Question

For my curiosity sake I’m looking for a dynamic object oriented language that allows you to change true to false and vice versa.

Something like this:

true = false, false = true;

This should also affect any conditional statements, therefore 42 == 42 should return False.
Basically, with this premise, nothing in the language would be safe from the programmer.

Is there any language like this?

Answer 1

Smalltalk will let you do this.

Everything in Smalltalk-80 is
available for modification from within
a running program. This means that,
for example, the IDE can be changed in
a running system without restarting
it. In some implementations, the
syntax of the language or the garbage
collection implementation can also be
changed on the fly. Even the statement
true become: false is valid in
Smalltalk, although executing it is
not recommended. When used
judiciously, this level of flexibility
allows for one of the shortest
required times for new code to enter a
production system.

http://en.wikipedia.org/wiki/Smalltalk