    """
    DictForArgs.py

    See the doc string for the DictForArgs() function.

    Also, there is a test suite in Testing/TestDictForArgs.py
    """

    import re, string

    class DictForArgsError(Exception):
        pass

    def _SyntaxError(s):
        raise DictForArgsError, 'Syntax error: %s' % repr(s)

    def DictForArgs(s):
        """
        Takes an input such as:
                x=3
                name="foo"
                first='john' last='doe'
                required border=3

        And returns a dictionary representing the same. For keys that aren't
        given an explicit value (such as 'required' above), the value is '1'.

        All values are interpreted as strings. If you want ints and floats,
        you'll have to convert them yourself.

        This syntax is equivalent to what you find in HTML and close to other
        ML languages such as XML.

        Returns {} for an empty string.

        The informal grammar is:
            (NAME [=NAME|STRING])*

        Will raise DictForArgsError if the string is invalid.

        See also: PyDictForArgs() and ExpandDictWithExtras() in this module
        """

        s = string.strip(s)

        # Tokenize

        # @@ 2001-09-29 ce: push these outside for better performance
        nameRE   = re.compile(r'\w+')
        equalsRE = re.compile(r'\=')
        stringRE = re.compile(r'''
                        "[^"]+"|
                        '[^']+'|
                        \S+''', re.VERBOSE)    #'
        whiteRE  = re.compile(r'\s+')
        REs = [nameRE, equalsRE, stringRE, whiteRE]

        verbose = 0
        matches = []
        start   = 0
        sLen    = len(s)

        if verbose:
            print '>> DictForArgs(%s)' % repr(s)
            print '>> sLen:', sLen
        while start<sLen:
            for regEx in REs:
                if verbose: print '>> try:', regEx
                match = regEx.match(s, start)
                if verbose: print '>> match:', match
                if match is not None:
                    if match.re is not whiteRE:
                        matches.append(match)
                    start = match.end()
                    if verbose: print '>> new start:', start
                    break
            else:
                _SyntaxError(s)

        if verbose:
            names = []
            for match in matches:
                if match.re is nameRE:
                    name = 'name'
                elif match.re is equalsRE:
                    name = 'equals'
                elif match.re is stringRE:
                    name = 'string'
                elif match.re is whiteRE:
                    name = 'white'
                names.append(name)
                #print '>> match =', name, match
            print '>> names =', names

        # Process tokens

        # At this point we have a list of all the tokens (as re.Match objects)
        # We need to process these into a dictionary.

        dict = {}
        matchesLen = len(matches)
        i = 0
        while i<matchesLen:
            match = matches[i]
            if i+1<matchesLen:
                peekMatch = matches[i+1]
            else:
                peekMatch = None
            if match.re is nameRE:
                if peekMatch is not None:
                    if peekMatch.re is nameRE:
                        # We have a name without an explicit value
                        dict[match.group()] = '1'
                        i = i + 1
                        continue
                    if peekMatch.re is equalsRE:
                        if i+2<matchesLen:
                            target = matches[i+2]
                            if target.re is nameRE  or  target.re is stringRE:
                                value = target.group()
                                if value[0]=="'" or value[0]=='"':
                                    value = value[1:-1]
                                    #value = "'''%s'''" % value[1:-1]
                                    #value = eval(value)
                                dict[match.group()] = value
                                i = i + 3
                                continue
                else:
                    dict[match.group()] = '1'
                    i = i + 1
                    continue
            _SyntaxError(s)

        if verbose: print

        return dict

    from string import letters

    def PyDictForArgs(s):
        """
        Takes an input such as:
                x=3
                name="foo"
                first='john'; last='doe'
                list=[1, 2, 3]; name='foo'

        And returns a dictionary representing the same.

        All values are interpreted as Python expressions. Any error in these
        expressions will raise the appropriate Python exception. This syntax
        allows much more power than DictForArgs() since you can include
        lists, dictionaries, actual ints and floats, etc.

        This could also open the door to hacking your software if the input
        comes from a tainted source such as an HTML form or an unprotected
        configuration file.

        Returns {} for an empty string.

        See also: DictForArgs() and ExpandDictWithExtras() in this module
        """
        s = s.strip()
        if not s:
            return {}

        # special case: just a name
        # meaning: name=1
        # example: isAbstract
        if s.find(' ')==-1 and s.find('=')==-1 and s[0] in letters:
            s += '=1'

        results = {}
        exec s in results

        del results['__builtins__']
        return results

    def ExpandDictWithExtras(dict, key='Extras', delKey=1, dictForArgs=DictForArgs):
        """
        Returns a dictionary with the 'Extras' column expanded by DictForArgs(). For example, given:
            { 'Name': 'foo', 'Extras': 'x=1 y=2' }
        The return value is:
            { 'Name': 'foo', 'x': '1', 'y': '2' }
        The key argument controls what key in the dictionary is used to hold the extra arguments. The delKey argument controls whether that key and its corresponding value are retained.
        The same dictionary may be returned if there is no extras key.
        The most typical use of this function is to pass a row from a DataTable that was initialized from a CSV file (e.g., a spreadsheet or tabular file). FormKit and MiddleKit both use CSV files and allow for an Extras column to specify attributes that occur infrequently.
        """

        if dict.has_key(key):
            newDict = {}
            # We use the following for loop rather than newDict.update()
            # so that the dict arg can be dictionary-like.
            for k, v in dict.items():
                newDict[k] = v
            if delKey:
                del newDict[key]
            newDict.update(dictForArgs(dict[key]))
            return newDict
        else:
            return dict