[Jscheme-user] hack of the day - The cost of abstracting an idiom

[Ken A. <kan...@bb...>]

I wrote this piece of code today and it struck me:

(define (readCountryData)
  (sort 
   (remove-duplicates
    (readingTabData
     (File. "../dafif/Dafift/AppC/appc_cc_icao.txt")
     (lambda (country country_name icao_rgn usage)
       (list country country_name))))
   (comparator string<? car)))

(define (readingTabData file f)
  (map* (lambda (r) (apply f (vector->list (.split r "\t"))))
        (BufferedReader. (FileReader. file))))

Now, this code can be improved in a lot of ways, but it did what i wanted - grind over a tab separated file, extract the fields i wanted, and sort the result.  It also abstracted out readinging from a tab separated file so it can be resused.

While you might argue that i should have produced an iterator to be Java compatible, to do it in Java, you'd need  an interface with methods call and apply, and each of the 4 loops would require at least 50% more lines of code.