[REBOL] word datatype was contexts
From: rotenca::telvia::it at: 17-Sep-2001 14:07
> again, Romano,
hi, Joel,
Thank you for the explanation, now i see things more clearly.
> Actually, it does... In the on-line version of RCUG (the
> quickest one for me to check), section 5.1 "Word Names",
> begins with the statements:
>
> Words are composed of alphabetic characters, numbers [sic],
> and any of the following characters:
>
> ? ! . ' + - * & | = _ ~
>
> A word cannot begin with a number [sic], and there are
> also some restrictions on words that could be interpreted
> as numbers. For example, -1 and +1 are numbers, not words.
Yes, i've found it. Appendix A-79.
> The statements you quoted above from RCUG are really talking
> about the standard rules by which REBOL translates text into
> internal values. They don't mean that that you can't override
> the normal assumptions and force REBOL to create values (e.g.
> words) out of something that doesn't follow the standard rules.
They don't say neither than horse can fly.... :-)
> >> confusion: reduce [to-set-word "%yikes" 2.54]
> == [%yikes: 2.54]
> >> do confusion
> == 2.54
> >> print %yikes
> yikes
> >> type? %yikes
> == file!
>
> What's happening? We forced the creation of a word whose
> spelling is not "normal" because it begins with a percent
> sign (normally used as a prefix to indicate file names).
> Therefore, when we say PRINT %YIKES at the interactive
> prompt, REBOL applies the normal rules and translates the
> next thing after PRINT into a file name.
I forgot than the input from console go to Load which applies "normal
rules"...
> In order to get
> back to the word we created with the non-standard name, we
> have to override the rules again...
>
> >> print get to-word "%yikes"
> 2.54
And also:
>> get first confusion
== 2.54
in this case I over-pass Load.
But there is another thing: every datatype has own rules, we can't trasform
anything in anything.
to-issue put always (i think) a "#" in front of any string, you can't force
this.
to-integer doesn't like the number: "i'm not a number"
So, some rules exist for every datatype.
The only rule i can find for word! is
length? string >0
Conclusion: we can't made any assuntion on the mold format of any word.
But now i ask me: what are the true rules (beyond Load) of every datatype?
> Hope this helps!
Very, very useful and clear!
> -jn-
---
Ciao
Romano
