Attributes

Attributes

[Stéphane Goujet]

Hello,

  I would like to know what is the recommended way to use attributes in
Context.

  I manage to use use them with numbers, i.e. :
in Context : \attribute123=1
in Lua     : has_attribute(my_node, 123)

  But I would like to make that cleaner and use named attributes.
What is the Context way to declare and set attributes? Is it something
like this?
\defineattribute[myattr]
\dosetattribute{myattr}{1}

  And how do I then access them from Lua? Should it look like
has_attribute(mynode, attributes.myattr)
  or
has_attribute(mynode, attributes.xxxxx("myattr"))
  or something else?

Goodbye,
  Stéphane.
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___________________________________________________________________________________

Re: Attributes

[Hans Hagen]

On 4/20/2014 3:14 PM, Stéphane Goujet wrote:
> Hello,
>
>    I would like to know what is the recommended way to use attributes in
> Context.
>
>    I manage to use use them with numbers, i.e. :
> in Context : \attribute123=1
> in Lua     : has_attribute(my_node, 123)
>
>    But I would like to make that cleaner and use named attributes.
> What is the Context way to declare and set attributes? Is it something
> like this?
> \defineattribute[myattr]
> \dosetattribute{myattr}{1}
>
>    And how do I then access them from Lua? Should it look like
> has_attribute(mynode, attributes.myattr)
>    or
> has_attribute(mynode, attributes.xxxxx("myattr"))
>    or something else?

attributes.names[...]
attributes.numbers[...]

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
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Re: Attributes

[Stéphane Goujet]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 4516 bytes --]

On Tue, 22 Apr 2014, Hans Hagen wrote:

> On 4/20/2014 3:14 PM, Stéphane Goujet wrote:
>>     I would like to know what is the recommended way to use attributes in
>>  Context.
>>  What is the Context way to declare and set attributes? Is it something
>>  like this?
>>  \defineattribute[myattr]
>>  \dosetattribute{myattr}{1}
>>
>>     And how do I then access them from Lua? Should it look like
>>  has_attribute(mynode, attributes.myattr)
>>     or
>>  has_attribute(mynode, attributes.xxxxx("myattr"))
>>     or something else?
>
> attributes.names[...]
> attributes.numbers[...]

   Please have a look at my example (it is a bit long because it shows 
various possibilities) and its result.
    When I have not yet done a \defineattribute[myattr], node.has_attribute
returns 0 when I thought it should return nil.
   When I do \defineattribute[...], every attribute seems to get the same 
number (1024), but now node.has_attribute returns nil ...

=========================
Example
=========================
\starttext

\startluacode
 	mycallback=function(head)
 		if attributes.names==nil then
 			print "No attribute names at all"
 		end
 		if attributes.numbers==nil then
 			print "No attribute numbers at all"
 		end
 		for mynode in node.traverse_id(node.id("glyph"), head) do
 			if string.match("0ABCDEabcdefg", 
unicode.utf8.char(mynode.char)) then
 				print ("Glyph = 
"..unicode.utf8.char(mynode.char))
 				if attributes.numbers["myattr"]==nil then
 					print "No attribute number for 
myattr"
 				else
 					print ("myattr : number = 
"..(attributes.numbers["myattr"]))
 				end
 				if attributes.numbers["myattrb"]==nil then
 					print "No attribute number for 
myattrb"
 				else
 					print ("myattrb : number = 
"..(attributes.numbers["myattrb"]))
 				end
 				if node.has_attribute(mynode, 
attributes.numbers["myattr"]) then
 					print ("Attribute myattr = 
"..(node.has_attribute(mynode, attributes.numbers["myattr"])))
 				else
 					print "No attribute myattr"
 				end
 				if node.has_attribute(mynode, 
attributes.numbers["myattrb"]) then
 					print ("Attribute myattrb = 
"..(node.has_attribute(mynode, attributes.numbers["myattrb"])))
 				else
 					print "No attribute myattrb"
 				end
 				if node.has_attribute(mynode, 111) then
 					print ("Attribute 111 = 
"..(node.has_attribute(mynode, 111)))
 				else
 					print "No attribute 111"
 				end
 			end
 		end
 		return head
 	end

