Re: [NTG-context] Access current element in xmlsetsetup via xml.expressions
Dear Hans,
that is really great. Thank's a lot. Ill check the next beta and try to
wikifiy (maybe I need further help for that)
Achim
-Ursprüngliche Nachricht-
Von: ntg-context Im Auftrag von Hans Hagen
Gesendet: Mittwoch, 2. Oktober 2019 18:53
An: mailing list for ConTeXt users ; mf
Betreff: Re: [NTG-context] Access current element in xmlsetsetup via
xml.expressions
On 10/2/2019 12:32 PM, mf wrote:
> The answer is in lxml-lpt.lua, where built-in expressions are defined.
> You need a good knowledge of LPEG that i miss.
>
> Some built-in expressions get the current element as first argument,
> like count() or child() (lines 1300-1307 of lxml-lpt.lua):
>
> expressions.child = function(e,pattern)
> return applylpath(e,pattern) -- todo: cache end
>
> expressions.count = function(e,pattern) -- what if pattern == empty or
> nil
> local collected = applylpath(e,pattern) -- todo: cache
> return pattern and (collected and #collected) or 0 end
>
> Some other expressions use a template that passes the "list", "ll", "l"
> and "order" arguments you find cited in the XML manual §4.1 "Path
> expressions - Expressions and filters".
> These are the lines 738-743 in lxml-lpt.lua:
>
> local template_e = [[
> local expr = xml.expressions
> return function(list,ll,l,order)
> return %s
> end
> ]]
>
> That template is used by the function that registers a new expression
> (lines 807-812 in lxml-lpt.lua):
>
> local function register_expression(expression)
> local converted = lpegmatch(converter,expression)
> local runner = load(format(template_e,converted))
> runner = (runner and runner()) or function()
> errorrunner_e(expression,converted) end
> return { kind = "expression", expression = expression, converted
> = converted, evaluator = runner } end
>
> Anyway i could not find a way to define an expression with a function
> like this:
>
> xml.expressions.myexpr( ... )
>
> that gets access to those arguments.
>
> The only arguments it gets are the ones you specify in your LPATH
> expressions; AFAIK they are attributes values -- with the @attr syntax
> -- and strings.
Live is complex isn't it? The problem, is that we also support the normal path
expressions which in retrospect maybe was a bad idea ...
better be explicit. Strings without quotes are actually intercepted as element
references (just like the @ is).
So, I added a few extra accessors:
\startbuffer[text]
A sup 1
B sub 1
C sup 2
D sub 2
E sup 3
F sup 4
G sup 5
H sub 5
I sup 6 \stopbuffer
\startluacode
function xml.expressions.MyCheck(list,position,what)
-- print("list",list)
-- print("position",position)
-- print("what",what)
local n = list[position+1]
return n and n.at.style == what
end
\stopluacode
\enabletrackers[lxml.*]
\startxmlsetups xml:textsetups
\xmlsetsetup{#1}{para|inline}{xml:*}
% with a helper:
% \xmlsetsetup{#1}{inline[@style='sup' and
MyCheck(list(),position(),"sub")]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and
MyCheck(list(),position(),"sup")]}{xml:supsup}
% rather verbose, we *need* to use ['at'] and not .at
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
list()[position()+1]['at']['style']=='sub')]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
list()[position()+1]['at']['style']=='sup')]}{xml:supsup}
% also ok
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style')=='sub')]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style')=='sup')]}{xml:supsup}
% direct checking
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style','sub'))]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style','sup'))]}{xml:supsup}
% shorter
\xmlsetsetup{#1}{inline[@style='sup' and
(attribute(list()[position()+1],'style','sub'))]}{xml:supsub}
\xmlsetsetup{#1}{inline[@style='sup' and
(attribute(list()[position()+1],'style','sup'))]}{xml:supsup}
\stopxmlsetups
\xmlregistersetup{xml:textsetups}
\startxmlsetups xml:para
\xmlflush{#1}\par
\stopxmlsetups
\startxmlsetups xml:supsub
\color[red]{\xmlflush{#1}}
\stopxmlsetups
\startxmlsetups xml:supsup
\color[blue]{\xmlflush{#1}}
\stopxmlsetups
\startxmlsetups xml:inline
\color[green]{\xmlflush{#1}}
\stopxmlsetups
\starttext
\xmlprocessbuffer
Re: [NTG-context] Access current element in xmlsetsetup via xml.expressions
On 10/2/2019 12:32 PM, mf wrote:
The answer is in lxml-lpt.lua, where built-in expressions are defined.
