1. suggestion for 2.3
- Posted by aku at inbox.as
May 07, 2001
if I have a sequence:
seq =
{
{ 1, 2, 3},
{ 4, 5, 6},
{ 7, 8, 9},
{10,11,12}
}
and i want to get the first column ( 1,4,7,10 )
in version 2.2 i must use at least 1 'for' statement.
I suggest this for version 2.3:
a = seq[][1] -- a = {1,4,7,10}
a = seq[][1..2] -- a = {{1,2},{4,5},{7,8},{10,11}}
a = seq[][1..2][1] -- a = {1,2}
a = seq[] -- a = seq
but if:
seq =
{
{ 1, 2, 3 },
{ 4, 5 },
{ 6 }
}
a= seq[][2] -- subscript 2 out of bounds
it is very useful, for example:
findrep =
{
{ "Halo", "Helo" },
{ "This", "that" },
{ "bmp", "jpg" },
{ "find", "replace" }
}
so we can use:
for i = 1 to length(words) do
at = find( words[i], findrep[][1] )
if at then
words[i] = findrep[at][2]
end if
end for
2. Re: suggestion for 2.3
On Mon, 07 May 2001, aku at inbox.as wrote:
> if I have a sequence:
>
> seq =
> {
> { 1, 2, 3},
> { 4, 5, 6},
> { 7, 8, 9},
> {10,11,12}
> }
>
> and i want to get the first column ( 1,4,7,10 )
> in version 2.2 i must use at least 1 'for' statement.
>
> I suggest this for version 2.3:
>
> a = seq[][1] -- a = {1,4,7,10}
> a = seq[][1..2] -- a = {{1,2},{4,5},{7,8},{10,11}}
> a = seq[][1..2][1] -- a = {1,2}
> a = seq[] -- a = seq
>
This would indeed be useful in many ways - and it has been discussed here
before. So much so that it's been given a name "vertical slicing".
We can only hope that it's in Rob's list.
Regards,
Irv
