Term |
Definition |
Example |
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Atoms |
Like types: the fundamental items formed from bits |
27, 3.14, This-Phrase |
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Lists |
Sentence like objects containing atoms or other lists. |
'(this that the other thing) |
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Symbolic expressions / or [s-]expressions |
Atoms and lists collectively are called expressions. |
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setf |
(setf [<name> <list>]*) is an assignment of <list> to <name> |
(setf friends '(Dan Randy) enemies '(Satan)) |
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Data Types |
See Figure 1 |
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FIRST |
(FIRST LIST) returns the first expression in the list |
(FIRST (A B C)) --> A |
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REST |
(REST LIST) returns the expression after the first element of the list as a list |
(REST (A B C)) --> (B C) |
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QUOTE |
'(I J) will return a list with the elements I and J without trying to interpret I as a function |
'(A B C) --> (A B C) |
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CARs CDRs |
CAR == first, CDR == rest. Add a's or d's to string them to gether CADR == first rest |
(CADR '(A B C)) --> B |
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True and False |
T and NIL |
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CONS |
(CONS <exp> <list>) --> LIST == (exp list[1] ... list[n]) that is the contents of the list |
(CONS 'a '(b c)) --> (a b c) |
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APPEND |
(APPEND list list*) --> (content contents1 ... contentsn) |
(append '(a b c) '(a e f)) --> (a b c a e f) |
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LIST |
(LIST <exp>*) --> (exp1 ... expn) |
(LIST 'a 'b 'c) --> (a b c) |
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NTHCDR |
(NTHCDR <number> <list>) trims off the first <number> items from the list and returns the rest |
(NTHCDR 2 '(a b c)) --> (c) |
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BUTLAST |
(BUTLAST <number> <list>) trims off the last <number> itmes from the list and returns the rest |
(BUTLAST 2 '(a b c)) --> (a) |
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LAST |
(LAST <list>) --> (last-element) as a list |
(LAST '(a b c)) --> (c) |
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LENGTH |
(LENGTH <list>) --> number of items in the list |
(LENGTH '(a b c)) --> 3 |
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REVERSE |
(REVERSE <list>) --> reverses the order of the list |
(REVERSE '(a b c)) --> (c b a) |
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Association list / a-list |
A list of sublists where the first element in each sublist is used as a key for recovering the entire list. |
(setf Patti '((height 5-10) (weight 124))) where height and weight are the keys |
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ASSOC |
Is a way to access a-lists (ASSOC <key> <a-list>) |
(ASSOC 'weight Patti) --> 124 |
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FLOAT |
Forces a float result (FLOAT <exp>) --> float-value |
(float (/ 22 7)) --> 3.14286 vs. (/ 22 7) --> 22/7 which is a ratio |
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ROUND |
(ROUND <exp>) --> int remainder |
(round (/ 22 7)) --> 3 1/7 |
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MAX |
(MAX <list>) --> max element in list |
(max '(1 2 3)) --> 3 |
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MIN |
(MIN <list>) --> min element in list |
similar |
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EXPT |
Stand for exponent (expt number1 number2) --> number1^number2 |
(expt 2 3) --> 8 |
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|Integer
|
|Number---|Ratio
| |
| |Floating Point
|Atom---|
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Expressions -| |Symbol
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|LISTFigure 1