[REBOL] Why do 'append and 'repend return 'head series?
From: al::bri::xtra::co::nz at: 10-Aug-2002 16:29
Why do 'append and 'repend return the head of the series? (I'm using latest
Rebol/Core)
>> source append
append: func [
{Appends a value to the tail of a series and returns the series head.}
series [series! port!]
value
/only "Appends a block value as a block"
][
head either only [
insert/only tail series :value
] [
insert tail series :value
]
]
>> x: 'test/foo/bar
== test/foo/bar
>> append x 'ping
== test/foo/bar/ping
>> x
== test/foo/bar/ping
>> x: at x 3
== bar/ping
>> x
== bar/ping
>> append x 'tau
== test/foo/bar/ping/tau
>> x
== bar/ping/tau
Would it be better for 'append and 'repend to return the 'series, instead of
the 'head of the 'series?
In other words, like:
Append: func [
{Appends a value to the tail of a series and returns the series head.}
Series [series! port!]
Value
/Only "Appends a block value as a block."
][
either only [
insert/only tail :Series :Value
] [
insert tail :Series :Value
]
:Series
]
(I've added in ":" to allow use of the above on Rebol/View with path! data
type for the series.)
After all, if one has set the position in a series explicitly, why should a
function return the series at a different position?
Andrew Martin
ICQ: 26227169 http://valley.150m.com/
