[Compiler-sig] Slices

[Finn Bock]

Hi,

Trying again for some feedback on the slice production. I still can't
figure out how to use the existing Slice and ExtSlice so I tried to make
some changes like this:

         slice = Ellipsis | Slice(expr? lower, expr? upper)
              -- maybe Slice and ExtSlice should be merged...
-             | ExtSlice(expr* dims)
+             | ExtSlice(slice* dims)
+             | Index(expr value)

        boolop = And | Or


Which I use in the following way (one the slice part of the Subscript is
included):

L[1]

    slice=Index[value=Num[n=1]]

L[1:2]

    slice=Slice[lower=Num[n=1], upper=Num[n=2]]

L[1:2, 3]

    slice=ExtSlice[dims=[
        Slice[lower=Num[n=1], upper=Num[n=2]],
        Index[dims=Num[n=3]
    ]]


A single expr is wrapped by the Index(), a slice is ofcourse wrapped
with a Slice() and comma seperated list of slices is wrapped by a
ExtSlice() object.

Does it make sense?

regards,
finn