I'll mention that Rebol does have SPLIT. Operates on strings, arrays...
>> split "your words here" space
== ["your" "words" "here"]
>> split [your elements + (are) here + + so split them] '+
== [[your elements] [(are) here] [] [so split them]]
It's dialected weirdly, so the thing you're splitting by can be a block but then it doesn't mean that block literally:
>> split "1234567812345678" [4 4 2 2 1 1 1 1]
== ["1234" "5678" "12" "34" "5" "6" "7" "8"]
I've never paid much attention to it, so I haven't put in my 2 cents on the design.
I don't want to change SPACED to ENSPACED :-/ so following the pattern and doing LINED and DELINED is probably the most consistent if it's SPACED and DESPACED.
A little strange, but seems okay:
>> spaced ["your" "words" "here"]
== "your words here"
>> despaced "your words here"
== ["your" "words" "here"]
>> lined ["a list" "of lines" "of text"]
== "a list\nof lines\nof text\n"
>> delined "a list\nof lines\nof text\n"
== ["a list" "of lines" "of text"]
LINED would be evaluative, like SPACED, unless you use an @[...] block.
Some people might be confused by DESPACED vs. UNSPACED. :-/ An interesting past naming decision was that DEQUOTE once meant "remove all quoting levels" while UNQUOTE meant "remove one quoting level"... but DEQUOTE and UNQUOTE seemed so interchangeable that DEQUOTE was named NOQUOTE