Source Code for Module ais.translators

  1  #!/Usr/bin/env python 
  2  __version__ = '$Revision: 2068 $'.split()[1] # See man ident 
  3  __date__ = '$Date: 2006-05-02 08:17:59 -0400 (Tue, 02 May 2006) $'.split()[1] 
  4  __author__ = 'Kurt Schwehr' 
  5   
  6  __doc__=''' 
  7  Codecs to handle encoding to and from BitVectors 
  8   
  9  @requires: U{BitVector<http://cheeseshop.python.org/pypi/BitVector>} 
 10  @requires: U{epydoc<http://epydoc.sourceforge.net/>} > 3.0alpha3 
 11   
 12  @bug: FIX: need some doctests 
 13  @bug: need some asserts 
 14  @todo: maybe decorators? 
 15   
 16  @author: '''+__author__+''' 
 17  @version: ''' + __version__ +''' 
 18  @copyright: 2006 
 19  @var __date__: Date of last svn commit 
 20  @undocumented: __version__ __author__ __doc__ myparser 
 21  ''' 
 22   
 23  # Python standard library 
 24  import sys 
 25  from decimal import Decimal 
 26   
 27  # External libraries 
 28  from BitVector import BitVector 
 29   
 30  # Local 
 31  import aisstring 
 32  import binary 
 33  #import verbosity 
 34  #from verbosity import BOMBASTIC,VERBOSE,TRACE,TERSE,ALWAYS 
 35   
 36   
 37  ###################################################################### 
 38   
 39   
 40  encode={} 
 41  '''use this table to get the functions to go from usable values in python to bitvectors''' 
 42  decode={} 
 43  '''use this table to get the functions to go from bitvectors to usable values in python''' 
 44   
 45   
 46  ###################################################################### 
 47   
 48 -def unsigned_int_enc(val,bitSize): 
 49      '''@rtype: BitVector''' 
 50      bv = BitVector(intVal=val) 
 51      return binary.setBitVectorSize(bv,bitSize) 
 52 -def unsigned_int_dec(bv): 
 53      '''@rtype: int''' 
 54      return int(bv) 
 55   
 56  encode['unsigned int']=unsigned_int_enc 
 57  decode['unsigned int']=unsigned_int_dec 
 58   
 59   
 60 -def int_enc(val,bitSize): 
 61      '''@rtype: BitVector''' 
 62      return binary.bvFromSignedInt(int(val),bitSize) 
 63 -def int_dec(bv): 
 64      '''@rtype: int''' 
 65      return int(binary.signedIntFromBV(bv)) 
 66   
 67  encode['int']=int_enc 
 68  decode['int']=int_dec 
 69   
 70   
 71 -def bool_enc(val,bitSize): 
 72      '''@rtype: BitVector''' 
 73      assert(bitSize==1) 
 74      if val: return BitVector(bitString="0") 
 75      return BitVector(bitString="1") 
 76 -def bool_dec(bv): 
 77      '''@rtype: bool''' 
 78      assert(len(bv)==1) 
 79      if bv[0]==0: return False 
 80      return True 
 81   
 82  encode['bool']=bool_enc 
 83  decode['bool']=bool_dec 
 84   
 85   
 86 -def unsigned_decimal_enc(val,bitSize): 
 87      '''@rtype: BitVector''' 
 88      # FIX: make sure there is no remainder 
 89      bv = BitVector(intVal=int(val)) 
 90      return binary.setBitVectorSize(bv,bitSize) 
 91 -def unsigned_decimal_dec(bv): 
 92      '''@rtype: Decimal''' 
 93      return Decimal(int(bv)) 
 94   
 95  encode['unsigned decimal']=unsigned_decimal_enc 
 96  decode['unsigned decimal']=unsigned_decimal_dec 
 97   
 98   
 99 -def decimal_enc(val,bitSize): 
100      '''@rtype: BitVector''' 
101      # FIX: make sure there is no remainder 
102      return binary.bvFromSignedInt(int(val),bitSize) 
103 -def decimal_dec(bv): 
104      '''@rtype: Decimal''' 
105      return Decimal(binary.signedIntFromBV(bv)) 
106   
107  encode['decimal']=decimal_enc 
108  decode['decimal']=decimal_dec 
109   
110   
111  # floats suck... these have xml encode/decode fields 
112 -def float_enc(val,bitSize): 
113      '''@rtype: BitVector''' 
114      bv = binary.bvFromSignedInt(int(val),bitSize) 
115      return binary.setBitVectorSize(bv,bitSize) 
116 -def float_dec(bv): 
117      '''@rtype: float''' 
118      return float(binary.signedIntFromBV(bv)) 
119   
120  encode['float']=float_enc 
121  decode['float']=float_dec 
122   
123   
124  encode['string']=aisstring.encode 
125  decode['string']=aisstring.decode 
126   
127  ###################################################################### 
128  if __name__=='__main__': 
129      from optparse import OptionParser 
130      myparser = OptionParser(usage="%prog [options]", 
131                              version="%prog "+__version__) 
132      myparser.add_option('--test','--doc-test',dest='doctest',default=False,action='store_true', 
133                          help='run the documentation tests') 
134  #    verbosity.addVerbosityOptions(myparser) 
135      (options,args) = myparser.parse_args() 
136   
137      success=True 
138       
139      if options.doctest: 
140          import os; print os.path.basename(sys.argv[0]), 'doctests ...', 
141          sys.argv= [sys.argv[0]] 
142  #       if options.verbosity>=VERBOSE: sys.argv.append('-v') 
143          import doctest 
144          numfail,numtests=doctest.testmod() 
145          if numfail==0: print 'ok' 
146          else:  
147              print 'FAILED' 
148              success=False 
149   
150      if not success: 
151          sys.exit('Something Failed') 
152