This is an early version of Bruker's TOPAS macro language parser, used by commercial and academic TOPAS code. We have compared two canonical parsing approaches for Python, lark vs. pyparsing, and ended up with pyparsing being more convenient for debugging.

pip install .

Install package with optional dependencies with pip install -e .[lint,test,release]

Parse a TOPAS macro language node with:

echo "xdd { 42 }" | topas2json - | json2topas -

More specifically, parse TOPAS input and convert it to JSON with:

import json
from pytopas import TOPASParser

src = "a(b,c)"

tree = TOPASParser.parse(src)
print(json.dumps(tree))

Convert parser's JSON-encoded TOPAS code back into the TOPAS input format:

import json
from pytopas import TOPASParseTree

input_json = """
["topas",
  ["formula",
    ["func_call", "a",
      ["formula", ["p", {"n": ["parameter_name", "b"]}]],
      ["formula", ["p", {"n": ["parameter_name", "c"]}]]]]]
"""
serialized = json.loads(input_json)
src = TOPASParser.reconstruct(serialized)
print(src)

After installing the package, two command line utilities will be available.

usage: topas2json [-h] [--ignore-warnings] file

Parse TOPAS input and output JSON

positional arguments:
  file               Path to TOPAS file or '-' for stdin input

options:
  -h, --help         show this help message and exit
  --ignore-warnings  Don't print parsing warnings

usage: json2topas [-h] file

Parse JSON input and output TOPAS

positional arguments:
  file        Path to JSON file or '-' for stdin input

options:
  -h, --help  show this help message and exit

Author Sergey Korolev, Tilde Materials Informatics

Copyright 2023 BASF SE

BSD 3-Clause