Simple Dice Roll app in Swift using MVVM
This is an illustration of a viewmodel as a transform from input to output. The inspiration was the idea of a BCD (Binary Coded Decimal) to 7-element dice circuit. This circuit can map the numbers 1-6 to their patterns in 'dice' format, using only an AND gate and an OR gate.
The dice format is as follows:
A D
B X E
C F
Where the numbers 1-6 are represented by:
. . 2 . 3 . 4 4 5 5 6 6
. 1 . . . . . 3 . . . . . 5 . 6 . 6
. . . 2 . 3 4 4 5 5 6 6
The 'pins' of the dice layout map to the inputs (i1, i2, i4 in binary) as follows:
A = F = i2 OR i4
B = E = i2 AND i4
C = D = i4
X = i1
The code encapsulates this logic in the ViewModel inside a reactive mapping. The drivers for each of the 4 output pins bind to views in ViewController, and drive their isHidden property.
The dice roller returns an Observable which cycles through random numbers (1-6) and lands on the final number, then completes.
You must first run pod install before opening the xcworkspace file