Function reduce

reduce<T>(
    program: Program,
    callback: (
        accumulator: T,
        instruction: Instruction,
        index: number,
        program: Program,
    ) => T,
    initialValue: T,
): T
Folds the instruction list into a single value.
Type Parameters
- T
Parameters
- program: Program
  Program to fold.
- callback: (accumulator: T, instruction: Instruction, index: number, program: Program) => T
  Combines the accumulator with each instruction.
- initialValue: T
  Starting accumulator.
Returns T
The final accumulator.