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openmw/components/compiler/exprparser.cpp

162 lines
4.1 KiB
C++

#include "exprparser.hpp"
#include <stdexcept>
#include "generator.hpp"
#include "scanner.hpp"
#include "errorhandler.hpp"
namespace Compiler
{
char ExprParser::popUnaryOperator()
{
if (mOperators.empty())
return 0;
char op = mOperators[mOperators.size()-1];
if (op!='m') // unary -
return 0;
mOperators.resize (mOperators.size()-1);
return op;
}
char ExprParser::popOperand (std::vector<Interpreter::Type_Code>& code)
{
Operand operand = mOperands[mOperands.size()-1];
mOperands.resize (mOperands.size()-1);
if (operand.mType=='l')
Generator::pushInt (code, mLiterals, operand.mInteger);
else if (operand.mType=='f')
Generator::pushFloat (code, mLiterals, operand.mFloat);
else
throw std::logic_error ("unknown expression type");
return operand.mType;
}
ExprParser::ExprParser (ErrorHandler& errorHandler, Context& context, Locals& locals,
Literals& literals)
: Parser (errorHandler, context), mLocals (locals), mLiterals (literals),
mNextOperand (true)
{}
bool ExprParser::parseInt (int value, const TokenLoc& loc, Scanner& scanner)
{
if (mNextOperand)
{
Operand operand;
operand.mType = 'l';
operand.mInteger = value;
mOperands.push_back (operand);
mNextOperand = false;
mTokenLoc = loc;
return true;
}
return Parser::parseInt (value, loc, scanner);
}
bool ExprParser::parseFloat (float value, const TokenLoc& loc, Scanner& scanner)
{
if (mNextOperand)
{
Operand operand;
operand.mType = 'f';
operand.mFloat = value;
mOperands.push_back (operand);
mNextOperand = false;
mTokenLoc = loc;
return true;
}
return Parser::parseFloat (value, loc, scanner);
}
bool ExprParser::parseName (const std::string& name, const TokenLoc& loc,
Scanner& scanner)
{
return Parser::parseName (name, loc, scanner);
}
bool ExprParser::parseKeyword (int keyword, const TokenLoc& loc, Scanner& scanner)
{
return Parser::parseKeyword (keyword, loc, scanner);
}
bool ExprParser::parseSpecial (int code, const TokenLoc& loc, Scanner& scanner)
{
if (code==Scanner::S_comma)
{
// end marker
mTokenLoc = loc;
return false;
}
if (code==Scanner::S_newline)
{
// end marker
mTokenLoc = loc;
scanner.putbackNewline (loc);
return false;
}
if (code==Scanner::S_minus)
{
if (mNextOperand)
{
// unary
mOperators.push_back ('m');
mTokenLoc = loc;
return true;
}
}
return Parser::parseSpecial (code, loc, scanner);
}
void ExprParser::reset()
{
mOperands.clear();
mOperators.clear();
mNextOperand = true;
}
char ExprParser::write (std::vector<Interpreter::Type_Code>& code)
{
if (mOperands.empty() && mOperators.empty())
getErrorHandler().error ("missing expression", mTokenLoc);
if (mNextOperand)
getErrorHandler().error ("syntax error in expression", mTokenLoc);
char type = ' ';
while (!mOperands.empty())
{
type = popOperand (code);
while (char op = popUnaryOperator())
{
if (op=='m')
{
Generator::negate (code, type);
}
else
throw std::logic_error ("unknown unary operator");
}
}
return type;
}
}