source: trunk/tools/porting/src/rppexpressionbuilder.cpp@ 5

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#include "rppexpressionbuilder.h"
#include "tokens.h"
#include "rpp.h"

QT_BEGIN_NAMESPACE

using namespace TokenEngine;
namespace Rpp {

ExpressionBuilder::ExpressionBuilder(const TokenList &tokenList, const QVector<Type> &typeList, TypedPool<Item> *memoryPool)
:i(0)
,m_tokenList(tokenList)
,m_typeList(typeList)
,m_memoryPool(memoryPool)
{}

Rpp::Expression *ExpressionBuilder::parse()
{
    if(unary_expression_lookup())
        return conditional_expression();
    else
        return createIntLiteral(0);
}
Type ExpressionBuilder::next()
{
    if(!hasNext())
        return Token_eof;
    return typeAt(i++);
}

inline bool ExpressionBuilder::test(int token)
{
    if (i < m_tokenList.count() && typeAt(i) == token) {
        ++i;
        return true;
    }
    return false;
}

inline bool ExpressionBuilder::moreTokens(int delta)
{
    return (i + delta < m_tokenList.count());
}

inline Type ExpressionBuilder::lookup(int k)
{
    const int l = i - 1 + k;
    return l < m_tokenList.count() ? typeAt(l) : Token_eof;
}

Expression *ExpressionBuilder::conditional_expression()
{
    Expression *value = logical_OR_expression();
    if (test('?')) {
        Expression *leftExpression = conditional_expression();
        Expression *rightExpression;
        if(test(':'))
            rightExpression = conditional_expression();
        else
            rightExpression = createIntLiteral(0);
        return createConditionalExpression(value, leftExpression, rightExpression);
    }
    return value;
}

Expression *ExpressionBuilder::logical_OR_expression()
{
    Expression *value = logical_AND_expression();
    if (test(Token_or))
        return createBinaryExpression(Expression::OrOp, value, logical_OR_expression());
    return value;
}

Expression *ExpressionBuilder::logical_AND_expression()
{
    Expression *value = inclusive_OR_expression();
    if (test(Token_and))
        return createBinaryExpression(Expression::AndOp, value, logical_AND_expression());
    return value;
}

Expression *ExpressionBuilder::inclusive_OR_expression()
{
    Expression *value = exclusive_OR_expression();
    if (test('|'))
        return createBinaryExpression('|', value, inclusive_OR_expression());
    return value;
}