Patent ID: 8032868

Claim:
An article of manufacture, comprising a non-transitory data storage medium tangibly embodying a program of machine readable instructions executable by an electronic processing apparatus to perform method steps for operating an electronic processing apparatus, said method steps comprising the steps of: (a) initiating a user interface to exchange data input/output with a user and an electronic processing apparatus; (b) requesting and receiving a trigger expression from a user, said trigger expression representing a non-executable data value having a state; (c) requesting and receiving a program identification of a program in which the trigger expression is to be traced, said trigger expression resulting in an L value during the execution of said program; (d) causing the electronic processing apparatus to execute the identified program; (e) monitoring execution of the identified program without altering a logic flow of execution of said program to detect occurrences of a plurality of references to a location in memory representing a state of said trigger expression, wherein each said occurrence of a reference to a location in memory representing a state of said trigger expression occurs as a result of executing the identified program; (f) responsive to each detected occurrence of a reference to said location in memory representing a state of said trigger expression, storing the respective state of the trigger expression at the time of the respective detected occurrence of a reference to said location in memory presenting a state of the trigger expression to create a corresponding respective snapshot, said snapshots forming a history of said trigger expression during execution of the identified program, said storing step being performed without interrupting or otherwise stopping execution of the identified program; (g) maintaining the capability to restore each snapshot and display each snapshot to the user.