RTTI Delphi Create as TValue an n-dimensional matrix - delphi

Question

Good day,
TValue is a Delphi-2010 and up RTTI feature.
Following on from my earlier question, I had tried to make recurrent function to return a TValue as a n-dimensional. matrix(2D, 3D, 4D...)
for example, this procedure will show a n-dimensional matrix(it will list all elements from a n-dimensional matrix as TValue variable):
Procedure Show(X:TValue);
var i:integer;
begin
if x.IsArray then
begin
for i:=0 to x.GetArrayLength-1 do
show(x.GetArrayElement(i));
writeln;
end else
write(x.ToString,' ');
end;
I don't understand how to create a function to create from a TValue an n-dimensional matrix. For example i need a Function CreateDynArray(Dimensions:array of integer; Kind:TTypeKind):TValue; and the function will return a TValue which is a dynamic array how contain the dimenssions for example:
Return=CreateDynArray([2,3],tkInteger); will return a TValue as tkDynArray
and if i will show(Return) will list
0 0 0
0 0 0
Is not terminated.
From a TValue i try to create a DynArray with n-dimensions
Procedure CreateArray(var Value:TValue; NewDimmension:integer; NewValue2Kind:TTypeKind; NewValue2:TValue; IsLast:Boolean);
var i:integer;
NewValue:TValue;
len:Longint;
begin
If Value.IsArray then// we have components in this dimension
begin
for i:=0 to Value.GetArrayLength-1 do// list all
begin
NewValue:=Value.GetArrayElement[i];
CreateArray(newValue,NewDimension,NewValue2Kind,NewValue2,IsLast);
Value.SetArrayElement(i,NewValue);
end;
end;
end else
begin
if isLast then
begin
len:=NewDimension;
DynArraySetLength(PPointer(Value.GetRefereneToRawData)^,Value.TypeInfo,1,#len); //set length to NewDimension
for i:=0 to NewDimension-1 do //Fill all with 0
Value.SetArrayElement(i,NewValue2);
end else
begin
len:=NewDimension;
DynArraySetLength(PPointer(Value.GetRefereneToRawData)^,Value.TypeInfo,1,#len);//I will create len TValues
end;
end;
var Index:array of integer;
Value:TValue;
ValuKind:TTypeKind;
......
......
....
Case token of
tokInt:
begin
ValueKind:=tkInteger;
Value:=0;
end;
.....
end;
Index:=GetIndexFromSintacticTree;//for example if i have int[20][30] index=[20,30]
for i:=0 to high(index) do
begin
if i = high(index) then CreateArray(Variable.Value,Index[i],ValueKind,Value,True)
else CreateArray(Variable.Value,Index[i],ValueKind,Value,False)
//Variable.Value is TValue
end;
//first TValue have 1 element, after that it will have 20 elements, and after that will have 20*30 elements
Thank you very much, and have a nice day!

Answer 1

To create a dynamic array dynamically, you need a reference to its type info structure (PTypeInfo) to pass to DynArraySetLength; calling DynArraySetLength and passing a reference to a nil pointer is how you can create a new dynamic array. If the specific shape of dynamic array does not already exist in your Delphi program, there will be no specific PTypeInfo pointer that the compiler will generate for you. In this case, you would have to generate the corresponding PTypeInfo data structure yourself. This is possible, though tedious.
Frankly, I'd recommend you use a different structure than built-in Delphi dynamic arrays to represent arrays in your scripting language-like problem. In the long run it will probably be a lot less work than trying to dynamically generate the low-level RTTI data, which is more likely to change from version to version now that it has a much higher level abstraction in the Rtti unit.