Hi Sergey,
------------
What speed has to do with property been read-only? It's your choice how to implement it.
In VFP, if one characteristic is implemented inner (written in C++ by VFPT),
this (if done good) is medium 10 times faster of the same one if it comes implemented with the VFP language.
Because, hidden, protected ( and readonly ) they are base attributes,
would be preferibile that were implement to you from the system.
In-fact on VFP, protected readonly attribute for a property exist:
x=CREATEOBJECT('textbox')
x.Parent = _screen
but it is not developed like characteristic of the interpreted language.
Fabio