User talk:TimToady: Difference between revisions

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==On "That Goes Without Saying (or Does It)"==

I liked the use of RC. Not much the language comparisons made (especially against Python ;-), although it was good to see how Perl 6 did things. A longer review is here: [http://paddy3118.blogspot.com/2011/03/that-goes-without-saying-or-does-it-it.html "That Goes Without Saying (or Does It)". It didn't!]. --[[User:Paddy3118|Paddy3118]] 07:37, 12 March 2011 (UTC)

: I also enjoyed the presentation (which I found through Paddy's blog). In the spirit of your talk, I thought it might be worth pointing out that one of the things that J "doesn't make you say" is how to clean up after yourself. Which is one of the reasons (among others) that J's RMS algorithm is so much shorter than Perl6's.

: In effect, '''<tt>f&.g</tt>''' means "do '''<tt>g</tt>''', followed by '''<tt>f</tt>''', then undo '''<tt>g</tt>'''". For example: "fetch some milk" means "walk to the store, buy some milk, and unwalk to the store", except the return trip is implied. In J, we would use '''<tt>&.</tt>''' to express this as '''<tt>buy_milk&.walk_to_store</tt>''' .

: This pattern is ubiquitous in real life and in computing. To lay pipe, you dig a trench, lay the pipe, and fill the trench. To wash the dishes, you fill the sink, apply soap, scrub, rinse off the soap, and empty the sink. To perform surgery, you anesthetize the patient, cut him open, fiddle his bits, sew the cuts, and wake him up. To become a Perl programmer, you're born, you learn Perl, and you die. Some [[j:Essays/Under|computational examples]] are available on the J wiki.

: The anesthesia example suggests a name for this operation: "'''operate<tt>&.</tt>anethesia'''" reads "'''operate <ins>under</ins> anesthesia'''". Analogously, J's RMS algorithm, '''<tt>(+/ % #)&.:*:</tt>''', may be read '''average <ins>under</ins> square''' .

: So perhaps Goldilocks should consider throwing off her blankets, crossing the room, and getting under the covers with us J guys :) (Or maybe you should implement '''&.''' in Perl6. You stole all our other good ideas anyway ;)

: --[[User:DanBron|DanBron]] 23:43, 6 November 2012 (UTC)