You need a good knowledge of LPEG that i miss.
Some built-in expressions get the current element as first argument,
like count() or child() (lines 1300-1307 of lxml-lpt.lua):
expressions.child = function(e,pattern)
return applylpath(e,pattern) -- todo: cache
end
expressions.count = function(e,pattern) -- what if pattern == empty or nil
local collected = applylpath(e,pattern) -- todo: cache
return pattern and (collected and #collected) or 0
end
Some other expressions use a template that passes the "list", "ll", "l"
and "order" arguments you find cited in the XML manual §4.1 "Path
expressions - Expressions and filters".
These are the lines 738-743 in lxml-lpt.lua:
local template_e = [[
local expr = xml.expressions
return function(list,ll,l,order)
return %s
end
]]
That template is used by the function that registers a new expression
(lines 807-812 in lxml-lpt.lua):
local function register_expression(expression)
local converted = lpegmatch(converter,expression)
local runner = load(format(template_e,converted))
runner = (runner and runner()) or function()
errorrunner_e(expression,converted) end
return { kind = "expression", expression = expression, converted =
converted, evaluator = runner }
end
Anyway i could not find a way to define an expression with a function
like this:
xml.expressions.myexpr( ... )
that gets access to those arguments.
The only arguments it gets are the ones you specify in your LPATH
expressions; AFAIK they are attributes values -- with the @attr syntax
-- and strings.
Live is complex isn't it? The problem, is that we also support the
normal path expressions which in retrospect maybe was a bad idea ...
better be explicit. Strings without quotes are actually intercepted as
element references (just like the @ is).
So, I added a few extra accessors:
\startbuffer[text]
A sup 1
B sub 1
C sup 2
D sub 2
E sup 3
F sup 4
G sup 5
H sub 5
I sup 6
\stopbuffer
\startluacode
function xml.expressions.MyCheck(list,position,what)
-- print("list",list)
-- print("position",position)
-- print("what",what)
local n = list[position+1]
return n and n.at.style == what
end
\stopluacode
\enabletrackers[lxml.*]
\startxmlsetups xml:textsetups
\xmlsetsetup{#1}{para|inline}{xml:*}
% with a helper:
% \xmlsetsetup{#1}{inline[@style='sup' and
MyCheck(list(),position(),"sub")]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and
MyCheck(list(),position(),"sup")]}{xml:supsup}
% rather verbose, we *need* to use ['at'] and not .at
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
list()[position()+1]['at']['style']=='sub')]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
list()[position()+1]['at']['style']=='sup')]}{xml:supsup}
% also ok
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style')=='sub')]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style')=='sup')]}{xml:supsup}
% direct checking
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style','sub'))]}{xml:supsub}
% \xmlsetsetup{#1}{inline[@style='sup' and (position() < last() and
attribute(list()[position()+1],'style','sup'))]}{xml:supsup}
% shorter
\xmlsetsetup{#1}{inline[@style='sup' and
(attribute(list()[position()+1],'style','sub'))]}{xml:supsub}
\xmlsetsetup{#1}{inline[@style='sup' and
(attribute(list()[position()+1],'style','sup'))]}{xml:supsup}
\stopxmlsetups
\xmlregistersetup{xml:textsetups}
\startxmlsetups xml:para
\xmlflush{#1}\par
\stopxmlsetups
\startxmlsetups xml:supsub
\color[red]{\xmlflush{#1}}
\stopxmlsetups
\startxmlsetups xml:supsup
\color[blue]{\xmlflush{#1}}
\stopxmlsetups
\startxmlsetups xml:inline
\color[green]{\xmlflush{#1}}
\stopxmlsetups
\starttext
\xmlprocessbuffer{main}{text}{}
\stoptext
In the next beta. Now, who is going to wikify this ...
Hans
-
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-
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Re: [NTG-context] Access current element in xmlsetsetup via xml.expressions
The answer is in lxml-lpt.lua, where built-in expressions are defined.
You need a good knowledge of LPEG that i miss.
Some built-in expressions get the current element as first argument,
like count() or child() (lines 1300-1307 of lxml-lpt.lua):
expressions.child = function(e,pattern)
return applylpath(e,pattern) -- todo: cache
end
expressions.count = function(e,pattern) -- what if pattern == empty or nil
local collected = applylpath(e,pattern) -- todo: cache
return pattern and (collected and #collected) or 0
end
Some other expressions use a template that passes the "list", "ll", "l"
and "order" arguments you find cited in the XML manual §4.1 "Path
expressions - Expressions and filters".
