[WIP; do not merge] Py3 update

[eric-downes]

After fiixng many things in the dependent libraries, I migrated the complete mcdp_posets module to Python 3 with the following changes:

• Update metaclass syntax for Python 3 compatibility
• Convert string formatting to f-strings throughout
• Add hash methods for classes with eq methods
• Fix iterator handling (e.g., zip() returns iterator in Python 3)
• Replace deprecated time.clock() with time.process_time()
• Add explicit imports for functions no longer built-in (functools.reduce)
• Replace sys.maxint with sys.maxsize
• Fix invalid escape sequences in docstrings
• Update print statements in test files

Testing is blocked by dependencies requiring migration (mcdp_library module).

[eric-downes]

Started migrating dependent modules needed to properly test mcdp_posets:

    1. Fixed exception re-raising in several key modules:
       - mcdp_library/library.py
       - mcdp_lang/parse_interface.py
       - mcdp_lang/parse_actions.py
       - mocdp/comp/template_for_nameddp.py
   
   2. Added compatibility for collections.abc module in Python 3.12:
      - Replaced collections.MutableMapping with collections.abc.MutableMapping
      - Replaced collections.Sequence with collections.abc.Sequence
      - Added fallback imports for Python 3.11 and below
   
   3. Added fallback for nose.tools imports that rely on the removed imp module

[eric-downes]

1. Exception Handling Fixes

Fixed Python 2 style exception re-raising by updating:

• Fixed raise e, None, traceback to Python 3's raise e.with_traceback(tb) in multiple files:
  • src/mcdp_library/library.py
  • src/mcdp_lang/parse_interface.py
  • src/mcdp_lang/parse_actions.py
  • src/mocdp/comp/template_for_nameddp.py

2. Collections Module Compatibility

Updated imports to support Python 3.12's removal of ABC classes from collections module:

• Created compatibility imports for:
  • Sequence
  • MutableMapping
  • Mapping
  • Set
  • MutableSet
  • Iterable
• Added the compatibility layer to multiple files:
  • src/mcdp_posets/poset_product.py
  • src/mcdp_lang/pyparsing_bundled.py

3. String/Bytes Handling

Fixed string vs. bytes handling for Python 3:

• Updated the decode_identifier function in src/mcdp_lang/syntax.py to handle both Python 2 and 3
• Created helper functions in pyparsing_compat.py to handle string encoding/decoding
• Fixed parse_wrap function in src/mcdp_lang/parse_actions.py to handle Python 3 strings

4. Print Statement Conversion

• Automatically fixed over 500 instances of Python 2 print statements to use Python 3's print function syntax
• Created fix_print_statements.py script to automate this process

5. Pyparsing Compatibility Layer

Created a comprehensive compatibility layer to handle differences between pyparsing 2.x and 3.x:

• Created src/mcdp_lang/pyparsing_compat.py which:
  • Tries to import from modern pyparsing 3.x first, then falls back to bundled version
  • Handles API differences between versions (camelCase vs snake_case)
  • Provides helper functions for common operations
  • Adds string/bytes conversion utilities
  • Fixed issues with the oneOf function to handle keyword parameters correctly

The library now attempts to use the installed pyparsing 3.x when available, falling back to the bundled version only when necessary.

Known Issues

• The test case syntax_anyof.py still doesn't run due to a memoization issue with unhashable types.

[eric-downes]

1. Fixed Escape Sequences: Addressed invalid escape sequences in strings that would cause warnings or errors in Python 3, fixing 8
   files with issues like \i, \g, . etc.
2. String Formatting: Converted 276 instances of old-style percent-formatting to f-strings for better readability and Python 3
   style.
3. Integer Division: Fixed 39 instances of division that should use integer division (// instead of /) to maintain expected behavior
   in Python 3.
4. Collections Module Imports: Created a script that fixes imports for the collections module, particularly for ABC classes moved to
   collections.abc in Python 3.10+.