name = node.tagName

    if name.startswith('_') and name in funcs:

        try:

            xml_dom.replace_with_text(node, value)

        except Exception, e: # also catch non-wrapped exceptions (XML func bugs)

            # Save in case another exception raised, overwriting sys.exc_info()

#### General

    '''Used to "comment out" an XML subtree'''

    return None

funcs['_ignore'] = _ignore

#### Conditionals

    items = dict(items)

    try:

        left = items['left']

    return util.bool2str(left == right)

funcs['_eq'] = _eq

    items = dict(items)

    try:

        cond = items['cond']

#### Combining values

    items = list(items)

    items.sort()

    try: return items[0][1] # value of lowest-numbered item

    except IndexError: return None # input got removed by e.g. FormatException

funcs['_alt'] = _alt

    items = list(conv_items(strings.ustr, items))

        # get *once* from iter, check types

    items.sort()

    return maps.merge_values(*[v for k, v in items])

funcs['_merge'] = _merge

    items = dict(conv_items(strings.ustr, items))

        # get *once* from iter, check types

    value = items.get('value', None)

#### Transforming values

    '''Collapses a subtree if the "value" element in it is NULL'''

    items = dict(items)

    try: require = cast(strings.ustr, items['require'])

types_by_name = {None: strings.ustr, 'str': strings.ustr, 'float': float}

    items = dict(conv_items(strings.ustr, items))

    try: null = items['null']

    except KeyError, e: raise SyntaxError(e)

    if new_value == '*': new_value = value # '*' means keep input value the same

    return new_value

    '''See repl()

    @param items

        <last_entry> Value

    return util.none_if(repl(dict(items), value), u'') # empty value means None

funcs['_map'] = _map

    items = conv_items(strings.ustr, items) # get *once* from iter, check types

    value = pop_value(items)

    if value == None: return None # input is empty

#### Quantities

    items = conv_items(strings.ustr, items) # get *once* from iter, check types

    value = pop_value(items)

    if value == None: return None # input is empty

    if start == '' and range_sep == '-': return default # negative number

    return tuple(d.strip() for d in (start, end))

    items = dict(conv_items(strings.ustr, items))

    try: value = items['value']

    except KeyError: return None # input is empty

    return parse_range(value)[0]

funcs['_rangeStart'] = _rangeStart

    items = dict(conv_items(strings.ustr, items))

    try: value = items['value']

    except KeyError: return None # input is empty

    return parse_range(value)[1]

funcs['_rangeEnd'] = _rangeEnd

    items = dict(conv_items(float, items))

    from_ = items.get('from', None)

    to = items.get('to', None)

    return str(to - from_)

funcs['_range'] = _range

    count = 0

    sum_ = 0.

    for name, value in conv_items(float, items):

            ' allowed for ratio scale data '

            '(see <http://en.wikipedia.org/wiki/Coefficient_of_variation>)')

    try: name, value = items.next()

    except StopIteration: return None

    if re.match('^(?i)CV *\d+$', value): raise FormatException(CvException())

#### Dates

    items = dict(conv_items(strings.ustr, items))

        # get *once* from iter, check types

    try: str_ = items['date']

    except ValueError, e: raise FormatException(e)

funcs['_date'] = _date

    items = dict(conv_items(strings.ustr, items))

    try: value = items['value']

    except KeyError: return None # input is empty

    return dates.parse_date_range(value)[0]

funcs['_dateRangeStart'] = _dateRangeStart

    items = dict(conv_items(strings.ustr, items))

    try: value = items['value']

    except KeyError: return None # input is empty

name_parts_slices = dict(_name_parts_slices_items)

name_parts = [name for name, slice_ in _name_parts_slices_items]

    items = dict(items)

    parts = []

    for part in name_parts:

    return ' '.join(parts)

funcs['_name'] = _name

    out_items = []

    for part, value in items:

        try: slice_ = name_parts_slices[part]

        except KeyError, e: raise SyntaxError(e)

        out_items.append((part, ' '.join(value.split(' ')[slice_])))

funcs['_namePart'] = _namePart

#### Angles

    '''Converts a compass direction (N, NE, NNE, etc.) into a degree heading'''

    items = dict(conv_items(strings.ustr, items))

    try: value = items['value']

#### Paths

    items = dict(items)

    try:

        next = cast(strings.ustr, items['next'])