World: r3wp

ctx: context bind [
	chars: charset [ #"A" - #"Z" #"a" - #"z" #"0" - #"9" #"-" #"_"]
	non-chars: complement chars

	set 'copy-word has [start end end-rule car-pos] [
		if any [not focal-face not caret] [exit]
		
		car-pos: index? caret
		end-rule: copy []
		
		parse/all head caret [
			any [
			 	start: some chars end: (

     if all [car-pos >= index? start car-pos <= index? end] [end-rule: 
     'break]
				) end-rule
				| some non-chars (start: end: none)
			]
		]

  if all [start end] [write clipboard:// probe copy/part start end]
	]
] in system/view 'focal-face

view layout [
	area "This is some text to test"

 text "To copy the word under the cursor : hit CTRL+K or press the 
 button bellow"
	button "Copy word" #"^K" [copy-word]
]

There's a nice example of BIND. The whole block of words is first 
BINDed to the system/view object. Only the words that already exist 
in system/view (like 'copy-word) will be rebinded, (because objects 
cannot be extended with new words).

*Then* CONTEXT starts building a new object! of its own, from the 
spec block of binded words. But it only puts the set-words (eg. chars: 
non-chars:   but *not* 'copy-word) into the new object.

So it's a double-bind :-)

Thank you DideC this is what i was looking , i thought that parse 
will do the trick  I just did not know how. All i need to do now 
is see how fast this works with a 100KB text file.

I have been looking at scripts Anton on Bind ( found over 40 at rebol) 
. This is great !!! 8D

I'm not a parse guru myself. May be there is a simpler solution.

donno but it does what i need  =)  and it looks "easy" hmmm I can 
see why someone can get addicted to rebol. I need to study more about 
bind and parse.

is it possible to use an object variable for a VID item, such as 
obj: make object! [t: none] where I would like view layout [obj/t: 
button "hello"] in some way? it doesn't work...

Yes, it is possible but requires a little work...

o: context [var: none]
layout [button with [o/var: self]]
o/var/type ;== face
o/var/style ;== button

Hm...  Most elegant solution to that problem that I have seen!

very nice indeed :-)

You just need to watch out for button facets which have the same 
name as your object 'o

For example, don't do this:
text: context [var: none]
layout [button with [text/var: self]]
** Script Error: Cannot use path on none! value
** Where: forever
** Near: text/var: self

You could avoid that with some binding.

thanks for the suggestions :-) I'm doing it differently now though...

The most elegant solution would be to patch layout so it accepts 
set-paths.

Speaking of double bind, I have no clue of the how-to to this clue. 
 In Ocaml we can make co-recursive definitions, also with negation. 
 But when I try this on Rebol, it claims the value before I have 
the time to define it:  a: not b and b: not a.   Interp: ** script 
error, b has no value.  What is the method ?  Or are we out of paradise? 
 I could use that as a form of loop, or a form of lexical closure 
to model some linguistic phenomenas.  But how?  We know the problems 
of complement of complement, but as a function value it should be 
feasible.

Do you have an example,  besides:
a: not b
b: not a

In rebol this are executed serially, so the first statement fails 
because b is not defined.

A pair number cant be defined without impair. pair is impair +1 and 
impair is pair +1.  So we have to define both at the same time.  
In logic, the negation is a function where true is false and false 
is true.  Not and complement are native to rebol.  If I try a: not 
'b b: not ''a. asking the value of a, :a, does not return not b but 
false.   Something like this does not seem to work.  What I want 
is criss-crossed functions one defined by the other.  In principle, 
Rebol being functionnal.   It should be simple, a one liner, but 
I am too newbee to find the elegant way to do this.

Normand, can you give us the actual code that is tripping you up 
here?  Perhaps with a look I could help you out...

Normand, seems you do not define functions, but executes the expressions 
directly?
pair: func[][impair + 1]
impair: func[][pair + 1]
the code makes no sense but rebol accepts it perfectly.