These are the lines 738-743 in lxml-lpt.lua:
local template_e = [[
local expr = xml.expressions
return function(list,ll,l,order)
return %s
end
]]
That template is used by the function that registers a new expression
(lines 807-812 in lxml-lpt.lua):
local function register_expression(expression)
local converted = lpegmatch(converter,expression)
local runner = load(format(template_e,converted))
runner = (runner and runner()) or function()
errorrunner_e(expression,converted) end
return { kind = "expression", expression = expression, converted =
converted, evaluator = runner }
end
Anyway i could not find a way to define an expression with a function
like this:
xml.expressions.myexpr( ... )
that gets access to those arguments.
The only arguments it gets are the ones you specify in your LPATH
expressions; AFAIK they are attributes values -- with the @attr syntax
-- and strings.
Best wishes,
Massi
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Re: [NTG-context] Access current element in xmlsetsetup via xml.expressions
> On 1 Oct 2019, at 21:24, ac...@jander.de wrote:
>
> Hello,
> I’m trying to build an xmlsetsetup with an own lua function. XML in MKIV says
> on pg. 33:
> You can also use normal Lua functions as long as you make sure that you pass
> the right arguments.
> There are a few predefined variables available inside such functions.
> list table the list of matches
> l number the current index in the list of matches
> ll element the current element that matched
> order number the position of the root of the path
>
> But I can’t figure out how to get access to list, ll etc.
Neither can I :(
Taco
> My MWE (only for testing the access, is always true):
>
> \startbuffer[text]
> Dies ist ein xxx style="sub">zwei noch ein sup
> Testsub
> \stopbuffer
> %\enabletrackers[xml.parse,xml.path]
>
> \startluacode
> function xml.expressions.nextnodeatt(e)
> inspect(e)
> inspect(ll)
> return('sub')
> end
> \stopluacode
>
> \startxmlsetups xml:textsetups
> \xmlsetsetup{#1}{*}{+}
> \xmlsetsetup{#1}{para}{xml:*}
>
> \xmlsetsetup{#1}{inline[@style='sup'][xml.expressions.nextnodeatt(ll)=='sub']}{xml:sub}
> \stopxmlsetups
>
> \xmlregistersetup{xml:textsetups}
>
> \startxmlsetups xml:para
> \xmlflush{#1}\par
> \stopxmlsetups
>
> \startxmlsetups xml:sub
> \color[red]{\xmlflush{#1}}
> \stopxmlsetups
>
>
> \starttext
> \xmlprocessbuffer{main}{text}{}
> \stoptext
>
> Thanks in advance,
> Achim
> ___
> 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://context.aanhet.net
> archive : https://bitbucket.org/phg/context-mirror/commits/
> wiki : http://contextgarden.net
> ___
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Elvenkind BV
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[NTG-context] Access current element in xmlsetsetup via xml.expressions
Hello,
I'm trying to build an xmlsetsetup with an own lua function. XML in MKIV
says on pg. 33:
You can also use normal Lua functions as long as you make sure that you pass
the right arguments.
There are a few predefined variables available inside such functions.
list table the list of matches
l number the current index in the list of matches
ll element the current element that matched
order number the position of the root of the path
But I can't figure out how to get access to list, ll etc.
My MWE (only for testing the access, is always true):
\startbuffer[text]
Dies ist ein xxxzwei noch ein sup
Testsub
\stopbuffer
%\enabletrackers[xml.parse,xml.path]
\startluacode
function xml.expressions.nextnodeatt(e)
inspect(e)
inspect(ll)
return('sub')
end
\stopluacode
\startxmlsetups xml:textsetups
\xmlsetsetup{#1}{*}{+}
\xmlsetsetup{#1}{para}{xml:*}
\xmlsetsetup{#1}{inline[@style='sup'][xml.expressions.nextnodeatt(ll)=='sub'
]}{xml:sub}
\stopxmlsetups
\xmlregistersetup{xml:textsetups}
\startxmlsetups xml:para
\xmlflush{#1}\par
\stopxmlsetups
\startxmlsetups xml:sub
\color[red]{\xmlflush{#1}}
\stopxmlsetups
\starttext
\xmlprocessbuffer{main}{text}{}
\stoptext
Thanks in advance,
Achim
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