Extending Operators in Perl with Operator::Util

NOTE: Operator::Util is an experimental module that is no longer actively maintained.

Presented at:
◦  2011-02-15: Perl Seminar NY (PerlSemNY), New York, NY

Transcript

1. Operator::Util Nick Patch Perl Seminar NY 15 February 2011
2. released yesterday
3. released yesterday i ♥ feedback
4. Perl 6 is pretty cool
5. meta-operators
6. meta-operators [ ] Z X » « ☺ ☺ ☺ ☺
7. reduction [+] 1..4 # 10 [*] 1..4 # 24 [~] 'a'..'d' # 'abcd'
8. zip (1,2) Z+ (2,3) # 3,5 (1,2) Z* (2,3) # 2,6 (1,2) Z~ <a b> # 1a,2b
9. cross (flat) (1,2) X+ (2,3) # 3,4,4,5 (1,2) X* (2,3) # 2,3,4,6 (1,2) X~ <a b> # 1a,1b,2a,2b
10. cross (lol) (1,2) X+ (2,3) # [3,4],[4,5] (1,2) X* (2,3) # [2,3],[4,6] (1,2) X~ <a b> # [1a,1b],[2a,2b]
11. hyper 1..4 »~« 'a'..'d' # 1a,2b,3c,4d 1..4 »~» 'x' # 1x,2x,3x,4x 1..4 «~» <x y> # 1x,2y,1x,2y 1..4 «~« <x y> # 1x,2y
12. more hyper! -« (1,2,3) # -1,-2,-3 [1,[2,3]] »++ # [2,[3,4]] %foo «+» %bar # intersection %foo »+« %bar # union %foo »+=« %bar # %foo = union
13. but it's not Xmas yet
14. cpanm Operator::Util
15. use Operator::Util qw( reducewith zipwith crosswith hyperwith );
16. reducewith a.k.a. reduce hyperwith a.k.a. hyper
17. reduction reduce('+', [1..4]) # 10 reduce('*', [1..4]) # 24 reduce('.', ['a'..'d']) # 'abcd'
18. zip zipwith('+', [1,2], [2,3]) # 3,5 zipwith('*', [1,2], [2,3]) # 2,6 zipwith('.', [1,2], ['a','b']) # 1a,2b
19. cross (flat) crosswith('+', [1,2], [2,3]) crosswith('*', [1,2], [2,3]) crosswith('.', [1,2], ['a','b']) # 3,4,4,5 # 2,3,4,6 # 1a,1b,2a,2b
20. cross (lol) crosswith('+', [1,2], [2,3], flat=>0) crosswith('*', [1,2], [2,3], flat=>0) crosswith('.', [1,2], ['a','b'], flat=>0) # [3,4],[4,5] # [2,3],[4,6] # [1a,1b],[2a,2b]
21. hyper hyper('.', [1..4], ['a'..'d'] ); hyper('.', [1..4], 'x', dwim_right=>1); hyper('.', [1..4], ['x','y'], dwim=>1 ); hyper('.', [1..4], ['x','y'], dwim_left=>1 ); # 1a,2b,3c,4d # 1x,2x,3x,4x # 1x,2y,1x,2y # 1x,2y
22. more hyper! hyper('prefix:-', [1,2,3]); hyper('postfix:++', [1,[2,3]]); hyper('+', \%foo, \%bar, dwim=>1); hyper('+', \%foo, \%bar); hyper('+=', \%foo, \%bar); # -1,-2,-3 # [2,[3,4]] # intersection # union # %foo = union
23. default ops zipwith(',', [1,2], ['a','b']) zip( [1,2], ['a','b']) crosswith(',', [1,2], ['a','b']) cross( [1,2], ['a','b']) # 1,a,2,b # 1,a,2,b # 1,a,1,b,2,a,2,b # 1,a,1,b,2,a,2,b
24. associativity reduce('-', [4, 3, 2]) reduce('**', [4, 3, 2]) # 4-3-2 = (4-3)-2 = -1 # 4**3**2 = 4**(3**2) = 262144
25. chaining reduce('eq', \@a) # all elements eq? reduce('!=', \@c) # no repeating elements? reduce('<', \@b) # ascending elements?
26. dwim for < 2 elems reduce('+', [] ) # 0 reduce('+', [5]) # 5 reduce('*', [] ) # 1 reduce('*', [5]) # 5
27. even more hyper! hyper('->', \@objects, 'run', dwim=>1) hyper('+', [[1, 2], 3], [4, [5, 6]], dwim=>1) hyper('prefix:-', {a => 1, b => 2, c => 3}) # call ->run() on each # [[5, 6], [8, 9]] # a => -1, b => -2, c => -3
28. resources git: github.com/patch slides: patch.github.com