In wikipedia (and in MPEG-7 standard), it says:
DDL (Description Definition Language) is part of the MPEG-7 standard. It gives an important set of tools for the users to create their own Description Schemes (DSs) and Descriptors (Ds). DDL defines the syntax rules to define, combine, extend and modify Description Schemes and Descriptors.
But I can't found any tutorial about how to use DDL to modify existing DS or D. Any example?
Related
If I were to want to create a new programming language, is there a specific file format or extension used to define the grammar of this new language? Or should I just use a plain text file?
What you are looking for might be a metasyntax notation, sometimes also called "formal grammar".
A common notation to describe at least certain types of formal languages is Extended Backus-Naur Form. It defines the grammar by means of "production rules" that gradually expand a "start symbol" into any valid expressions in the described language.
This format is, however, mainly a notation (i.e. it describes how you write down the language description, even when you're writing on paper). It is not so much a "file format" in the sense that there would be a standard extension for it.
Is there a convention for naming Scheme libraries? I am thinking of using reverse domain name notation, similar to Java's convention. For example, (define-library (com example mylib) ...) or (define-library (com.example.mylib) ...). Is there a general guideline for naming Scheme libraries (other than avoiding the use of scheme and srfi as the first identifier in the library name)?
http://www.r6rs.org references "Revised6 Report on the Algorithmic Language Scheme — Non-Normative Appendices"
PDF | HTML
Appendix G addresses this issue:
Programmers should choose names for distributed libraries that do not collide with other libraries’ names. This appendix suggests a convention for generating unique library names, similar to the convention for Java [1].
A unique library name can be formed by associating the library with an Internet domain name, such as mit.edu. The lower-case components of the domain are reversed to form a prefix for the library name. Adding further name components to establish a hierarchy may be advisable, depending on the size of the organization associated with the domain name, the number of libraries to be distributed from it, and other organizational properties or conventions associated with the library.
Programmers should use library names that are suitable for use as part of file names. Special characters in domain names that do not fit conventions of commonly used file systems should be replaced by hyphens or suitable “escape sequences” that, as much as possible, are suitable for avoiding collisions. Here are some examples for possible library names according to this convention:
(edu mit swiss cheese)
(de deinprogramm educational graphics turtle)
(com pan-am booking passenger)
The name of a library does not necessarily indicate an Internet address where the package is distributed.
When creating a FHIR ValueSet using ALL codes of a small externally defined code list, which would be more appropriate (and indeed correct per the FHIR specification) - a composition or an inline codeSystem?
As an example, creating a ValueSet from the following code list:
http://www.datadictionary.nhs.uk/data_dictionary/attributes/e/end/ethnic_category_code_de.asp
Would there be advantages/disadvantages of using either method?
Inline definition of a code system is used when the code system and value set are synonymous - you're inventing codes and saying the value set contains all of them. Places this occurs are when we're defining structural codes for FHIR (ones that we'll be maintaining rather than external organization) or for things like Questionnaires where the codes might be specific to that particular questionnaire. In general, inventing your own code system isn't encouraged because it's less likely people will recognize it. It's better to draw codes from standardized code systems, be those international (like SNOMED, LOINC, ICD9, etc.) or national or even organization-maintained code systems.
I just discovered OWL and Protege. Upon reading through this reference page (which I quote below), I am left wondering whether it is possible to not use the abstract OWL syntax, and rather to write in DL syntax. My background is in logic, so it sounds like it would be more fun even if I would have to translate the ontologies later (though I am sure there must be applications to do this--besides, don't reasoners use DL?).
If it is possible, what configuration of settings should I use in Protege (or other software of your suggestion) in order to do this? I suspect it's not possible, but I want to be sure, as I see no good reason for this other than the awkwardness of special symbols.
EDIT: If it is NOT possible, how exactly are DL languages used?
OWL DL is the description logic SHOIN with support of data values, data types
and datatype properties, i.e., SHOIN(D), but since OWL is based on RDF(S), the
terminology slightly differs. ... For description of OWL ontology or knowledge
base, the DL syntax can be used. There is an "abstract" LISP-like syntax
defined that is easier to write in ASCII character set.
Here's a very brief working example of the two syntax styles for the same data.
don't reasoners use DL?
Not necessarily. They use all kinds of logics, some of which are DLs, some are not.
If it is possible, what configuration of settings should I use in Protege (or other software of your suggestion) in order to do this?
I'm pretty sure there is no such pluggin for Protégé. But if you really want some fun, use a text editor and write your ontology by hand. There are many syntaxes you can use: the functional syntax, the OWL/XML syntax, the RDF/XML syntax are all normative. In addition, you can use the Manchester syntax, Turtle, N-Triples, JSON-LD, that will be future recommendations for writing RDF (and therefore OWL). Or the more exotic RDF/JSON, HDT. Or again, more "powerful" syntaxes like Notation3, TriG, TriX, NQuads. Plenty of fun!
In any case, if you would like to write in the DL syntax, you would need to use special Unicode characters or special commands like in LaTeX for instance. And the parser that deals with it would have to read those characters or commands. Not ideal if you are programming. But you can always use the DL syntax in your writings.
BTW, the current standard Web Ontology Language is OWL 2. Its DL variant (viz., OWL 2 DL) is based on the even more irresistible SROIQ.
I want to create a "terminology" section with definitions for terms that I'm using such that every time I use the terms in this terminology section, a link is created that points to the definition.
Currently, the best I can think up is:
.. |flavor| replace:: `:ref:flavor`
.. _flavor:
flavor
------
blah blah blah
Then later, in the other text I have to do:
''' This is a usage of the word |flavor|.'''
I find the above syntax to be very cumbersome. I know I could use yet another layer of scripting or m4 to auto-generate this syntax, but I'm hoping there's a better way..
Not so different, but you can use:
.. glossary::
This directive must contain a reST definition list with terms and definitions. The definitions will then be referencable with the 'term' role.
:term:
Reference to a term in the glossary. The glossary is created using the glossary directive containing a definition list with terms and definitions. It does not have to be in the same file as the term markup, for example the Python docs have one global glossary in the glossary.rst file.
If you use a term that’s not explained in a glossary, you’ll get a warning during build.
[pasted from official sphinx documentation]