Using boolean logic to deal with dates

The unexpected application of Karnaugh maps in a Rails project

Transcript

1. For fun Using Boolean logic to deal with dates
2. The problem
3. The problem Parse a string to a Date object
4. The problem • Date could be in the mm/dd/yyyy format
5. The problem • Date could be in the mm/dd/yyyy format • Date could be in any format recognisable by Date.parse
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. month_day_year = Date.strptime(string, "%m/%d/%Y") rescue nil
8. month_day_year = Date.strptime(string, "%m/%d/%Y") rescue nil generic_parse = Date.parse(string) rescue nil
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. 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. 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. 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. 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. 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. 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. 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. Makes your boolean functions simpler! Karnaugh map
18. 0 X 0 1 1 X 1 X generic_parse * day_month_year month_day_year 1 0 00 01 11 10
19. 0 X 0 1 1 X 1 X generic_parse * day_month_year month_day_year 1 0 00 01 11 10
20. 0 X 0 1 1 X 1 X generic_parse * day_month_year month_day_year 1 0 00 01 11 10
21. 0 X 0 1 1 X 1 X generic_parse * day_month_year month_day_year 1 0 00 01 11 10
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. 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. 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. ((month_day_year ? 1 : 0) + ((day_month_year ? 1 : 0) ^ (generic_parse ? 1 : 0)) == 0) month_day_year || generic_parse
26. Thank you! Irina Bednova @jafrog www.jafrog.com