About the parser

Process

The complete parsing procedure has 3 phases.

1. The LDF is passed through lark-parser where it’s converted into a syntax tree.

2. The tree is transformed into a Python dictionary.

3. The dictionary is converted into Python objects.

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Using the parser

Parsing into dictionary

The library allows the conversion of LDF into a Python dictionary. The dictionary’s layout can be interpreted through the LDFTransformer class or by exporting an LDF into JSON format. The field names and structure try to be very similar to the ones in the LDF specification.

ldf = ldfparser.parse_ldf_to_dict('network.ldf')

print(ldf['speed'])
>>> 19200
print(ldf['nodes']['slaves'])
>>> ['LSM', 'RSM']

If you’re just looking to convert into JSON so that some other tool can interpret it then have a look at export command in the CLI.

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Parsing into LIN objects

After converting the LDF into a dictionary the parser maps these values into Python objects that can be used for easier data access as well as traversal through the links between objects.

ldf = ldfparser.parse_ldf('network.ldf')
print(ldf.get_baudrate())
>>> 19200
for node in ldf.get_slaves():
  print(node.name)
>>> 'LSM'
>>> 'RSM'