shared_ptr<Expression> Parser::parseExpression()
{
auto rootExp = parseExpression1();
it++;
while (it->tag == OR || it->tag == AND)
{
auto opExp = make_shared<Expression>();
opExp->addNode(rootExp);
opExp->value = *it;
it++;
opExp->addNode(parseExpression1());
rootExp = opExp;
}
return rootExp;
}
static struct expr* parseExpression(ParserObjectRecordT* curSeq)
{
return parseExpression1(1,1,curSeq);
}
static struct expr* parseExpression1(int priority, int isFirst,
ParserObjectRecordT* curSeq)
{
struct expr *res, *op;
ParserObjectT* varObj;
ParserObjectRecordWithDataT tmp;
char ch;
if (priority > priorityNumber) {
switch (curToken->type) {
case ttIdentifier:
res = AllocateBuffer(sizeof(struct expr));
res->op1 = res->op2 = 0; res->opCode = 0;
res->varName = AllocateBuffer(strlen(curToken->str) + 1);
strcpy(res->varName, curToken->str);
tmp.pointerToData = 0; tmp.recPart = curSeq;
varObj = ParserFindObject(res->varName, tmp, 1).objPart;
if (!varObj) genParseError(E_UNKNOWN_OBJECT);
if (!ParserIsErrorRaised() && varObj->objKind != PARSER_OBJECT_KIND_INTEGER) genParseError(E_INTEGER_OBJECT_EXPECTED);
if (ParserIsErrorRaised()) {exprDestructor(res); return 0;}
moveToNextToken();
if (ParserIsErrorRaised()) {exprDestructor(res); return 0;}
return res;
case ttInteger:
res = AllocateBuffer(sizeof(struct expr));
res->op1 = res->op2 = 0; res->opCode = 0; res->varName = 0;
res->intConst = curToken->value;
moveToNextToken();
if (ParserIsErrorRaised()) {exprDestructor(res); return 0;}
return res;
case ttDelim:
if (curToken->value == '(') {
moveToNextToken();
res = parseExpression1(1, 1, curSeq);
if (res && !chkCurToken(')')) {
genParseError(E_RB_EXPECTED);
exprDestructor(res);
return NULL;
}
moveToNextToken();
return res;
}
// don't need "break" here
default:
return NULL;
}
} else {
op = parseExpression1(priority + 1, 1, curSeq);
if (ParserIsErrorRaised()) {exprDestructor(op); return NULL;}
if (!op) {
if (priority == getOpPriority('+') && isFirst &&
(chkCurToken('+') || chkCurToken('-'))) { // unary operations
op = AllocateBuffer(sizeof(struct expr));
op->op1 = op->op2 = 0; op->opCode = 0; op->varName = 0;
op->intConst = 0;
} else {
if (priority == getOpPriority('+')) {
genParseError(E_OPERAND_EXPECTED);
}
return NULL;
}
}
if (chkCurToken('^')) {
if (priority < getOpPriority('^')) {
genParseError(B_UNEXPECTED_CAP);
exprDestructor(op);
return NULL;
}
res = AllocateBuffer(sizeof(struct expr));
res->op1 = op; res->opCode = '^';
res->varName = 0; res->intConst = 0;
moveToNextToken();
res->op2 = parseExpression1(priority, 0, curSeq);
if (!res->op2) {exprDestructor(res->op2); return NULL;}
op = res;
} else {
while ((chkCurToken('+') || chkCurToken('-') ||
chkCurToken('*') || chkCurToken('/')) &&
getOpPriority((int)curToken->value) == priority) {
ch = (char)curToken->value;
res = AllocateBuffer(sizeof(struct expr));
res->op1 = op; res->opCode = ch;
res->varName = 0; res->intConst = 0;
moveToNextToken();
res->op2 = parseExpression1(priority, 0, curSeq);
if (!res->op2) {exprDestructor(res); return NULL;}
op = res;
}
}
if (ParserIsErrorRaised()) {exprDestructor(op); return NULL;}
return op;
}
}
