right;
return new_exp(2, op, args);
}
static inline struct expression *
new_exp_3(enum expression_operator op, struct expression *bexp,
struct expression *tbranch, struct expression *fbranch) {
struct expression *args[3];
args[0] = bexp;
args[1] = tbranch;
args[2] = fbranch;
return new_exp(3, op, args);
}
//TODO PRobably a problem here
static NODE * exp(void){
NODE * t = new_exp(N_OP);
if (t != NULL){
t->child[0] = exp_helper();
t->attribute.token_class = token.type;
}
match(token.type); // ADD or SUB
if (t != NULL){
t->child[1] = exp_helper();
}
}
static NODE * term(void){
NODE * t = factor();
while (token.type == MUL || token.type == DIV){
NODE * temp = new_exp(N_OP);
if (temp != NULL){
temp->child[0] = t;
temp->attribute.token_class = token.type;
t = temp;
match(token.type);
temp->child[1] = factor();
}
}
return t;
}
static NODE *exp_helper(void){
NODE * t = term();
while (token.type == ADD || token.type == SUB){
NODE * temp = new_exp(N_OP);
if (temp != NULL){
temp->child[0] = t;
temp->attribute.token_class = token.type;
t = temp;
match(token.type);
p->child[1] = term();
}
}
return t;
}
static inline struct expression *
new_exp_0(enum expression_operator op) {
return new_exp(0, op, NULL);
}
