FEEDBACK:
not so much on bytes and masks &c.
don't let scanf drag you into a discussion of pointers
relate concepts more - e.g. parentheses after main and after printf
repeat questions from the audience
give a break midway, to allow students to ask questions

TUESDAY 5 JANUARY
this is the SIPB CCC
introduce self
	biggest class previously was 18 people; please break in w/ questions
how many Scheme programmers?  Pascal?  others?  any assembly languages?
some people say C is evil: I think of it more as chaotic neutral.
C is a lot like MIT: gives a lot of freedom, counts on you to use it wisely
by the end of this course, you'll have enough rope to hang yourself

getting help:
zctl add ccc \* \*
zwrite -c ccc -i help

BOOKS:
Kelley & Pohl, A Book on C
Koenig, C Traps and Pitfalls
K&R, The C Programming Language
others, for Pascal programmers
PLEASE DON"T BORROW THEM FOR A LONG TIME

notes - won't refer to them, but useful as a 2nd treatment
section 3 of the UNIX manual

SYLLABUS:
http://www.mit.edu/iap/c3/
mirrored at http://www.mattababy.org/~belmonte/Teaching/CCC/

structure of C is more understandable w/ historical context
1967: Martin Richards: BCPL
	an opposite pole from Algol (and later Pascal)
	on the PDP-7, everything was a "cell"
	"close to the machine" - everything is just an integer
	memory is just a big array
	this is simple and beautiful, but
	drives you up the wall when you want to do anything abstract
	the PDP-7 had something like four kilobytes of memory
		so BCPL was a small language
		depends on libraries, not built-ins
		in fact, in C, there are only 32 reserved words
	Ken Thompson: B
	Dennis Ritchie was playing with something called UNIX; invented C
	added some idea of types to B
	but types are fudged
	in Scheme, can you do this:
		(+ #\A 5)
	in Pascal, can you do this:
		'A' + 5
	EVERYTHING'S AN INTEGER, OR COMPOSED OF INTEGERS
		ASCII
		fractions in scientific notation
		even memory addresses! (much more about this later)
	C is not a strongly typed language

hello.c
cc -g -o hello hello.c
add gcc; gcc -g -o hello hello.c (which to use? a religious question.)
comments
main (compare Pascal's "program" keyword)
return type
blocks
printf() and stdio
	string constant
	\n (otherwise prints continuously - example)
return (suppose we left it out?)

lint (useful for some of the bugs we're going to talk about)
add gnu; gcc -wall

fahr.c
declarations and statements
variables and types - different from Scheme - Scheme uses types implicitly
	char, int, short, long - typically 1, 2 or 4, 2, 4
	float, double - IEEE 4, 8
	signed, unsigned modifiers - specify use of MSb
	note no "string" type - we'll get to that
initialisation
assignment - = vs. == - compare Pascal
	statements & exprs - can have a=b=5
	can have x++ as stmt or expr
	comma operator - will see later - for example x++, y++;
order of operations
format strings - %d %f %c %s, and others
	%e scientific, %g shorter of float or sci.
the call to printf is actually an expr - returns # of chars printed

fahr.c, v1
scanf - use reference operator (PITFALL!)
returns # of inputs converted

fahr.c, v2
doubles are long floats
why no \n in prompt?
field width specs
why %lf in scanf but no 'l' in printf?  argument promotion to double or to int

fahrcels.c, v0
#include <stdio.h>
scale is an int not a char, because getchar() can return EOF
conditional statement
	takes Boolean
	but Boolean is implemented as int
	logical ops in C produce int 0 or int 1
blocks are compound stmts - like Pascal's "begin" and "end"
what would happen if we left out the bottom set of braces?  (bad ctrl flow)
the top set? (sn. err.)

fahrcels.c, v1
another logical op, ||
on parenthesising Boolean exprs - don't rely on precedence 'cause it'll bite you

fahrcels.c, v2
bitwise ops are vector versions of logical ops
explain hex numbers - each nybble is a digit
remember chars are just numbers
could we use logical && here? (NO.)
usefulness in reading hardware registers, decoding flags, &c.
	(ex: PC game port at *(char *)0x201: h,v,x,x,b1,b2,x,b3)
	what op do I use to read each bit?  what mask?
	another ex: what op do I use to make an even number odd?

fahrcels.c, v3
predefined functions in ctype.h - <> - on Athena, /usr/include

fahrcels.c, v4
sometimes we want to write a conditional within an expr, inside another stmt
	(easily abused and obfuscated!)

fahrcels.c, v5
shorthand ops - take inspiration from assembly languages

fahrcels.c, v6: FIND THE BUGS!

WEDNESDAY 6 JANUARY
review if/else; go over hw

numwords.c:
switch (like Pascal's "case")
pitfall: terminate each case with a "break"
use "default" to catch bugs and error conditions

factorial.c:
"L" suffix
for and while

peasant.c:
for, with some bitwise ops
invariants, guards, bounds
get them to read the code and state the algorithm

preprocessor.c

bignumwords.c:
functions - pass parameters on the stack

EXPLAIN do-while

GIVE OVERVIEW OF INTERPRETER PROJECT
go over assignment: scanner.h & scanner.c

THURSDAY 7 JANUARY <jcyang>
quadratic.c: math library; static data; storage classes in general
iteration and recursion
scope

FRIDAY 8 JANUARY

complex.h:
a few ways to do this -
struct - "a tagless union, structure, or enumeration specifies a unique type"
tagged struct and typedef are almost equivalent in functionality
	why would you want to use a typedef?
	(to hide implementation as a struct - data abstraction)
		#defines.  note parenthesisation

complex.c:

call-by-value causes a lot of copying
	talk about the way parameters are passed on the stack
	and local (automatic) variables are allocated on the stack
		they go away when the function returns
better to use pointers
review RAM model
review pointer usage in scanf calls

pcomplex.c:

string.c: arrays, pointers, and strings
(why no & on string var name in scanf?)
HOMEWORK: use an array of structs to implement a database

TUESDAY 12 JANUARY
median.c: multidimensional arrays vs. arrays of pointers; pointers to functions; casts
echo.c: argc and argv
llist.c, llist.h: 
if time allows, get the class to write a bubble-sort
HOMEWORK: alter the median routine to take a median of keyed structs
HOMEWORK: think about the two-dimensional-array version of median.c
HOMEWORK: make some of the previous programs take command-line arguments

WEDNESDAY 13 JANUARY
malloc and free - different from heap allocation in Scheme & Pascal
modular construction
gdb
HOMEWORK: parser.c

THURSDAY
file i/o - fopen & fclose, fscanf & fprintf, fread & fwrite, ftell & fseek
HOMEWORK: modify parser.c to take input from a file; write evaluator.c

FRIDAY
special topics and catch-up time