[REBOL] Re: Core 2.6 - Last minute requests - take your chance!
From: rotenca:telvia:it at: 5-Apr-2002 18:58
31) Some changes for switch:
a) do :value instead of do value (for function! and parens! datatype) and do
:case instead of do case (default)
b) a new refinement /only, to permit multiple cases like this:
switch/only 2 [1 2 3 [print "found"]] block!
switch/only 2 reduce [1 2 3 does [print "found"]] function!
a more simple solution could be to permit only block! datatype for /only:
switch/only 2 [1 2 3 [print "found"]]
another solution could be a different switch function, called
switch-multiple
or something like.
The more complex:
switch: func [
"Selects a choice and evaluates what follows it."
[throw]
value "Value to search for."
cases [block!] "Block of cases to search."
/only datatype "Evaluates only the first item of the datatype! which
follows the choice"
/default case "Default case if no others are found."
][
either value:
either only [
if value: find cases value [
until [equal? datatype type? first value: next value]
first value
]
][
select cases value
]
[
do :value
][
either default [do case] [none]
]
]
The more simple:
switch: func [
"Selects a choice and evaluates what follows it."
[throw]
value "Value to search for."
cases [block!] "Block of cases to search."
/only "Evaluates only the first block! which follows the choice"
/default case "Default case if no others are found."
][
either value:
either only [
if value: find cases value [
until [block? first value: next value]
first value
]
][
select cases value
]
[
do :value
][
either default [do case] [none]
]
]
---
Ciao
Romano
