COMP 3007 Lecture Notes - Lecture 2: Polish Notation, Operand, Evaluation Strategy
19 Oct 2018
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Document Summary
Lisp = list + processing: formalism for reasoning about the use of recursive equations as a model of computation, fully functional language, scheme, dialect of lisp. Important feature: processes, called procedures, can be manipulated as data. Expressions: scheme has a read-evaluate-print-loop (repl) displays the result of evaluating an expression, numbers, ex. 3: ex. (define size^2 4, variables are not case sensitive, hello is the same as hello. Interpreter must maintain name-object pairs: this memory is called the environment (global environment) Compound procedures: elements of scheme that must appear in any powerful programming language, 1. Numbers and arithmetic operations are primitive data and procedures: 2. Nesting of combinations provides a means of combining operations: 3. Suppose we want x squared plus y squared: (define (sum-of-squares x y) (+ (square x) (square y)): can redefine procedures, ex. (define + -, parameter can have same name as procedure, ex. (define (square square) (* square square))
