-- (c) MP-I (1998/9-2006/7) and CP (2005/6-2012/3)

-- NB: this is not a library, it is just a script of demos.
-- The useful material can be found in libraries BTree.hs and LTree.hs

import Data.List
import System.Time
import System.Cmd
import GHC.IO.Exception
import Cp
import Exp
import BTree
import LTree

--- (a) BTree virtual data structure display ----------------------------------

--- Quicksort ------------------------------------------------------------------
qSort_vtree x = (pict. (anaBTree qsep)) x
--- Towers of Hanoi ------------------------------------------------------------
hanoi_vtree = pict . (anaBTree strategy)

--- (b) LTree virtual data structure display -----------------------------------

--- Fibonacci ------------------------------------------------------------------
fib_vtree n = (pict . (anaLTree fibd)) n

--- Mergesort ------------------------------------------------------------------
mSort_vtree [] = (expShow "_.html") (Var " ")
mSort_vtree l  = (pict.(anaLTree lsplit )) l

-- Double factorial ------------------------------------------------------------
dfac_vtree 0 = (expShow "_.html") (Var "1")
dfac_vtree n = (pict. (anaLTree dfacd)) (1,n)

--------------------------------------------------------------------------------

-- (d) A study of fibonacci ---------------------------------------------------

-- pointwise version of fib =  hyloLTree (either (const 1) add) fibd

fibpw 0 = 1
fibpw 1 = 1
fibpw n = fibpw (n-1) + fibpw (n-2)

-- linear version O(n) after mutual recursion law

fiblpw n = let (a,b) = aux n in b
         where aux 0 = (1,1)
               aux n = let (a,b) = aux (n-1) in (a+b,a) 

-- IO-monadic version o fibpw showing algorithm evolution

fibpwm 0 = return 1
fibpwm 1 = return 1
fibpwm n  = do putStr("\nfib("++show n ++") = ...\n");
		 a <- fibpwm(n-1) ;
                 b <- fibpw(n-2);
--               putStr("\nn-1="++show(n-1)++" n="++show(n-2)++" a+b="++show(a+b)++"\n");
                 return (a + b)

-- IO-monadic version o fibpw' showing algorithm evolution

fiblpwm n = do (a,b) <- auxm n ; putStr("\nresult="++(show b)++"\n")
         where auxm 0 = return (1,1)
               auxm n = do (a,b) <- auxm(n-1);
                               putStr("\nn="++show n ++" (a+b,a)="++show(a+b,a)++"\n");
			       return (a+b,a) 

-- measuring time costs:

trun f a =
        do
	start <- getClockTime
	print(f a)
	end <- getClockTime
	print (diffClockTimes end start)

tanalysis f f' a =
        do start <- getClockTime
	   print(f a)
	   mid <- getClockTime
	   print(f' a)
	   end <- getClockTime
	   print (diffClockTimes mid start)
	   print (diffClockTimes end mid)
	   print $ div (tdPicosec(diffClockTimes mid start)) (tdPicosec(diffClockTimes end mid))

-- trun fib 19
-- trun fiblpw 19