Using boolean logic to deal with dates

Transcript

1. 1.

   For fun Using Boolean logic to deal with dates

2. 2.

   The problem

3. 3.

   The problem Parse a string to a Date object

4. 4.

   The problem • Date could be in the mm/dd/yyyy format

5. 5.

   The problem • Date could be in the mm/dd/yyyy format

   • Date could be in any format recognisable by Date.parse
6. 6.

   The problem • Date could be in the mm/dd/yyyy format

   • Date could be in any format recognisable by Date.parse • Except the dd/mm/yyyy format
7. 7.

   month_day_year = Date.strptime(string, "%m/%d/%Y") rescue nil

8. 8.

   month_day_year = Date.strptime(string, "%m/%d/%Y") rescue nil generic_parse = Date.parse(string) rescue

   nil
9. 9.

   month_day_year = Date.strptime(string, "%m/%d/%Y") rescue nil generic_parse = Date.parse(string) rescue

   nil day_month_year = Date.strptime(string, "%d/%m/%Y") rescue nil
10. 10.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1
11. 11.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 0 1 1 1 0 0 1 0 1 X 1 1 0 1 1 1
12. 12.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 1 0 1 1 1 0 0 1 0 1 X 1 1 0 1 1 1
13. 13.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 1 0 1 1 0 1 0 0 1 0 1 X 1 1 0 1 1 1
14. 14.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 X 1 1 0 1 1 1
15. 15.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 X 1 1 0 X 1 1 1
16. 16.

    month_day_year generic_parse day_month_year result 0 0 0 0 0 0

    1 X 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 X 1 1 0 X 1 1 1 1
17. 17.

    Makes your boolean functions simpler! Karnaugh map

18. 18.

    0 X 0 1 1 X 1 X generic_parse *

    day_month_year month_day_year 1 0 00 01 11 10
19. 19.

    0 X 0 1 1 X 1 X generic_parse *

    day_month_year month_day_year 1 0 00 01 11 10
20. 20.

    0 X 0 1 1 X 1 X generic_parse *

    day_month_year month_day_year 1 0 00 01 11 10
21. 21.

    0 X 0 1 1 X 1 X generic_parse *

    day_month_year month_day_year 1 0 00 01 11 10
22. 22.

    month_day_year 0 X 0 1 1 X 1 X generic_parse

    * day_month_year month_day_year 0 00 01 11 10 1
23. 23.

    month_day_year ∨ ¬generic_parse ∧ day_month_year 0 X 0 1 1

    X 1 X generic_parse * day_month_year month_day_year 0 00 01 11 10 1
24. 24.

    month_day_year ∨ ¬generic_parse ∧ day_month_year ∨ generic_parse ∧ ¬day_month_year 0

    X 0 1 1 X 1 X generic_parse * day_month_year month_day_year 0 00 01 11 10 1
25. 25.

    ((month_day_year ? 1 : 0) + ((day_month_year ? 1 :

    0) ^ (generic_parse ? 1 : 0)) == 0) month_day_year || generic_parse
26. 26.

    Thank you! Irina Bednova @jafrog www.jafrog.com