int IndexReader::getNextTerm(const char * fieldName, uint64_t &termSign)
{
if (unlikely( NULL == fieldName )) return -1;
uint64_t fieldSign = idx_sign64( fieldName, strlen(fieldName) );
return getNextTerm( fieldSign, termSign );
}
float DexCalc::eval(std::string expr)
{
int i;
std::string result;
std::string newExpr, token, prevToken;
std::stack<std::string> opStack, elemStack, inStack;
int depth;
newExpr = "(" + expr + ")";
if (!mTurbo)
newExpr = TS_Util::fixExpr(newExpr);
newExpr = replaceEx(newExpr, "E", "*10^");
// STEP #1 (GROUP)
// group tokens into operators and operands
// (check for syntax errors)
//
// "(1 * 2 + 3)"
//
// [O]: ( * + )
// [E]: 1 2 3
// [I]:
token = "";
depth = 0;
i = 0;
while (i < newExpr.length())
{
prevToken = token;
//==============================
token = getNextTerm(newExpr, i);
//==============================
depth += (token == "(") ? 1 : 0;
depth -= (token == ")") ? 1 : 0;
if (depth < 0)
throw Exception("expected end of statement");
#ifndef TURBO_MODE
if (TS_Util::rankOp(prevToken[0]) > 0 || prevToken == "(")
{
if (token == "+")
{
token = prevToken;
continue;
}
if (token == "-") token = "neg";
if (token == "!") token = "not";
if (token == "~") token = "bnot";
std::string prefix = left(token, 2);
std::string value = lcase(right(token, token.length() - 2));
if (prefix == "0x")
token = changeBase(value, 16, 10);
if (prefix == "0o")
token = changeBase(value, 8, 10);
if (prefix == "0b")
token = changeBase(value, 2, 10);
}
if (
TS_Util::rankOp(prevToken[0]) && (token[0] == OP_INC || token[0] == OP_DEC) ||
(prevToken[0] == OP_INC || prevToken[0] == OP_DEC) && TS_Util::rankOp(token[0])
)
elemStack.push("0");
else if (TS_Util::isFunc(prevToken) && token != "@" && token != ")")
opStack.push("@");
else
TS_Util::checkSyntaxError(prevToken, token);
#endif
//=================================
if (TS_Util::rankOp(token[0]))
opStack.push(token);
else
elemStack.push(token);
//=================================
}
if (depth > 0)
throw Exception("expected close paren");
// force operator into inStack
// (start chain reaction)
//
// "(1 * 2 + 3)"
//
// [O]: ( * +
// [E]: 1 2 3
// [I]: )
inStack.push(opStack.top());
opStack.pop();
while (!inStack.empty())
{
// STEP #2 (LOAD)
// load inStack with opStack, elemStack elements
// (stop at appropriate point)
//
// "(1 * 2 + 3)"
//
// [O]: (
// [E]: 1
// [I]: ) 3 + 2 *
while
(
(opStack.top()[0] == OP_SET && TS_Util::rankOp(opStack.top()[0]) > TS_Util::rankOp(inStack.top()[0])) ||
(opStack.top()[0] != OP_SET && TS_Util::rankOp(opStack.top()[0]) >= TS_Util::rankOp(inStack.top()[0])) ||
opStack.top() == ")"
)
{
// transfer close-parens to inStack
// (if any)
while (opStack.top() == ")")
{
inStack.push(opStack.top());
opStack.pop();
}
// transfer operand to inStack
inStack.push(elemStack.top());
elemStack.pop();
// force operator into inStack
// (continue chain reaction)
if (opStack.top() != "(")
{
inStack.push(opStack.top());
opStack.pop();
}
}
// STEP #3 (BIND)
// bind elemStack, inStack operands with an opStack operator
// (push result into elemStack)
//
// "(1 * 2 + 3)"
//
// [O]: ( *
// [E]: 1
// [I]: ) 3 + 2
//
// [O]: ( +
// [E]: 2
// [I]: ) 3
//
// [O]: (
// [E]: 5
// [I]: )
//
// [O]:
// [E]: 5
// [I]:
while (TS_Util::rankOp(opStack.top()[0]) <= TS_Util::rankOp(inStack.top()[0]))
{
if (TS_Util::rankOp(inStack.top()[0]))
{
//======================================================
opStack.push(inStack.top());
inStack.pop();
float temp =
this->bind(
elemStack.top(), opStack.top()[0], inStack.top()
);
result = (fabs(temp) == HUGE_VAL) ? "0" : cstr(temp);
opStack.pop();
elemStack.pop();
//======================================================
}
else
result = inStack.top();
//============
inStack.pop();
//============
while (!opStack.empty() && opStack.top() == "(" && inStack.top() == ")")
{
opStack.pop();
inStack.pop();
}
if (inStack.empty())
{
if (isNumeric(result))
return val(result);
else
return this->getVar(result);
}
else
elemStack.push(result);
}
}
throw Exception("unknown error");
}