Variable closure

A computer-based system for accessing a closure variable defined in a closure function of a computer program, the system comprising:

• a) a code instrumentation component configured to including:
• i. parsing the function and inserting program code to store a pointer to the closure variable in a data structure;
• ii. parsing a lambda function to determine one or more references to the closure variable, and inserting an instruction to access the closure variable in a runtime stack frame corresponding to an instance of the function;
• b) a first helper function that performs actions including retrieving the pointer to the closure variable, employing the pointer to locate the closure variable in the runtime stack frame, and retrieving a value from the location of the closure variable;
• and
• c) a second helper function that performs actions including storing the pointer to the program variable.

A computer-readable storage medium comprising computer program instructions for enabling a user program to access one or more closure variables stored on a runtime stack, the closure variables local to a closure function, the program instructions executable by one or more processors to perform actions including:

• a) parsing the user program to determine an entrance location of the closure function;
• b) inserting program code into the user program closure function to store a pointer to each of the one or more closure variables;
• c) in response to a detection of an invocation of an instance of the closure function, storing the pointer to each of the one or more closure variables in a data structure;
• and
• d) in response to an instruction in a lambda function within the closure function for retrieval of a value stored in a closure variable on the runtime stack, retrieving the value stored in the closure variable by using the pointer to the closure variable.