CSC104H1 Lecture Notes - Lecture 11: Association Football, Alonzo Church, Grace Hopper
19 Mar 2018
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;fill our databases with pictures (define database (list (list "ada lovelace" 1815 . ) (list "alan turing" 1912 . ) (list "alonzo church" 1903 . ) (list "grace hoppper" 1906 . ) (list "kurt goedel" 1906 . ) (list "miriam mann" 1907 . ))) > ;let us make sure that"s a list of lists, where each element has three elements. (check-expect (length (first database)) 3) > (check-expect (apply = (map length database)) #true) ;we will take a look at the new images in db, but first let"s make our database work less dependent on its "representation" ;"representation independence": our database happens to represent a person as: ;a list with a name, birth year, and photo, in that order. ;but the order is arbitrary: it is a property of our chosen "representation". Good software engineerning practice hides aspects, to make code clearer, less error-prone, and more adaptable/flexible. ;let us name the functions taht we used to extract each aspect of a person: (define name first)
