-- Some simple examples using arrays.  Requires array.gs.

-- Some applications, most taken from the Gentle Introduction ... -------------

timesTable = array ((1,1),(10,10)) [ (i,j) := i*j | i<-[1..10], j<-[1..10] ]

fibs n = a where a = array (0,n) ([ 0 := 1, 1 := 1 ] ++
                                  [ i := a!(i-2) + a!(i-1) | i <- [2..n] ])
fibs10 = fibs 10

wavefront n = a where a = array ((1,1),(n,n))
                             ([ (1,j) := 1 | j <- [1..n] ] ++
                              [ (i,1) := 1 | i <- [2..n] ] ++
                              [ (i,j) := a!(i,j-1) + a!(i-1,j-1) + a!(i-1,j)
                                           | i <- [2..n], j <- [2..n] ])

wave10 = wavefront 10

listwave n = [ [wf!(i,j) | j <- [1..n]] | i <- [1..n] ]
             where wf = wavefront n

eg1 = array (1,100) ((1 := 1) : [ i := i * eg1!(i-1) | i <- [2..100] ])

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

a1 = array (-5,5) []
a2 = a1 // [ 1 := True ]
a3 = a1 // [ 0 := a1 ]
a4 = array (-5,5) [ i := i*i | i <- [-5..0] ]