[REBOL] Re: comments for beginner ugly code ;-)
From: lmecir:mbox:vol:cz at: 18-Mar-2005 9:31
[sags--apollo--lv] napsal(a):
>O'k!
>I am unshure how in this case the works 'err!
>Is the refinement /local err is for generating error messages?
>
>brgds
>Janeks
>
/local is a refinement signaling that the variables following it are
local variables. That means, that 'err is a local variable used to
store
intermediate result.
Below is a more "polished" Default version. The Fault block may use
Error variable "knowing" the error value.
default: func [
{Execute code. If error occurs, execute fault.}
[throw]
code [block!] {Code to execute}
fault [block!] {Error handling code}
] [
either error? set/any 'code try code [
fault: make function! [[throw] error [error!]] fault
fault code
] [get/any 'code]
]
Examples:
>> default [join "apples" "pears"]["no good"]
== "applespears"
>> default [join "apples" "pears" / 0]["no good"]
== "no good"
>> default [join "apples" "pears" / 0][print mold disarm error]
make object! [
code: 312
type: 'script
id: 'cannot-use
arg1: 'divide
arg2: 'string!
arg3: none
near: [join "apples" "pears" / 0]
where: 'default
]
-Ladislav
