[liblouis-liblouisxml] Re: Scripting language
- From: "John J. Boyer" <john.boyer@xxxxxxxxxxxxxxxxx>
- To: liblouis-liblouisxml@xxxxxxxxxxxxx
- Date: Wed, 16 Oct 2013 09:23:01 -0500
Well, one thing liblouis is failing to do is handle emphasis in UEB
properly. The present algorithm is very difficult to extend or even
debug. What is needed is an extension of the multipass feature that can
look at the typeform parameter. That is basically what the scripting
language is. I'm still working on the design. I'd be happy to
collaborate with someone who has a good deal of experience in language
design and compiler implementation.
If anyone wants to look at the present implementation look for
/* Start of multipass compiler */
in compileTranslationTable.c
John
On Wed, Oct 16, 2013 at 01:52:30PM +0000, Ken Perry wrote:
> Ok but I still don't understand how this would be used. Do you have an
> example of possible emphisised text and the reason you need a script for it?
> I don't understand what liblouis is failing to do now.
>
> Ken
>
> -----Original Message-----
> From: liblouis-liblouisxml-bounce@xxxxxxxxxxxxx
> [mailto:liblouis-liblouisxml-bounce@xxxxxxxxxxxxx] On Behalf Of John J. Boyer
> Sent: Wednesday, October 16, 2013 9:30 AM
> To: liblouis-liblouisxml@xxxxxxxxxxxxx
> Subject: [liblouis-liblouisxml] Re: Scripting language
>
> The scripting language has not yet been extended to cover emphasis.
> Currently it is mostly a higher-level version of the multipass language.
> It will never be a programming language. It's purpose is to deal with the
> enormous variety of ways in which different Braille codes do things.
>
> We already have over a hundrred opcodes, many of them dealing with emphasis.
> The scripting language will enable people to arite rules without altering the
> code of liblouis. The current opcodes such as word begword midward etc. will
> continue to be used where they apply.
>
> John
>
> On Wed, Oct 16, 2013 at 12:05:51PM +0000, Ken Perry wrote:
> > While we are confessing ignorance. I am wondering if John can give an
> > example for things like emphasis and bold and why he thinks we need a
> > scripting language at all. This would help in me understanding what is
> > needed. I found it odd that I had to write a special case context to fix
> > the 18-cell I would think there has to be a opt code way of fixing that if
> > not maybe we need a new opt or rule that takes in to consideration the
> > problem of letters that can be numbers. In the same way I would hate to
> > add a full blown scripting language that we then have to document to fix a
> > problem that could be fixed in an easier way. I am not saying it can be I
> > just am asking what the problem is by example so that we can all look at
> > it. It sounds like most of you know what the problem is but being a new
> > braille guy I am a bit in the dark.
> >
> > Ken
> >
> > -----Original Message-----
> > From: liblouis-liblouisxml-bounce@xxxxxxxxxxxxx
> > [mailto:liblouis-liblouisxml-bounce@xxxxxxxxxxxxx] On Behalf Of Keith
> > Creasy
> > Sent: Wednesday, October 16, 2013 7:41 AM
> > To: liblouis-liblouisxml@xxxxxxxxxxxxx
> > Subject: [liblouis-liblouisxml] Re: Expanding the typeforrm parameter
> >
> > OK, I confess ignorance. What does the "spacing parameter" do?
> >
> >
> >
> > -----Original Message-----
> > From: liblouis-liblouisxml-bounce@xxxxxxxxxxxxx
> > [mailto:liblouis-liblouisxml-bounce@xxxxxxxxxxxxx] On Behalf Of John
> > J. Boyer
> > Sent: Tuesday, October 15, 2013 1:54 PM
> > To: liblouis-liblouisxml@xxxxxxxxxxxxx
> > Subject: [liblouis-liblouisxml] Re: Expanding the typeforrm parameter
> >
> > The reason for not using a larger data type is backward compatibility.
> > That is important. It is also important to preserve the spacing parameter.
> > The typeform and spacing parameters together give 16 bits, of which 4 are
> > already committed. That should be enough to handle colored type, script,
> > etc. the 12 uncommitted bits can be used for anything in the particular
> > document.
> >
> > John
> >
> > On Tue, Oct 15, 2013 at 05:16:38PM +0100, Michael Whapples wrote:
> > > This had also been going through my mind, why not just use a larger
> > > data type?
> > >
> > > I do not know enough about the internals to know what sort of impact
> > > this might have.
