Indentation and grouping proposal

Otto Smith otto at olympus.net
Wed Jun 9 05:11:33 CEST 1999


# Re: Indentation and grouping proposal
#       You don't need to change python to get
#       the functionality you request..

# nips.py
# Non Intuitive Parsing System...
'''
   Here are some routines that allow you to
   write in a style similar to that proposed
   in the: "Indentation and grouping proposal".

   The routines will take ugly unreadable code
   and translate it to simple, neatly indented
   python code.  The constants below set the
   block grouping symbols to '_{' and '}_'
   and the statement separator to ';', but you
   are welcome to change these to anything
   you want.

   Usage is simple:
      parsenips() takes block delimited code
      and converts it into a list of lists format.

      makeright() takes the output of parsnips
      and makes it into python indented code.

Example:

      #####
      import from nips import makeright, parsenips
      ugly = """ if 1<2: _{ print 'Ho ho'; print '1 < 2' }_
                 else: _{ print "surprise";
				 print '2 < 1!!!' }_
             """
      print makeright(parsenips( ugly ))
      #####

Which produces:

if 1<2:
    print 'Ho ho'
    print '1 < 2'
else:
    print 'surprise'
    print '2 < 1!!!'

'''

import string

SPARSEX = "String parse exception"

MYSTART = '_{'
MYEND   = '}_'
MYLINE  = ';'
BADQUOTES  = "'"+'"'

len_mystart = len(MYSTART)
len_myline  = len(MYLINE)

def match(beg, end, str):
    lbeg = len(beg)
    lend = len(end)
    dex = lbeg
    count = 1
    while dex < len(str):
        if str[dex:dex+lend] == end:
            count = count-1
            if count == 0:
                return (str[lbeg:dex],str[dex+lbeg:])
            dex = dex+lend
        elif str[dex:dex+lbeg] == beg:
            count = count+1
            dex = dex+lbeg
        else:
            dex = dex + 1
            continue
        if count < 0:
            raise SPARSEX, 'badly matched quote brackets'
    raise SPARSEX, 'badly matched quote brackets'


def parsenips( str ):
    str = string.strip(str)
    curinst = ''
    statementlist = []
    dex = 0
    while str:
        if str[dex] in BADQUOTES:
            quote = str[dex]
            val, str = match( quote, quote, str[dex:] )
            curinst = curinst+quote+val+quote
            dex = 0
        elif str[dex:dex+len_mystart] == MYSTART:
            if curinst:
                statementlist.append( string.strip(curinst) )
            val, str = match( MYSTART, MYEND, str[dex:] )
            statementlist.append( parsenips(val))
            curinst = ''
            dex = 0
        elif str[dex:dex+len_myline] == MYLINE:
            statementlist.append( string.strip(curinst) )
            str = string.strip(str[dex+len_myline:])
            curinst = ''
            dex = 0
        else:
            curinst = curinst + str[dex]
            dex = dex+1
    if string.strip(curinst):
        statementlist.append( string.strip(curinst))
    return filter(None, statementlist)


SPACER = '    '
def makeright( list, level=0 ):
    pystrings = []
    for val in list:
        if type(val) == type(""):
            pystrings.append( (SPACER*level)+val )
        else:  ## Assert type(val) == ListType
            pystrings.append( makeright(val,level+1) )
    return string.join( pystrings, '\n')

#Otto
#otto at olympus.net





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