[REBOL] Re: Accessing nested Blocks + search in blocks
From: lmecir:geocities at: 5-Nov-2000 7:06
Hi,
I hope, that somebody can find some use for the following :
Rebol []
rtp: function [
{A referentially transparent way to invoke paths}
[catch]
block [block!]
] [head path stop] [
path: either stop: find block first [/] [
copy/part block stop
] [
stop: [none]
block
]
if not empty? path [
path: reduce path
if not word? set/any 'head first path [change/only path 'head]
if error? path: try [to-path! path] [
throw make error! {Invalid path representation}
]
]
do compose [(:path) (next stop)]
]
to-path!: function [
[catch]
path-block [block!]
] [path] [
path: make path! length? path-block
foreach element path-block [
throw-on-error [
if :element [insert/only tail :path :element]
]
]
:path
]
{
Example:
rtp [now 'time 'second]
a: [1 2 3]
rtp [a 1 + 1]
only: false
head rtp ['insert if only ['only] / tail a [4]]
only: true
head rtp ['insert if only ['only] / tail a [4]]
}