> > >
> > > Michael Whapples
> > > On 15/10/2013 16:31, Mesar Hameed wrote:
> > > >I haven't looked at the details of what might be required to do
> > > >this,, but since we are processing more than ascii in more recent
> > > >versions of liblouis, it might be worth considering changing the
> > > >typeform from a char array to a unsigned long int array.
> > > >That would give us a lot of additional bits, without the implicit
> > > >dependancy and complexity of always having to decode both the
> > > >intention by reading the mode and the typeform.
> > > >
> > > >thoughts?
> > > >thanks,
> > > >Mesar
> > > >
> > > >
> > > >
> > > >On Tue 15/10/13,15:04, Ken Perry wrote:
> > > >>My only concern here is how expandable will this be in the future
> > > >>if for example there turns out to be more than 12 needed?
> > > >>
> > > >>Ken
> > > >>
> > > >>-----Original Message-----
> > > >>From: liblouis-liblouisxml-bounce@xxxxxxxxxxxxx
> > > >>[mailto:liblouis-liblouisxml-bounce@xxxxxxxxxxxxx] On Behalf Of John J.
> > > >>Boyer
> > > >>Sent: Monday, October 14, 2013 7:09 AM
> > > >>To: liblouis-liblouisxml@xxxxxxxxxxxxx
> > > >>Subject: [liblouis-liblouisxml] Expanding the typeforrm parameter
> > > >>
> > > >>Let me know if you have comments on the folowing.
> > > >>
> > > >>At present the typeform parameter can handle only four kinds of
> > > >>emphasis, bold, italic, underline and computer Braille. Although
> > > >>this parameter is a character array the high-order bits are used
> > > >>for the ascii numeric code, -x30. This is because at the beginning
> > > >>loblouis functions were called from Visual Basic.
> > > >>
> > > >>However, four types of emphasis are not enough to handle the
> > > >>Braille indicators required by modern textbooks, where it may be
> > > >>necessary to indicate colored type, script, etc.
> > > >>
> > > >>Therefore, I am proposing to use all eight bits of the typeforrm
> > > >>parameter. To preserve backward compatibility an additional bit in
> > > >>the mode parameter will be defined, extTypoeform . Since the
> > > >>spacing parameter is used only by ViewPlus and they may stop using
> > > >>it, I propose to make it an extension of the typeform parameter.
> > > >>This will provide 12 additional ways to indicate things in the
> > > >>text. It will also be controlled by the extTypeform bit.
> > > >>
> > > >>The present system of defining opcodes for things like beginning
> > > >>of phrase, end of phrase, etc for each type of emphasis is
> > > >>unworkable for an extended typeform parameter because it would
> > > >>result in a huge number of opcodes.
> > > >>
> > > >>The present algorithm for handling Braille indicators cannot be
> > > >>expanded for the same reason. Therefore, the
> > > >>correct-context-multipass feature will be extended with a
> > > >>scripting language. The base of this language already exists.
> > > >>
> > > >>John
> > > >>
> > > >>--
> > > >>John J. Boyer; President, Chief Software Developer Abilitiessoft, Inc.
> > > >>http://www.abilitiessoft.com
> > > >>Madison, Wisconsin USA
> > > >>Developing software for people with disabilities
> > > >>
> > > >>For a description of the software, to download it and links to
> > > >>project pages go to http://www.abilitiessoft.com For a description
> > > >>of the software, to download it and links to project pages go to
> > > >>http://www.abilitiessoft.com
> > >
> > > For a description of the software, to download it and links to
> > > project pages go to http://www.abilitiessoft.com
> >
> > --
> > John J. Boyer; President, Chief Software Developer Abilitiessoft, Inc.
> > http://www.abilitiessoft.com
> > Madison, Wisconsin USA
> > Developing software for people with disabilities
> >
> > For a description of the software, to download it and links to project
> > pages go to http://www.abilitiessoft.com For a description of the
> > software, to download it and links to project pages go to
> > http://www.abilitiessoft.com For a description of the software, to
> > download it and links to project pages go to
> > http://www.abilitiessoft.com
>
> --
> John J. Boyer; President, Chief Software Developer Abilitiessoft, Inc.
> http://www.abilitiessoft.com
> Madison, Wisconsin USA
> Developing software for people with disabilities
>
> For a description of the software, to download it and links to project pages
> go to http://www.abilitiessoft.com
> For a description of the software, to download it and links to
> project pages go to http://www.abilitiessoft.com
--
John J. Boyer; President, Chief Software Developer
Abilitiessoft, Inc.
http://www.abilitiessoft.com
Madison, Wisconsin USA
Developing software for people with disabilities
For a description of the software, to download it and links to
project pages go to http://www.abilitiessoft.com
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