Mailing List Archive: 49091 messages
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search

[REBOL] Re: reduce [unset!] compose [(unset!)]

From: rotenca:telvia:it at: 23-May-2004 18:22

Hi Anton,
> >> reduce [unset! either none [][]] > == [unset! unset] > > Why was the first unset! molded and the second formed?
The difference is that: reduce [unset!] is a block! with a word! and when you evaluate it, the word get its value, which is the datatype! unset!. while: reduce [either none [][]] is a block with an expression which, when evaluated, returns an unset value (not the datatype unset!). You can see also:
>> type? either none [][]
== unset!
>> type? unset!
== datatype!
> I like the above compose behaviour, it is useful, but > why doesn't the following unset value also disappear? > > >> compose [(unset!)] > == [unset!]
The same here. --- Ciao Romano