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@@ -3,6 +3,9 @@
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!! "it is better to have 100 functions operate on one data structure
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than 10 functions operate on 10 data structures" -- alan perlis
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+like that bruce lee quote about fearing the foe who practiced one kick
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+10,000 times, not the one who practiced 10,000 kicks once
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+
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Box and pointer diagram of (cons 1 2)
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: | +-----+-----+
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@@ -436,3 +439,39 @@ to generate unique permutations of a set, {1 2 3} {2 1 3} {3 1 2} etc
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(filter (lambda (x) (not (= x item)))
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sequence))
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#+END_SRC
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+** 2.2.4 Example: A Picture Language
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+we are going to explore data abstraction, closure, and higher-order
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+procedures with the picture language
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+
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+the language combines procedures as data
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+
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+the picture language has only one primitive: painter
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+
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+we can combine imagues by constructing new painters from given
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+painters
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+
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+eg flip-vert takes a painter and produces a painter that paints
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+upside-down
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+
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+we can combine these pictures with all the power of plain ol' scheme
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+
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+im not really interested in this section: i see what they are getting
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+at and the lecture was dope, but i feel like im sitting on my thumbs
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+with no way to actually use painters
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+
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+i do like the connection to geb
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+
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+LEVELS OF LANGUAGE FOR ROBUST DESIGN
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+
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+ - stratified design :: a complex system should be structured as a
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+ sequence of levels that are described using a sequence of
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+ languages
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+
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+each part is constructed using what it considers to be primitive
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+
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+the level above takes those constructs as its primitives
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+
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+the level below uses hidden concepts that are its own idea of
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+primitive
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+
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+!! means of abstraction appropriate to the current level of detail
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