private DesignatorNode ParseMemberAccess(SymTable symTable, DesignatorNode record)
{
while (true)
{
if (Current.SubType != Dot)
{
return(record);
}
Next();
var rt = (RecordTypeSymbol)record.Type;
var c = Current;
Require(Identifier);
if (!rt.Fields.Contains(c.Value.ToString()))
{
throw new ParserException("Illegal identifier", c.Line, c.Position);
}
var f = new MemberAccessOperator(new List <Node> {
record, new IdentNode(null, c)
}, "Member access",
c.Line, c.Position)
{
Type = ((VarSymbol)rt.Fields[c.Value.ToString()]).Type
};
switch (f.Type)
{
case RecordTypeSymbol _:
record = f;
continue;
case ArrayTypeSymbol _:
return(ParseIndex(symTable, f));
}
return(f);
}
}
private DesignatorNode ParseIndex(SymTable symTable, DesignatorNode array)
{
while (true)
{
if (Current.SubType != LBracket)
{
return(array);
}
var ars = (ArrayTypeSymbol)array.Type;
var p = ParseIndexParam(symTable);
CheckImplicitTypeCompatibility((TypeSymbol)p.Type, TypeSymbol.IntTypeSymbol);
var i = new IndexOperator(new List <Node> {
array, p
}, "Index", p.Line, p.Position)
{
Type = ars.ElementType
};
switch (ars.ElementType)
{
case RecordTypeSymbol _:
return(ParseMemberAccess(symTable, i));
case ArrayTypeSymbol _:
array = i;
continue;
}
return(i);
}
}
private DesignatorNode ParseProcedureCall(SymTable symTable, DesignatorNode procedure)
{
var ps = (ProcedureSymbol)procedure.Type;
var p = ParseActualParameters(symTable);
CheckParameters(ps.Parameters, p);
return(new CallOperator(p.Childs, "Call", p.Line, p.Position)
{
Subprogram = ps
});
}
private DesignatorNode ParseFunctionCall(SymTable symTable, DesignatorNode function)
{
var fs = (FunctionSymbol)function.Type;
var p = ParseActualParameters(symTable);
CheckParameters(fs.Parameters, p);
var f = new CallOperator(p.Childs, "Call", p.Line, p.Position)
{
Subprogram = fs,
Type = fs.ReturnType
};
switch (fs.ReturnType)
{
case RecordTypeSymbol _:
return(ParseMemberAccess(symTable, f));
case ArrayTypeSymbol _:
return(ParseIndex(symTable, f));
}
return(f);
}
private DesignatorNode ParseCast(SymTable symTable, DesignatorNode type)
{
var ts = (TypeSymbol)type.Type;
var p = ParseCastParam(symTable);
CheckExplicitTypeCompatibility((TypeSymbol)p.Type, ts);
var c = new CastOperator(new List <Node> {
p
}, "Cast", p.Line, p.Position)
{
Type = ts
};
switch (ts)
{
case RecordTypeSymbol _:
return(ParseMemberAccess(symTable, c));
case ArrayTypeSymbol _:
return(ParseIndex(symTable, c));
}
return(c);
}
