Max Calc

iPhone iPad calculator based SwiftUI

Every real programmer writes two codes:

1. Hello Word for console application
2. Calculator for testing UI

I'm not an exception

iOS Calculator

(screenshots attached)

Features:

• Portrait (Simple) / Landscape (Math) mode / Autorotate
• Togle first line: argument or expression (Portraite / Landscape / Autorotate)
• Very Big Buttons
• 9 cells memory storage (access button 'M' then digit '1' - '9', 'M' 'M' - shows all list) with indication used cell
• All universal Math functions as root(value, base), log(value, base), pwr(value, base)
• Constants Pi and e
• Memory operations indicator
• Copy/paste result and arguments
• View tuning, setup saving in UserDefaults
• History of calculations
• History: sorting by hours and date and saving to UserDefaults (beauty conquers all)
• Extended result formatting:
  • engeneering format
  • fixed digital plases for fraction

Used:

• SwiftUI, Forms
• Router + Coordinator patters
• View Controller / Logic Separation, trying
• @EnvironmentObject / @State patterns
• Test Units, a little example
• Full FSM (Mealy machine):
  • Switch / Case implementation (a big pain (long unreadable coding, do it better!) ... in progress)
  • State in stack organisation

FSM States Tree

enum ClearSign {

case clearBefore = "clearBefore"
case continueInput = "continueInput"

}

enum MemoryOp {

case erase = "MC"
case store = "MS"
case recall = "M"
case pi = "𝛑"
case e = "e"

}

enum CalcRunState {

case error
case firstDigitEnter(ClearSign)
case secondDigitEnter(ClearSign)
case firstDigitMemory(MemoryOp)
case secondDigitMemory(MemoryOp)
case resultMemory(MemoryOp)
case memoryClear
case result

}

Inspiration:

• Designing A Calculator with FSM Logic https://rvunabandi.medium.com/making-a-calculator-in-javascript-64193ea6a492
• Finite-state machine https://en.wikipedia.org/wiki/Finite-state_machine
• Mealy machine https://en.wikipedia.org/wiki/Mealy_machine