SymbolListPtr CodeBlock::convert_postfix(SymbolListPtr p) {
// data structs
unique_ptr<stack<SymbolPtr>> op_stack = unique_ptr<stack<SymbolPtr>>(new stack<SymbolPtr>);
SymbolListPtr unpostfix_symbols = SymbolListPtr(new SymbolList());
// shunting yard (modified for unary operators!)
for (auto i = p->begin(); i !=
p->end(); i++) {
if (is_operand(*i)) {
unpostfix_symbols->push_back(*i);
if (!op_stack->empty()) {
if (is_unary(op_stack->top())) {
unpostfix_symbols->push_back(op_stack->top());
op_stack->pop();
}
}
} else if (is_operator(*i)) {
if (is_unary((*i))) {
op_stack->push(*i);
} else {
while (!op_stack->empty()
&& !is_lparen(op_stack->top())
&& compare_ops(*i, op_stack->top()) <= 0) {
unpostfix_symbols->push_back(op_stack->top());
op_stack->pop();
}
op_stack->push(*i);
}
} else if (is_lparen(*i)) {
op_stack->push(*i);
} else if (is_rparen(*i)) {
while (!op_stack->empty()) {
if (is_lparen(op_stack->top())) {
op_stack->pop();
if (!op_stack->empty()) {
if (is_unary(op_stack->top())) {
unpostfix_symbols->push_back(op_stack->top());
op_stack->pop();
}
}
break;
}
unpostfix_symbols->push_back(op_stack->top());
op_stack->pop();
}
}
}
while(!op_stack->empty()) {
unpostfix_symbols->push_back(op_stack->top());
op_stack->pop();
}
// set the temp symbols as the postfix stuff
return unpostfix_symbols;
}
void infix2rpn(char *expr, RPNEntry ***rpne, int *nrpne) {
Array *rpn = array_new(32, 16);
Stack *stack_ops = stack_new(16);
//static char token[64];
char *token;
int tokenlen;
int i;
int uminus = 1;
int inoperand = 0;
//printf("%s:-> ", expr);
char lookahead;
for(token = gettoken(expr, &tokenlen, &lookahead);token != NULL; token = gettoken(NULL, &tokenlen, &lookahead)) {
if (uminus) {
if (*token == T_MINUS) {
*token = T_UMINUS;
}
uminus = 0;
}
if (is_function(token, tokenlen)) {
stack_push(stack_ops, token);
} else if (is_operand(token)) {
array_add(rpn, token);
} else if (is_arg_separator(token)) {
while(!stack_empty(stack_ops) && !is_lparen(stack_peek(stack_ops))) {
array_add(rpn, stack_pop(stack_ops));
}
} else if (is_operator(token)) {
uminus = 1;
if (stack_empty(stack_ops)) {
stack_push(stack_ops, token);
} else {
if (compare_ops(token, stack_peek(stack_ops))) {
array_add(rpn, stack_pop(stack_ops));
}
stack_push(stack_ops, token);
}
} else if (is_lparen(token)) {
uminus = 1;
stack_push(stack_ops, token);
} else if (is_rparen(token)) {
while(!stack_empty(stack_ops) && !is_lparen(stack_peek(stack_ops))) {
array_add(rpn, stack_pop(stack_ops));
}
stack_pop(stack_ops);
} else {
// errorski
}
}
while (!stack_empty(stack_ops)) {
array_add(rpn, stack_pop(stack_ops));
}
stack_free(&stack_ops);
*rpne = (RPNEntry **)malloc(rpn->count * sizeof(RPNEntry*));
for (i = 0; i < rpn->count; i++) {
token = array_get(rpn, i);
(*rpne)[i] = new_rpnentry(token, strlen(token));
}
*nrpne = rpn->count;
array_free(&rpn);
}
