private ExpressionNode ParseTerm(SymTable symTable)
{
var f = ParseFactor(symTable);
var c = Current;
while (MulOps.Contains(c.SubType))
{
Next();
var t = ParseFactor(symTable);
if (
t.Type is ArrayTypeSymbol || t.Type is RecordTypeSymbol ||
f.Type is ArrayTypeSymbol || f.Type is RecordTypeSymbol
)
{
throw new ParserException("Incompatible types", c.Line, c.Position);
}
if (c.SubType == Slash)
{
f = ToType(f, TypeSymbol.RealTypeSymbol);
}
(f, t) = SelectType(f, t);
f = new BinOpNode(new List <Node> {
f, t
}, c.SubType, c.Line, c.Position)
{
Type = f.Type
};
c = Current;
}
return(f);
}
private ExpressionNode ParseExpression(SymTable symTable)
{
var e = ParseSimpleExpression(symTable);
var c = Current;
while (RelOps.Contains(c.SubType))
{
Next();
var t = ParseSimpleExpression(symTable);
if (
t.Type is ArrayTypeSymbol || t.Type is RecordTypeSymbol ||
e.Type is ArrayTypeSymbol || e.Type is RecordTypeSymbol
)
{
throw new ParserException("Incompatible types", c.Line, c.Position);
}
(e, t) = SelectType(e, t);
e = new BinOpNode(new List <Node> {
e, t
}, c.SubType, c.Line, c.Position)
{
Type = TypeSymbol.IntTypeSymbol
};
c = Current;
}
return(e);
}
private ExpressionNode ParseSimpleExpression(SymTable symTable)
{
if (Current.SubType == CharConstant)
{
var tmp = Current;
Next();
return(new ConstNode(null, tmp.Value, tmp.Line, tmp.Position)
{
Type = TypeSymbol.CharTypeSymbol
});
}
var t = ParseTerm(symTable);
var c = Current;
while (AddOps.Contains(c.SubType))
{
Next();
var temp = ParseTerm(symTable);
if (
t.Type is ArrayTypeSymbol || t.Type is RecordTypeSymbol ||
temp.Type is ArrayTypeSymbol || temp.Type is RecordTypeSymbol
)
{
throw new ParserException("Incompatible types", c.Line, c.Position);
}
(t, temp) = SelectType(t, temp);
t = new BinOpNode(new List <Node> {
t, temp
}, c.SubType, c.Line, c.Position)
{
Type = t.Type
};
c = Current;
}
return(t);
}
