/tscalc

Primary LanguageTypeScript

TypeScript Calculator

Build Status Test Coverage

Demo (https://jomcode.github.io/tscalc/)

calculator:: input * state -> state

States

ZeroState

Input Result Next State
Zero Nothing. ZeroState
NonZeroDigit Append digit to new accumulator. AccumulatorState
Operation If pending op, calculate and create next pending from input. Else create pending op. ComputedState
Equals Compute from pending op. No resulting pending ops created. ComputedState
Clear Nothing. ZeroState

AccumulatorState

Input Result Next State
Zero Append zero to accumulator. AccumulatorState
NonZeroDigit Append digit to accumulator. AccumulatorState
Operation If pending op, update display with OperationResult. If successful, create pending op. ComputedState
Equals Compute from pending op. No resulting pending ops created. ComputedState
Clear Clear any pending and go to ZeroState. ZeroState

ComputedState

Input Result Next State
Zero Go to ZeroState with current pending op if exists. ZeroState
NonZeroDigit Append digit to new accumulator. Keep pending op if exists. AccumulatorState
Operation Replace any pending op with new one from input. ComputedState
Equals Clear pending op. ComputedState
Clear Clear any pending and go to ZeroState. ZeroState

ErrorState

Input Result Next State
All Except Clear Nothing. ErrorState
Clear Clear any pending and go to ZeroState. ZeroState

TODO

  • generic tests corrections
  • ng2 tests
  • Either tests
  • make tests more descriptive
  • refactor tests to be less brittle
  • decimal?
  • negate?
  • square rt?