slice based on base and width
I find myself writing the following a lot: a[base..base+width] to get the slice starting at 'base' of width 'width'. In verilog, we select members of a vector/array in three ways a[c : d] //D: a[c .. d+1] a[c +: d] //D: a[c .. c+d] a[c -: d] //D: a[c-d .. c] Borrowing a bit from verilog, could we make two new operators, maybe +.. and -.. that allow us to do the same? I could then write e.g. a[base+..width] instead of the more verbose a[base..base+width]
Re: slice based on base and width
a[c -: d] //D: a[c-d .. c] I think this should be a[c -: d] //D: a[c-d+1 .. c+1], e.g. a[5 -: 2] == [a[4], a[5]]
Re: slice based on base and width
On Sunday, 8 September 2013 at 10:53:23 UTC, Øivind wrote: a[c -: d] //D: a[c-d .. c] I think this should be a[c -: d] //D: a[c-d+1 .. c+1], e.g. a[5 -: 2] == [a[4], a[5]] try a[base][0..width]
Re: slice based on base and width
On 2013-09-08, 14:02, Chang Long wrote: On Sunday, 8 September 2013 at 10:53:23 UTC, Øivind wrote: a[c -: d] //D: a[c-d .. c] I think this should be a[c -: d] //D: a[c-d+1 .. c+1], e.g. a[5 -: 2] == [a[4], a[5]] try a[base][0..width] That throws safety out the window for one. If you want safety and no new language features, this should work: a[base..$][0..width] -- Simen
Re: slice based on base and width
On Sunday, 8 September 2013 at 12:08:50 UTC, Simen Kjaeraas wrote: On 2013-09-08, 14:02, Chang Long wrote: On Sunday, 8 September 2013 at 10:53:23 UTC, Øivind wrote: a[c -: d] //D: a[c-d .. c] I think this should be a[c -: d] //D: a[c-d+1 .. c+1], e.g. a[5 -: 2] == [a[4], a[5]] try a[base][0..width] That throws safety out the window for one. If you want safety and no new language features, this should work: a[base..$][0..width] Thanks Still a little verbose, but at least you don't have to type the same things twice. I guess the double slice will be optimized into a single one at least for release mode, so there should be no performance degredation?
Re: slice based on base and width
On 9/8/2013 6:03 AM, Øivind wrote: That throws safety out the window for one. If you want safety and no new language features, this should work: a[base..$][0..width] Thanks Still a little verbose, but at least you don't have to type the same things twice. I guess the double slice will be optimized into a single one at least for release mode, so there should be no performance degredation? Try it and see. If it isn't, feel free to file an enhancement request for the optimizer!