 	nodes.tasks.appendaction("processors", "before", "mycallback")
\stopluacode

0

\attribute111=-1
A

\attribute111=200
B

\attribute111=202
C

\attribute111=-1
D

\attribute111=-"7FFFFFFF
E

\defineattribute[myattr]
\defineattribute[myattrb]
a

\doresetattribute{myattr}
b

\dosetattribute{myattr}{500}
c

\dosetattribute{myattr}{502}
d

\doresetattribute{myattr}
e


\stoptext
======================


======================
Result :
======================
Glyph = 0
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
No attribute 111
Glyph = A
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
Attribute 111 = -1
Glyph = B
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
Attribute 111 = 200
Glyph = C
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
Attribute 111 = 202
Glyph = D
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
Attribute 111 = -1
Glyph = E
No attribute number for myattr
No attribute number for myattrb
Attribute myattr = 0
Attribute myattrb = 0
No attribute 111
Glyph = a
myattr : number = 1024
myattrb : number = 1024
No attribute myattr
No attribute myattrb
No attribute 111
Glyph = b
myattr : number = 1024
myattrb : number = 1024
No attribute myattr
No attribute myattrb
No attribute 111
Glyph = c
myattr : number = 1024
myattrb : number = 1024
No attribute myattr
No attribute myattrb
No attribute 111
Glyph = d
myattr : number = 1024
myattrb : number = 1024
No attribute myattr
No attribute myattrb
No attribute 111
Glyph = e
myattr : number = 1024
myattrb : number = 1024
No attribute myattr
No attribute myattrb
No attribute 111
======================

Goodbye,
   Stéphane.

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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: Attributes

[Hans Hagen]

On 4/22/2014 8:10 PM, Stéphane Goujet wrote:
> On Tue, 22 Apr 2014, Hans Hagen wrote:
>
>> On 4/20/2014 3:14 PM, Stéphane Goujet wrote:
>>>     I would like to know what is the recommended way to use
>>> attributes in
>>>  Context.
>>>  What is the Context way to declare and set attributes? Is it something
>>>  like this?
>>>  \defineattribute[myattr]
>>>  \dosetattribute{myattr}{1}
>>>
>>>     And how do I then access them from Lua? Should it look like
>>>  has_attribute(mynode, attributes.myattr)
>>>     or
>>>  has_attribute(mynode, attributes.xxxxx("myattr"))
>>>     or something else?
>>
>> attributes.names[...]
>> attributes.numbers[...]
>
>    Please have a look at my example (it is a bit long because it shows
> various possibilities) and its result.
>     When I have not yet done a \defineattribute[myattr], node.has_attribute
> returns 0 when I thought it should return nil.
>    When I do \defineattribute[...], every attribute seems to get the
> same number (1024), but now node.has_attribute returns nil ...

change this is syst-ini.mkiv:

\normalprotected\def\newattribute{\syst_basics_allocate\c_syst_last_allocated_attribute\attribute\attributedef\c_syst_max_allocated_register}


