'''
mfile.py provides a function, m_to_dict, for parsing a string
consisting of lines from an m-file, each of which simply specifies
a string or numeric variable with its value.  This is not a
complete parser!

'''

## EF 2004/10/04: Added variable substitution, made the
## names arguments optional. Removed dictionary and
## "is_string" arguments.

## EF 2003/12/14: removed is_string argument, added documentation
## and demo.  Added comment removal and parsing of cell arrays
## containing lists of strings (without spaces).

## Original was written in August 2002, on KM cruise, Panama to Honolulu.

import re

def m_to_dict(s, names = None):
   '''Try to fill a dictionary with variables from an m-file.

      s is a string from an m-file
      names is a sequence of variable names to find in the string.
      If names is None, it uses each string to the left of
      an '='.

      The function returns the dictionary, which it creates if
      it did not already exist.

      If a name in names is not found, no error is raised.

   '''

   # Clean out comments and join continued lines.

   lines = s.split('\n')
   cleanlines = []
   for line in lines:
      line = line.split('%', 2)[0]
      i_cont = line.find('...')
      if i_cont >= 0:
         line = line[:i_cont] + ' '
      else:
         line = line + '\n'
      line = line.lstrip()
      line = line.replace(';', '')
      if len(line) > 3:
         cleanlines.append(line)
   s = ''.join(cleanlines)
   d = dict()
   if names is None:
      names = []
      for line in cleanlines:
         fields = line.split('=')
         if len(fields) == 2:
            names.append(fields[0].strip())
   for name in names:
      # Check for a string first:
      pat = r"%s\s*=\s*'(.+)'" % name
      f = re.search(pat, s)
      if f:
         d[name] = f.group(1)
         continue
      # Is it a cell array, with a list of strings?
      pat = r"%s\s*=\s*(\{.*\})" % name
      f = re.search(pat, s)
      if f:
         g = f.group(1).replace('{', '[').replace('}', ']').replace(';', ',')
         d[name] = eval(g)
         continue
      # Is it a number or previously defined variable?
      pat = r"%s\s*=\s*(\S+)" % name
      f = re.search(pat, s)
      if f:
         num_s = f.group(1)
         try:
            n = int(num_s)
         except ValueError:
            try:
               n = float(num_s)
            except ValueError:
               try:
                  n = d[num_s]
               except:
                  continue
         d[name] = n
   return d

if __name__ == "__main__":
   import sys
   s = open(sys.argv[1]).read()
   d =  m_to_dict(s)
   for key, item in d.iteritems():
      print key, '  :  ', item