♻️ Rewrite ADI Pneumatics class

[Jerrylum]

Summary:

The current design is too complex and buggy. Below is a list of identified anomalies in the Pneumatics class:

Anomaly Category:
Missing, Extraneous, Ambiguous, Inconsistent, Wrong (incorrect fact), Typos (or editorial), Others

Assume get_state get the physical state of the pneumatics

For P = Pneumatics(bool start_extended, bool active_low = false)

# P(false, false)
    extend() -> s = true;
    retract() -> s = true; [W1] should be false
    toggle() -> s = !s;
    get_state() -> false ? state : !state;
                                      ^used
        [W2] if extend() is used, state should be true and the function returns false
             but it is expected to return true as the physical state is true

# P(false, true)
    extend() -> s = false;
    retract() -> s = false; [W3] should be true
    toggle() -> s = !s;
    get_state() -> true ? state : !state;
                            ^used
        [W4] if extend() is used, state should be false and the function returns false
             but it is expected to return true as the physical state is true

# P(true, false)
    extend() -> s = true;
    retract() -> s = true; [W5] should be false
    toggle() -> s = !s;
    get_state() -> false ? state : !state;
                                      ^used
        [W6] if extend() is used, state should be true and the function returns false
             but it is expected to return true as the physical state is true
    
# P(true, true)
    [W7] if extend() is used, state should be false, and it is expected to extend the pneumatics physically
         start_extended is also expected to extend the pneumatics physically when the constructor is called
         but if start_extended set to true, the state also set to true 
    extend() -> s = false;
    retract() -> s = false; [W8] should be true
    toggle() -> s = !s;
    get_state() -> true ? state : !state;
                            ^used
        [W9] if extend() is used, state should be false and the function returns false
             but it is expected to return true as the physical state is true

[A10] state, get_state: is it physical state of the pneumatics or logical state of the pneumatics, what happen if active_low is set to true?
[I11] state and active_low inconsistent if two pneumatics classes defined using the same ADI port

To improve the current design, active_low has been removed and the implementation of some methods has been rewritten.

References (optional):

Bug Report on the PROS Beta Testers Server

[Richard-Stump]

I have updated the implementation to keep the active_low feature. This should hopefully fix the logical error that existed in the original implementation.

Working through the rewritten code, this is the result I got:

	state = false ^ false = false

	extend(): 	state = true
	retract(): 	state = false
	toggle(): 	state = true
	
	is_extended(): returns state ^ extended_is_low = false

p(start_extended = true, extended_is_low = false):
	state = true ^ false = true
	
	extend():	state = true
	retract(): 	state = false
	toggle(): 	state = false
	
	is_extended(): returns state ^ extended_is_low = true
		
p(start_extended = false, extended_is_low = true):
	state = false ^ true = true

	extend(): 	state = false
	retract(): 	state = true
	toggle(): 	state = false
	
	is_extended(): returns state ^ extended_is_low = false
	
p(start_extended = true, extended_is_low = true):
	state = true ^ true = false

	extend(): 	state = false
	retract(): 	state = true
	toggle(): 	state = true
	
	is_extended(): returns state ^ extended_is_low = true

The member function get_state() was renamed to is_extended() to better reflect the fact that it returns the logical state of the pneumatics, not the physical state of the ADI port.

The extend() and retract() functions now return 1 if they are newly extended/retracted, or 0 if they were already in the requested position.

The documentation was also updated to reflect the changes.

[noam987]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[noam987]

Logic Looks good to me and maintains Active low functionality