Just before I venture into updating to the correct beta d...
Raul's is elegant, single-pass and pretty spare. Here's a verbose,
inelegant,
multi-pass one, but it seems to work, except perhaps for the last
example,
below.
I stuck with _2 which means that with odd length strings an error is thrown
on the last pair which is actually not a pair, so needs to be catered for.
anyway, (it should appear on one line):
dedouble =: dtb@:((] ({.~ , 'X' , }.~) 1 (1 + 2 * i.)~ _2 =/\ ]) {.~
>:@#) ::($:@:,&' ')
dtb is delete trailing blanks, in strings, I think.
dedouble^:_'THEEQUICKBROWFFOOX'
THEXEQUICKBROWFXFOOX
dedouble^:_'THEEQUICKBROWFOOX'
THEXEQUICKBROWFOOX
This next example is a bit unlikely to occur, but is this what's required?
dedouble 'THEEQUICKBROWFOOOX'
THEXEQUICKBROWFOOOX
Raul's version doesn't agree with mine here! Is this result prederred?
rmdedouble 'THEEQUICKBROWFOOOX'
THEXEQUICKBROWFOOOX
Cheers,
Mike
On 04/02/2021 14:46, Raul Miller wrote:
Ah, I see it now -- I should have looked closer at your digraphs.
Here's a fixed version:
digra=: * 2 | i.@# + +/\
dedouble=: #!.'X'~ 1 j. [: digra #{.}.=}:
(I could not think of a good name for the "compress out splits of
non-digraphs" mechanism.)
The moral of the story here is that numeric calculations can often
replace simple recursive processes. (Because numbers can be defined
recursively.)
I hope this helps,
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