https://github.com/tommay/clock_equations

Figure out the simple equations that can be made from the time on a digital clock
https://github.com/tommay/clock_equations

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Figure out the simple equations that can be made from the time on a digital clock

• Host: GitHub
• URL: https://github.com/tommay/clock_equations
• Owner: tommay
• License: mit
• Created: 2014-11-09T21:44:22.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2015-02-26T06:40:09.000Z (over 9 years ago)
• Last Synced: 2023-04-19T16:52:47.917Z (over 1 year ago)
• Language: Ruby
• Homepage:
• Size: 305 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
clock_equations

===============

Figure out the simple equations that can be made from the time on a digital clock

My 9-year old daughter Chloe and I like to look at the digital clock

sometimes and make equations out of the numbers.  For example,

12:02 could be 1*2+0 = 2, and 12:03 could be 1+2 = 0+3.

I thought it would be fun to code up a program to find all the "clock

eauations".  There are two parts: generating the equations, and

evaluating their truth value.  Generating the equations done one

of two ways:

- clock.rb uses a sequence of `.lazy` enumerators to generate the times,

build all possible equations from the numbers of each tine, and filter

the valid equations.

- enum_clock.rb uses explicit enumerators of various kinds, mostly to see

how things weould come out if I coded them up;

    


       
Enumerator

       
Standard Ruby Enumerator

       
FiberEnumerator

       
Enumerator using Fiber (fiber_enumerator.rb).  This is

           straightforward.




       
CallccEnumerator

       
Enumerator using bare callcc (callcc_enumerator.rb).  This one

           is not particularly nice or well-done.

       
CoroutineEnumerator

       
Enumerator that encapsulates the callcc usage into a

           Coroutine class.  This one is pretty good.

           (coroutine_enumerator.rb, coroutine.rb)

    

    The `Enumerator` class can be set by editing enum_clock.rb and setting

    variable `UseEnumerator` to the proper class (ugh).


The equations' truth values are determined using a recursive descent

expression evaluator.