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      1 #!/usr/local/bin/python
      2 # yply.py
      3 #
      4 # Author: David Beazley (dave (at] dabeaz.com)
      5 # Date  : October 2, 2006
      6 #
      7 # Converts a UNIX-yacc specification file into a PLY-compatible
      8 # specification.   To use, simply do this:
      9 #
     10 #   % python yply.py [-nocode] inputfile.y >myparser.py
     11 #
     12 # The output of this program is Python code. In the output,
     13 # any C code in the original file is included, but is commented.
     14 # If you use the -nocode option, then all of the C code in the
     15 # original file is discarded.
     16 #
     17 # Disclaimer:  This just an example I threw together in an afternoon.
     18 # It might have some bugs.  However, it worked when I tried it on
     19 # a yacc-specified C++ parser containing 442 rules and 855 parsing
     20 # states.
     21 #
     22 
     23 import sys
     24 sys.path.insert(0, "../..")
     25 
     26 import ylex
     27 import yparse
     28 
     29 from ply import *
     30 
     31 if len(sys.argv) == 1:
     32     print("usage : yply.py [-nocode] inputfile")
     33     raise SystemExit
     34 
     35 if len(sys.argv) == 3:
     36     if sys.argv[1] == '-nocode':
     37         yparse.emit_code = 0
     38     else:
     39         print("Unknown option '%s'" % sys.argv[1])
     40         raise SystemExit
     41     filename = sys.argv[2]
     42 else:
     43     filename = sys.argv[1]
     44 
     45 yacc.parse(open(filename).read())
     46 
     47 print("""
     48 if __name__ == '__main__':
     49     from ply import *
     50     yacc.yacc()
     51 """)
     52