> =========================
> Example
> =========================
> \starttext
>
> \startluacode
>      mycallback=function(head)
>          if attributes.names==nil then
>              print "No attribute names at all"
>          end
>          if attributes.numbers==nil then
>              print "No attribute numbers at all"
>          end
>          for mynode in node.traverse_id(node.id("glyph"), head) do
>              if string.match("0ABCDEabcdefg",
> unicode.utf8.char(mynode.char)) then
>                  print ("Glyph = "..unicode.utf8.char(mynode.char))
>                  if attributes.numbers["myattr"]==nil then
>                      print "No attribute number for myattr"
>                  else
>                      print ("myattr : number =
> "..(attributes.numbers["myattr"]))
>                  end
>                  if attributes.numbers["myattrb"]==nil then
>                      print "No attribute number for myattrb"
>                  else
>                      print ("myattrb : number =
> "..(attributes.numbers["myattrb"]))
>                  end
>                  if node.has_attribute(mynode,
> attributes.numbers["myattr"]) then
>                      print ("Attribute myattr =
> "..(node.has_attribute(mynode, attributes.numbers["myattr"])))
>                  else
>                      print "No attribute myattr"
>                  end
>                  if node.has_attribute(mynode,
> attributes.numbers["myattrb"]) then
>                      print ("Attribute myattrb =
> "..(node.has_attribute(mynode, attributes.numbers["myattrb"])))
>                  else
>                      print "No attribute myattrb"
>                  end
>                  if node.has_attribute(mynode, 111) then
>                      print ("Attribute 111 =
> "..(node.has_attribute(mynode, 111)))
>                  else
>                      print "No attribute 111"
>                  end
>              end
>          end
>          return head
>      end
>
>      nodes.tasks.appendaction("processors", "before", "mycallback")
> \stopluacode
>
> 0
>
> \attribute111=-1
> A
>
> \attribute111=200
> B
>
> \attribute111=202
> C
>
> \attribute111=-1
> D
>
> \attribute111=-"7FFFFFFF
> E
>
> \defineattribute[myattr]
> \defineattribute[myattrb]
> a
>
> \doresetattribute{myattr}
> b
>
> \dosetattribute{myattr}{500}
> c
>
> \dosetattribute{myattr}{502}
> d
>
> \doresetattribute{myattr}
> e
>
>
> \stoptext
> ======================
>
>
> ======================
> Result :
> ======================
> Glyph = 0
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> No attribute 111
> Glyph = A
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> Attribute 111 = -1
> Glyph = B
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> Attribute 111 = 200
> Glyph = C
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> Attribute 111 = 202
> Glyph = D
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> Attribute 111 = -1
> Glyph = E
> No attribute number for myattr
> No attribute number for myattrb
> Attribute myattr = 0
> Attribute myattrb = 0
> No attribute 111
> Glyph = a
> myattr : number = 1024
> myattrb : number = 1024
> No attribute myattr
> No attribute myattrb
> No attribute 111
> Glyph = b
> myattr : number = 1024
> myattrb : number = 1024
> No attribute myattr
> No attribute myattrb
> No attribute 111
> Glyph = c
> myattr : number = 1024
> myattrb : number = 1024
> No attribute myattr
> No attribute myattrb
> No attribute 111
> Glyph = d
> myattr : number = 1024
> myattrb : number = 1024
> No attribute myattr
> No attribute myattrb
> No attribute 111
> Glyph = e
> myattr : number = 1024
> myattrb : number = 1024
> No attribute myattr
> No attribute myattrb
> No attribute 111
> ======================
>
> Goodbye,
>    Stéphane.
>
>
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
>
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive  : http://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________
>


-- 

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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archive  : http://foundry.supelec.fr/projects/contextrev/
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___________________________________________________________________________________

Re: Attributes

[Stéphane Goujet]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1058 bytes --]



On Wed, 23 Apr 2014, Hans Hagen wrote:

> On 4/22/2014 8:10 PM, Stéphane Goujet wrote:
>>     Please have a look at my example (it is a bit long because it shows
>>  various possibilities) and its result.
>>      When I have not yet done a \defineattribute[myattr],
>>  node.has_attribute
>>  returns 0 when I thought it should return nil.
>>     When I do \defineattribute[...], every attribute seems to get the
>>  same number (1024), but now node.has_attribute returns nil ...
>
> change this is syst-ini.mkiv:
>
> \normalprotected\def\newattribute{\syst_basics_allocate\c_syst_last_allocated_attribute\attribute\attributedef\c_syst_max_allocated_register}

   Thank you, it seems to work much better !

   There is still the problem that "node.has_attribute" does not return 
"nil" when I expect it should, but that is luatex problem (a check 
that a parameter is really an integer should be performed before calling 
lua_tointeger), so I will change mailing-list in order to report it.


Faithfully yours,
   Stéphane Goujet.

