CS 227 meeting -*- Outline -*-

* context for learning Scheme

** Bridge from Unix
*** was Unix hard to learn and use?  Was it unforgiving?
	remember that when you design user interfaces
		hard to make one that is easy to use and forgiving
	remember the level of precision
		this is also a characteristic of Scheme (and other prog langs)

*** Unix shell is a command interpreter
	reads command, does it, repeats
		show cp, mv, rm
		vs. echo cp...
** Scheme interpreter
	like a calculator
		reads expression, evaluates it, shows you its value
	can calculate extremely complex things, not just numbers
		e.g., given the current weather conditions (expression),
				will it rain tomorrow (value)
** Scheme programming language
	instructions that tell Scheme interpreter what to calculate
*** parts of a language
---------------------
  PARTS OF A LANGUAGE

		Scheme		English

primitives:	numbers,	sounds,
		symbols, lists	words

means of
combination:	if, cond, ...	grammar

means of
abstraction:	lambda		naming
---------------------
	we start with the primitives