prozion / rtabtree

R lib to read files in Tabtree format; to generate RDF files from Tabtree

N.B.: This is a “sketch of a sketch” for README, the working lib for Tabtree is currently implemented in Racket language. Transition to R implementation of this library is under way.

Tabtree

Tabtree — is a compact format to write RDF triples. It uses some syntactic sugar to make a work of editing ontologies in the code editor as easy as possible.

Tabs define a level in a hierarchy

(The principle similar to Python)

Tabtree source

Africa
  Kenya
    Elgeyo-Marakwet
      Iten
Europe
  Germany
    Saxony_Land
      Dresden
  Russia
    City_of_Moscow
      Belyaevo
      Zelenograd
    Rostov_region
      Taganrog
        Bogudonia

Files includes

Big ontologies and knowledge graphs is good to divide into several files, regarding the regions of internal cohesion. And then combine them into one resulting Turtle file, ready for uploading to appropriate semtech application.

Here is an example of pasting factories.tree contents into the ‘central’ file called main.tree

Tabtree source

; main.tree

[factories.tree]

Reification

For writing statements like:

‘By March, 2020, the factory produced 2.5% fat strawberry-flavoured yogurt’

Tabtree source

Milk_factory product:Yogurt_strawberry^fat:2.5^date:2020-03

Turtle result

Stmt_506_product_Yogurt_strawberry
  rdf:type rdf:Statement ;
  rdf:subject :Milk_factory ;
  rdf:predicate :product ;
  rdf:object :Yogurt_strawberry ;
  :fat "2.5"^^xsd:decimal ;
  :date "2020-03"^^xsd:date .

Expanding

+ sign propagates the predicate-object pair among all the children of the node, where this form was written:

Tabtree source

cities +a:UrbanPlace
  Beijing
  Shanghaj
  Shenzhen
    Futian_district

Turtle result

:Beijing rdf:type :UrbanPlace .
:Shanghaj rdf:type :UrbanPlace .
:Shenzhen rdf:type :UrbanPlace .
:Futian_district rdf:type :UrbanPlace .

++ Double-plus sign includes predicate-object to the node of origin:

Tabtree source

  Moscow ++a:UrbanPlace
    Zelenograd
      Noviy_Gorod
        Microdistrict_14

Turtle result

:Moscow rdf:type :UrbanPlace .
:Zelenograd rdf:type :UrbanPlace .
:Noviy_Gorod rdf:type :UrbanPlace .
:Microdistrict_14 rdf:type :UrbanPlace .

* Asterisk sign overwrites predicate-object inherited from above, while plain predicate-object without prefixes just adds up to the inherited one:

Tabtree source

  Moscow ++a:UrbanPlace
    Zelenograd
      Stariy_Gorod a:InformallyNamedArea
        Matushkino-Savelki *a:AdministrativeUnit
      Noviy_Gorod
        Microdistrict_14

Turtle result

:Moscow rdf:type :UrbanPlace .
:Zelenograd rdf:type :UrbanPlace .
:Stariy_Gorod rdf:type :UrbanPlace, :InformallyNamedArea .
:Matushkino-Savelki rdf:type :AdministrativeUnit .
:Noviy_Gorod rdf:type :UrbanPlace .
:Microdistrict_14 rdf:type :UrbanPlace .

Tabtree file sections

• namespaces
• classes
• properties
• individuals

Namespaces

Tabtree source <!-- ```tabtree namespaces factory ns:http://example.org/namespaces/factory# geoplace ns:http://example.org/namespaces/geoplace# geo ns:http://www.w3.org/2003/01/geo/wgs84_pos# individuals factory/Taganrog_icecream_factory geo/location:geoplace/Taganrog

![“**Tabtree source**”](man/figures/p1.png?raw=true
"Namespaces example")

**Turtle result**

    @prefix :factory <http://example.org/namespaces/factory#> .
    @prefix :geoplace <http://example.org/namespaces/geoplace#> .
    @prefix :geo <http://www.w3.org/2003/01/geo/wgs84_pos#> .
    
    factory:Taganrog_icecream_factory geo:location geoplace:Taganrog .

## Built-ins

Shorthand, frequently used predicates and classes, like
`rdfs:subClassOf` or `rdfs:range`

**Tabtree source**

City subclass-of:UrbanPlace

**Turtle result**

:City rdfs:subClassOf :UrbanPlace .

### Table of predicate built-ins

| Tabtree shorthand | Compiles to RDF Turtle |
| :---------------: | :--------------------: |
|         a         |        rdf:type        |
|    instance-of    |        rdf/type        |
|    subclass-of    |    rdfs/subClassOf     |
|  subproperty-of   |   rdfs/subPropertyOf   |
|        alt        |       owl/sameAs       |
|        eq         |       owl/sameAs       |
|     eq-class      |  owl/equivalentClass   |
|    eq-property    | owl/equivalentProperty |
|      domain       |      rdfs/domain       |
|       range       |       rdfs/range       |
|         d         |      rdfs/comment      |
|       name        |       rdfs/label       |
|   disjoint-with   |    owl/disjointWith    |

### Table of special classes

These classes are not compiled to something different, and needed to be
declared together with other resources, but in addition, transpiler uses
their names to define the type of object at compilation.

|  Tabtree class  |   Corresponds to    |
| :-------------: | :-----------------: |
|      Year       |    rdfs:Literal     |
|      Date       |      xsd:date       |
|     String      |     xsd:string      |
|     Double      |     xsd:double      |
|      Float      |      xsd:float      |
|     Decimal     |     xsd:decimal     |
| PositiveInteger | xsd:positiveInteger |
|     Integer     |     xsd:integer     |
|     Boolean     |     xsd:boolean     |