[-- Attachment #2: Type: text/plain, Size: 485 bytes --]

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___________________________________________________________________________________

Re: Attributes

[Hans Hagen]

On 4/23/2014 3:07 PM, Stéphane Goujet wrote:
>
>
> On Wed, 23 Apr 2014, Hans Hagen wrote:
>
>> On 4/22/2014 8:10 PM, Stéphane Goujet wrote:
>>>     Please have a look at my example (it is a bit long because it shows
>>>  various possibilities) and its result.
>>>      When I have not yet done a \defineattribute[myattr],
>>>  node.has_attribute
>>>  returns 0 when I thought it should return nil.
>>>     When I do \defineattribute[...], every attribute seems to get the
>>>  same number (1024), but now node.has_attribute returns nil ...
>>
>> change this is syst-ini.mkiv:
>>
>> \normalprotected\def\newattribute{\syst_basics_allocate\c_syst_last_allocated_attribute\attribute\attributedef\c_syst_max_allocated_register}
>>
>
>    Thank you, it seems to work much better !
>
>    There is still the problem that "node.has_attribute" does not return
> "nil" when I expect it should, but that is luatex problem (a check that
> a parameter is really an integer should be performed before calling
> lua_tointeger), so I will change mailing-list in order to report it.

that interface is unlikely to change (e.g. because of performance 
reasons) ... you'd better check at your end

btw, you can try: mynode[123] which is more efficient

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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archive  : http://foundry.supelec.fr/projects/contextrev/
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___________________________________________________________________________________

Re: Attributes

[Stéphane Goujet]

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On Wed, 23 Apr 2014, Hans Hagen wrote:
> On 4/23/2014 3:07 PM, Stéphane Goujet wrote:
>>     There is still the problem that "node.has_attribute" does not return
>>  "nil" when I expect it should, but that is luatex problem (a check that
>>  a parameter is really an integer should be performed before calling
>>  lua_tointeger), so I will change mailing-list in order to report it.
> that interface is unlikely to change (e.g. because of performance reasons)

   Er... well, the other parameter is already checked, with a 
check_isnode() which is heavier than a lua_isnumber() or lua_isnil(). It 
is possible that the former one is not inlined when the other ones are (I 
did not verify either of these hypotheses).

   Anyway, if you do not want to make this change in the code, you should 
change the specification, because now, Luatex reference manual says "It 
returns the value, or, if no match is found, nil", whereas when we supply 
an attribute number which is nil or not a number (therefore it cannot ever 
match), it returns a non-nil value (which, moreover, means "true").
   Something like adding "If id is nil or if id is not an integer, the 
result is unspecified", perhaps.


Goodbye,
   Stéphane.

[-- Attachment #2: Type: text/plain, Size: 485 bytes --]

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___________________________________________________________________________________

Re: Attributes

[Hans Hagen]

On 4/24/2014 1:39 AM, Stéphane Goujet wrote:
> On Wed, 23 Apr 2014, Hans Hagen wrote:
>> On 4/23/2014 3:07 PM, Stéphane Goujet wrote:
>>>     There is still the problem that "node.has_attribute" does not return
>>>  "nil" when I expect it should, but that is luatex problem (a check that
>>>  a parameter is really an integer should be performed before calling
>>>  lua_tointeger), so I will change mailing-list in order to report it.
>> that interface is unlikely to change (e.g. because of performance
>> reasons)
>
>    Er... well, the other parameter is already checked, with a
> check_isnode() which is heavier than a lua_isnumber() or lua_isnil(). It
> is possible that the former one is not inlined when the other ones are
> (I did not verify either of these hypotheses).
>
>    Anyway, if you do not want to make this change in the code, you
> should change the specification, because now, Luatex reference manual
> says "It returns the value, or, if no match is found, nil", whereas when
> we supply an attribute number which is nil or not a number (therefore it
> cannot ever match), it returns a non-nil value (which, moreover, means
> "true").
>    Something like adding "If id is nil or if id is not an integer, the
> result is unspecified", perhaps.

I've added a tracker item and will look at it later (no more changed at 
this moment to the code as we're closing in on release i.e. texlive code 
freeze).

Hans

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: Attributes

[Stéphane Goujet]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 248 bytes --]

On Thu, 24 Apr 2014, Hans Hagen wrote:

> I've added a tracker item and will look at it later (no more changed at this 
> moment to the code as we're closing in on release i.e. texlive code freeze).

   All right.


Goodbye,
   Stéphane.

[-- Attachment #2: Type: text/plain, Size: 485 bytes --]

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