linked-data-python 0.0.2

The python package "linked-data-python" can rewrite a .ldpy file into an equivalent python code.

Linked-Data Python

The Linked-Data Python package can rewrite a .ldpy file into an equivalent python code.

Installation

You can install the Linked-Data Python

pip install linked-data-python

The Linked-Data Python syntax

The extension "linked-data-python" for Visual Studio Code enables the syntax highlighting for Linked-Data Python source files (extensions .ldpy).

The Linked-Data Python grammar only uses grammar rules supported by MicroPython 1.18, and adds support for Linked Data languages primitives and constructs:

• prefix declaration statements: @prefix ex: <http://example.org/> .
• base declaration statements: @base <http://example.org/> .
• IRIs: `http://example.org/
• Prefixed names: ex:Person
• RDF literals: "hello"^^xsd:string, f"hello {world}"@en
• RDF graphs: g{ ex:Person a owl:Class ; rdfs:label "Person"@en }

Furthermore, it allows:

• formatted IRIs: f<http://example/org/{ id }/>
• formatted nodes in RDF graphs: f{ ex:Person ex:age ?{ age } }

Example programs are available in the examples folder of the source code repository.

How to use

The Linked-Data Python package is a command line application, name ldpy. It can also be run as python -m ldpy.

$ python -m ldpy -h
usage: __main__.py [-h] [-l] [-p] [-d] [-s] [-w] [-x] file

Rewrite a .ldpy file into an equivalent python code.

positional arguments:
  file                  the file to rewrite

optional arguments:
  -h, --help            show this help message and exit
  -l, --debug-lexer     print the lexer output
  -p, --debug-parser    print the parser output
  -d, --diagnose-syntax
                        diagnose the ambiguities in the syntax
  -s, --silent          do not display the output code
  -w, --write-output    write the output python code with the .py extension
  -x, --execute         execute the output cod

You can also run a transformation in your own Python code, by importing from the ldpy package:

from ldpy import *
input_stream = FileStream(file) # or = InputStream(string)
lexer = LDPythonLexer(input_stream)
stream = MultiChannelTokenStream(lexer)
parser = LDPythonParser(stream)
tree = parser.file_input()
if parser.getNumberOfSyntaxErrors() != 0:
    raise Exception("Exception while parsing the input")
output = IndentedStringWriter()
visitor = LDPythonRewriter(output)
visitor.visit(tree)
print("\noutput:\n" + output.getvalue())

Run from the source code

1. Dependencies

# cd ldpy
pip install -r requirements.txt

2. Generate the parser

Generate the SWPythonLexer, SWPythonParser, and SWPythonVisitor using ANTLR4:

# cd ldpy
antlr4 -o ldpy/rewriter/antlr -package ldpy.rewriter.antlr -Xexact-output-dir -Dlanguage=Python3 -visitor -no-listener grammars/LDPython.g4

Release Notes

0.0.1

Initial release of the Linked-Data Python package