Normand: don't you mean this?:

odd?: func [i] [either i = 0 [false] [even? i - 1]]
even?: func [i] [either i = 0 [true] [odd? i - 1]]
odd? 11

warning: odd? and even? are already defined in Rebol, you might prefer 
to use names like pair? and impair? instead like you wrote above

Thanks for the answer.  I am aiming in the direction of corecursive 
types, to model a category thing.  So the following works.

Co-recursive types:
>> owed: func [x] [either paid? x [negate x][false]]

>> owed?: func [x] [either all [integer? x negative? x] [true] [false]]
>> paid: func [x] [either owed? x [negate x] [false]]

>> paid?: func [x] [either all [integer? x positive? x] [true] [false]]
>> a: 5
== 5
>> owed a
== -5
>> owed? a
== false
>> owed? b: owed 5
== true
>> a: paid b
== 5
>> paid? a
== true
>> paid? paid -5

Now I need custom types.

--Type inference from a newbee point of view:

What if I wanted to form true (but un-native) datatypes ?  To program 
them, I shall use the same method as other types in Rebol: 

To mention the type as its value : seasoning!: seasoning!, like the 
definition of the type money!: 'money.

Rather, I would like to do type inference as they do, for example 
in ML (I adapt the example from Felleisen's LittleMLer):

So I would need to define a new type and verify the type of a word 
with type?
seasoning!: ('salt or 'pepper)
Unfortunately this does not seems possible 
** Script Error: Cannot use or~ on word! value
** Near: 'salt or 'pepper
In Rebol:
>> source integer!
integer!: integer!
type? 1
== integer!
but
natural!: (0 or natural +1)
Type inference:
seasoning? salt
Would like the answer == seasoning
is-of-type? 'salt seasoning
Would like the answer == true

Am I forced to turn to Ocaml to do this?  I am stuck.  Thanks for 
any help!

I don't know exactly what you can accept and what not, but this will 
work:

seasonings: [salt pepper]


seasoning?: func [value [any-type!]] [found? find/only seasonings 
get/any 'value]
seasoning? 'salt

As far as I know it is not possible to define new types.


Not sure that would solve your problem anyway.  A word can point 
to a value that has only *one* type (ignoring the heirarchy -- eg 
block! is also series!). So complex assertions about something would 
not be easy.


Maybe rethink the need.....Use objects to hold both a value and a 
type:
>> item: make object! [value: 'salt type: 'seasoning]
>> item/type
== seasoning
>> 'seasoning = item/type
== true

You could encapsulate that in a couple of functions and expand the 
scope (maybe make type a block with multiple values)

Gabriele Santilli has made some custom types. I don't remember having 
fully understood how it works, so I can't tell you how he did it 
! But it can be found here:
http://www.colellachiara.com/soft/YourValues/libs/

custom-types.r is GPL.

(It's really very clever. :)

Just reading the code... Needs a demo.
custom-types.r  needs  standard-actions.r

I'll try to make one.

Hmm, there seems no easy way to make a demo. Gabriele is using an 
include mechanism (prebol.r I think) from the SDK . But it looks 
like
http://www.colellachiara.com/soft/YourValues/main.r
is the starting point.

Gabriele, if you're listening, the header of http://www.colellachiara.com/soft/YourValues/yourvalues.r
contains:
	File: %main.r   ; <-- should be %yourvalues.r   ??

Gosh, it's too hard for me to do in any reasonable time. I suggest 
looking at the code to figure out the method used, then see if you 
can make your own custom types.

Anton: the header is wrong because that file is generated with prebol 
using main.r

(a version of prebol with some minor modifications.)

about an example: there should be a complex.r in that dir that is 
a bit outdated (lacks support for molding and loading) but should 
be a good start. also template.txt is the starting point to create 
a new type.

you need to use starred actions on them though, i.e. add* instead 
of add, insert* instead of insert and so on, as well as make* and 
to*.

maybe somedaye i'll have the time to finish this stuff and add docs...

:) Now I think I remember I asked you that about the File: before 
sometime...

but, i'm not 100% sure Normand really needs this. custom types are 
not always the most elegant solution; actually, they are very rarely.

What are you up to these days anyway ?

also, i would really discourage a newbie from using that stuff as 
it is very experimental :-)

finishing the detective version 3, then (don't know if i can say 
that, so i won't.)