Using :word construct for refinement substitution does not work

[fvanzeveren]

In REBOL2, the following code is working fine and can be useful in many case:

>> f: func [/debug /info] [print "Hello"]
>> ref: 'debug
== debug
>> f/:ref
Hello
>>

But in REBOL3 (3.19.0), this does throw an error:

>> f: func [/debug /info] [print "Hello"]
>> ref: 'debug
== debug
>> f/:ref
** Script error: f has no refinement called :ref`

I am wondering whether this is by design... or a bug.

Thank you for your feedback.

[Oldes]

It is by design.. the get-word in the path is now (like in Red) used for a different purpose.. e.g.:

>> f: func[/a /b][? a ? b]
>> a: true b: false f/:a/:b
A is a logic of value: true
B is a none of value: none

[Oldes]

Here are related commits:
5d9af51
a14bf53
467ae8d

[Oldes]

Also note, that Rebol2 probably does not work as you expect:

>> f: func [/debug /info] [? debug ? info]
>> ref: 'debug f/:ref
DEBUG is a none of value: none ;<-------- still none!
INFO is a none of value: none

[fvanzeveren]

Thank you Oldes for your answer. I understand that it allows now conditional activation :)

I found a construction that, although less elegant than path substitution, remains very much in the spirit of REBOL.

if value? 'logger [
    level: case [
        debug   'debug
        warning 'warning
        error   'error
        true    'info
    ]
    log-path: to-path reduce ['log level]
    code-block: compose [(log-path) (message)]
    do bind code-block get 'logger
]

[Oldes]

To be hones, your construction looks too complicated to me ;-) Do you know, that there is built-in logging in Rebol3?

• There is log function at the system level, which may be used before any mezzanine is loaded.
• There is possible logger module at the mezzanine level, which may be used to redefine look or output of these system log messages.
• And sometimes (when speed is important and I don't want to waste execution time on hidden or too verbose logs, I use something like this in the TLS scheme.

[Oldes]

I can also imagine use of source pre-processor to insert logs only when developing some script, but I don't use it. It is good to be able turn on maximum verbosity sometimes.. especially with protocols, so one may see, what is going on internally (no black-box).