411 REFERENCE · Wikibooks
Rebol Programming/default
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
USAGE:
DEFAULT 'word value
DESCRIPTION:
Set a word to a default value if it hasn't been set yet.
DEFAULT is a function value.
ARGUMENTS
word -- The word (use :var for word! values) (Type: word set-word lit-word)
value -- The value (Type: any)
SOURCE CODE
default: func [
{Set a word to a default value if it hasn't been set yet.}
'word [word! set-word! lit-word!] "The word (use :var for word! values)"
value "The value"
][
unless all [value? word not none? get word] [set word :value] :value
]