Pythonica

This is a temporary page on Pythonica, a symbolic mathematics program for Python. I'm trying to write some bugfixes, so this web page will serve as a small log of what I'm trying.

• September 1, 2001: pythonica-parser-0.05.tar.gz. I actually did most of this work a week ago, but forgot to update the page! The new parser is now munged into the core, and I've commented out the old parser code. I can't say I completely fixed the parser, but it seems to be working better now.
• August 21, 2001: pythonica-parser-0.04.tar.gz. I'm trying to decide a good way of merging the new parser with the rest of the core; I'm thinking of writing a function to convert the AST's that my parser is generating into the "Expr"ession nodes that Pythonica expects. Well, we'll see tomorrow!
• August 19, 2001 (9:15pm): pythonica-parser-0.03.tar.gz. I suddenly realized that recursive descent parsers are a little difficult, wussed out, and pulled out the heavy duty tools (Spark) instead. *grin* The parser seems pretty nice now. Take a look:

  dyoo@einfall:~/pythonica/src$ python PythonicaParser.py
  This is a test harness for PythonicaParser.  Please enter
  expressions at the prompt.  To quit, please type 'quit'.
   
  [PythonicaParser] >>> x*5 - 6x / 2
  -[*[x, 5], *[6, /[x, 2]]]
  [PythonicaParser] >>> 2x
  *[2, x]
  [PythonicaParser] >>> % / 7 + x
  +[/[%, 7], x]
  [PythonicaParser] >>> x + 6
  +[x, 6]
  [PythonicaParser] >>> 2*3+2^2/3
  +[*[2, 3], /[^[2, 2], 3]]
  

  Just a little bit more work, and I think it will be ready to be used with Pythonica.
• August 19, 2001 (Early Morning): pythonica-parser-0.02.tar.gz. Added support for exponentials, as well as implied multiplication, so now this works:

  >>> 2*3+2^2/3
  ['Expression',
   ['Term',
    ['Exponential', ['Factor', 'NUMBER', '2'], None],
    ['Term1', '*', ['Exponential', ['Factor', 'NUMBER', '3'], None], None]],
   ['Expression1',
    '+',
    ['Term',
     ['Exponential',
      ['Factor', 'NUMBER', '2'],
      ['Exponential1', '^', ['Exponential', ['Factor', 'NUMBER', '2'], None]]],
     ['Term1', '/', ['Exponential', ['Factor', 'NUMBER', '3'], None], None]],
    None]]
  

• August 18, 2001: At the moment, I'm trying to fix up the parser. Here's the code I have so far: pythonica-parser-0.01.tar.gz. I'm nowhere near fixing it yet.

Email any questions to dyoo@hkn.eecs.berkeley.edu. Thank you!

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