FoxySheep 1.1.0

Mathematica parser and translator

This is the Robert Jacobson’s Python implementation of the FoxySheep parser and lexer for Mathematica. It has been stripped down and reorganized a bit.

Examples

When installed, the command-line translator is called foxy-sheep which can convert Mathematica InputForm to Mathematica FullForm without having Mathematica installed: To run the code interactively:

$ foxy-sheep
Enter a Mathematica expression. Enter either an empty line, Ctrl-C, or Ctrl-D to exit.
in:= 1+2
Plus[1,2]
in:=D[4 x^2]
D[Times[4,Power[x,2]]]
in:=
$

To call from Python:

from FoxySheep import FullForm_from_string
print(FullForm_from_string("x^2-3x+4"))
# Prints: Plus[Power[x,2],Times[-1,3,x],4]

For help on foxy-sheep, run foxy-sheep --help.

To see a demo run python demo.py in this directory.

Regenerating the lexer/parser

To change the grammar you’ll need the ANTLR Parser Generator (antlr4), version 4.7.x installed.

To (re)generate the lexer/parser you need to

$ make

The resulting files are placed in FoxySheep/generated.

Files generated by ANTLR4 are assumed to be in a subdirectory called generated containing an empty __init__.py file. See the Makefile for details.

FoxySheepLexer Must Subclass Lexer

In order for the generated antlr4 lexer to work we need to patch the generated Python lexer FoxySheep.lexer.py; The patch file FoxySheep.lexer.py.patch does this. The Makefile target for FoxySheepParser.py contains the patch command.

If patching is not done you’ll get an AttributeError exception in the lexer you try to run it such as through foxy-sheep.

AttributeError: 'FoxySheepLexer' object has no attribute 'checkAdditiveOp'

See Also

FoxySheep