condense() throws "IndexError: list index out of range"

[dan-blank]

Hi there,

I am dabbling with implementing my own DAFSA at the moment, and wondered how a particular sceneario would be represented in an already established library, and got an error. Seeing that this repo is still active and also the one people will most likely find when looking for a DAFSA implementation in python, I did not want to leave without a bug report. Thank you for sharing your work! :)

Reproduction

from dafsa import DAFSA

dafsa = DAFSA(["tapas", "topos"])

# dafsa.condense() # commenting in will cause an error

dafsa.write_figure("test.dot")

What did I expect to happen

A graph of the condensed graph, in particular I assumed that there would only be one edge for 'p' now. (OR: two new collapsed edges, 'apa' and 'opo' - to be honest, I am still a bit shaky when it comes to terminology of DAFSAs/DAWGs)

What happened instead

This error was thrown:

Traceback (most recent call last):
  File "/home/me/bidafsa-visualizer/graphy.py", line 5, in <module>
    dafsa.condense()  # commenting in will cause an error
  File "/home/me/.local/lib/python3.10/site-packages/dafsa/dafsa.py", line 610, in condense
    if self._joining_round() == 0:
  File "/home/me/.local/lib/python3.10/site-packages/dafsa/dafsa.py", line 655, in _joining_round
    edge_info = [edge for edge in edges if edge["target"] == node_id][0]
IndexError: list index out of range

Setup

• OS: Ubuntu 22.04.3 LTS (WSL2)
• Python version: Python 3.10.12
• Library version: dafsa==1.0 (got via pip freeze)