(*Assn99 - Coding Style Template for 15-212*)
(*Name: Uland Y. Wong*)
(*Andrew ID: UYW*)
(*Section: C*)

(*coding_standard.sml - file implementing the coding standard*)
(*make sure you name your files EXACTLY the same as our templates
	and use the exact interfaces provided by our function stubs
	or you will receive 0 points.*)

(*--Multi Line Comments --
	indent after the first line and 
	continue indentation until the
	last line of text*)
	
(*--Make sure your code does not extend above 80 columns---------------------*)

(*if-else statements*)	
if true then 
	TextIO.print "true"
else
	TextIO.print "false"
	
(*let statements*)	
(*use if helper functions/values are used
	only by a single clause of the function
	calling function*)
fun letFunc	[] = []
  | letFunc (a::b) = 
	let
		(*comments above intermediate values*)
		val sum = Real.abs a
		val idx = Int.toString 5
	in
		sum::(letFunc b)
	end	
	
(*local statements*)
(*use if a helper function is common to
	all clauses of the calling function*)
local
	(*helper function comments*)
	fun dosomething () = "a"
in
	fun localFunc 0 = dosomething()
	  | localFunc 1 = dosomething()
	  | localFunc n =  dosomething()
end	

(*case statements*)
(*use to deconstruct data types or to
	simplify complex if-else statements*)
(case xList of
	[]		=> "nil"
  | [1,2,3] => "123"
  | [1,2,n] => "12-list"
  | [_,_,_] => "generic list of length 3"
  | (a::b)	=> "generic list"
  | _		=> "wild card match"
)

(*Some problems with current student code*)
	  
(*Do not overuse type annotations. Your code should work
	without them. If it does not, something is wrong.*)
fun ridiculous (x:int) (y:int) : int = (x:int) + (y:int) : int

(*Avoid excessive parentheses*)
fun thisIsNotLisp (((a),(b))) = ((a) * (b))

val h = {a = 1, b = 2, c = 3} (*do not put comments here*)

(*put spaces between infix operations and after commas*)
val _ = TextIO.print ("I"^"can't"^"read"^"your"^"code")

(*if your function has a lot of intermediate variables
	or a lot of pattern matches, use somewhat descriptive
	names for them*)
fun hardToUnderstand (a::b::c) (f as (v::x::y)) = (b::x::c) @ [a] @ y @ f 

(*Make Sure your Proofs are Structured like the following*)
(*
	1.2) Proof: class 15-212 = "tough as nails"
	
	Method: Prove by Induction on the size of 15-212 lecture
	
	Base Case
		[x] = "got an f in 15-212" 
			-the base case is satisfied
	
	Inductive Hypothesis
		Assume that a class of size n finds 15-212 tough as nails
	
	Inductive Step
		pain ("15-212","me")	= "the"
								= "world" 
								= "hates" by IH
								= "me"
							
								QED
*)

(*Dont let us catch you using any of the following 
	unless specifically stated in the homework handout.
	-while loops
	-ref and bang
	-arrays
	-callcc
	-streams
	-anything else that's not purely functional
*)