/// <summary>
/// The logic of this method is obvious...
/// Evaluate the Left and Right Expression...
/// Query the Type of the expressions and perform
/// appropriate action
/// </summary>
/// <param name="cont"></param>
/// <returns></returns>
public override SYMBOL_INFO Evaluate(RUNTIME_CONTEXT cont)
{
SYMBOL_INFO eval_left = ex1.Evaluate(cont);
SYMBOL_INFO eval_right = ex2.Evaluate(cont);
SYMBOL_INFO ret_val = new SYMBOL_INFO();
if (eval_left.Type == TYPE_INFO.TYPE_NUMERIC &&
eval_right.Type == TYPE_INFO.TYPE_NUMERIC)
{
ret_val.Type = TYPE_INFO.TYPE_BOOL;
ret_val.SymbolName = "";
if (m_op == RELATION_OPERATOR.TOK_EQ)
{
ret_val.bol_val = eval_left.dbl_val == eval_right.dbl_val;
}
else if (m_op == RELATION_OPERATOR.TOK_NEQ)
{
ret_val.bol_val = eval_left.dbl_val != eval_right.dbl_val;
}
else if (m_op == RELATION_OPERATOR.TOK_GT)
{
ret_val.bol_val = eval_left.dbl_val > eval_right.dbl_val;
}
else if (m_op == RELATION_OPERATOR.TOK_GTE)
{
ret_val.bol_val = eval_left.dbl_val >= eval_right.dbl_val;
}
else if (m_op == RELATION_OPERATOR.TOK_LTE)
{
ret_val.bol_val = eval_left.dbl_val <= eval_right.dbl_val;
}
else if (m_op == RELATION_OPERATOR.TOK_LT)
{
ret_val.bol_val = eval_left.dbl_val < eval_right.dbl_val;
}
return(ret_val);
}
else if (eval_left.Type == TYPE_INFO.TYPE_STRING &&
eval_right.Type == TYPE_INFO.TYPE_STRING)
{
ret_val.Type = TYPE_INFO.TYPE_BOOL;
ret_val.SymbolName = "";
if (m_op == RELATION_OPERATOR.TOK_EQ)
{
ret_val.bol_val = (String.Compare(
eval_left.str_val,
eval_right.str_val) == 0) ? true:false;
}
else if (m_op == RELATION_OPERATOR.TOK_NEQ)
{
ret_val.bol_val = String.Compare(
eval_left.str_val,
eval_right.str_val) != 0;
}
else
{
ret_val.bol_val = false;
}
return(ret_val);
}
if (eval_left.Type == TYPE_INFO.TYPE_BOOL &&
eval_right.Type == TYPE_INFO.TYPE_BOOL)
{
ret_val.Type = TYPE_INFO.TYPE_BOOL;
ret_val.SymbolName = "";
if (m_op == RELATION_OPERATOR.TOK_EQ)
{
ret_val.bol_val = eval_left.bol_val == eval_right.bol_val;
}
else if (m_op == RELATION_OPERATOR.TOK_NEQ)
{
ret_val.bol_val = eval_left.bol_val != eval_right.bol_val;
}
else
{
ret_val.bol_val = false;
}
return(ret_val);
}
return(null);
}
/// <summary>
///
/// </summary>
/// <param name="cont"></param>
/// <returns></returns>
public override SYMBOL_INFO Execute(RUNTIME_CONTEXT cont)
{
inf = (m_e1 == null) ? null : m_e1.Evaluate(cont);
return(inf);
}
TYPE_INFO _type; // Type
/// <summary>
/// this Ctor just stores the variable name
/// </summary>
/// <param name="inf"></param>
public Variable(SYMBOL_INFO inf)
{
m_name = inf.SymbolName;
}
/// <summary>
///
/// </summary>
/// <param name="inf"></param>
public VariableDeclStatement(SYMBOL_INFO inf)
{
m_inf = inf;
}