def demo():
"""
A demonstration that shows the output of several different
tokenizers on the same string.
"""
from nodebox_linguistics_extended.parser.nltk_lite import tokenize
# Define the test string.
s = "Good muffins cost $3.88\nin New York. Please buy me\ntwo of them.\n\nThanks."
print 'Input text:'
print ` s `
print
print 'Tokenize using whitespace:'
_display(tokenize.whitespace(s))
print
print 'Tokenize sequences of alphanumeric characters:'
_display(tokenize.regexp(s, pattern=r'\w+', gaps=False))
print
print 'Tokenize sequences of letters and sequences of nonletters:'
_display(tokenize.wordpunct(s))
print
print 'Tokenize by lines:'
_display(tokenize.line(s))
print
print 'Tokenize by blank lines:'
_display(tokenize.blankline(s))
print
print 'A simple sentence tokenizer:'
_display(tokenize.regexp(s, pattern=r'\.(\s+|$)', gaps=True))
print
def _parse(s):
rx_pattern = re.compile(
r"""
\(CODE .*\)
|\(ID .*\d\)
""", re.VERBOSE | re.UNICODE)
s = re.sub(rx_pattern, '', s)
s = split(s, '\n')
fullPhrase = ""
# loop through the sentences and parse each sentence
# every time a new sentence marker is found
for sent in s:
if list(tokenize.regexp(sent, r'^\(')) != []:
fullPhrase = _strip_spaces(fullPhrase)
if fullPhrase != "":
yield fullPhrase
fullPhrase = sent
else:
fullPhrase += sent
# Get the last of the buffer and output a yield
fullPhrase = _strip_spaces(fullPhrase)
if fullPhrase != "":
yield fullPhrase
def parse(self, p_string):
"""
Parses a string and stores the resulting hierarchy of "domains"
"hierarchies" and "tables"
For the sake of NLP I've parsed the string using the nltk_lite
context free grammar library.
A query is a "sentence" and can either be a domain, hierarchy or a table.
A domain is simply a word.
A hierarchy is expressed as "domain/domain"
A table is exressed as "table(sentence, sentence, sentence)"
Internally the query is represented as a nltk_lite.parse.tree
Process:
1. string is tokenized
2. develop a context free grammar
3. parse
4. convert to a tree representation
"""
self.nltktree = None
# Store the query string
self.string = p_string
"""
1. Tokenize
------------------------------------------------------------------------
"""
# Tokenize the query string, allowing only strings, parentheses,
# forward slashes and commas.
re_all = r'table[(]|\,|[)]|[/]|\w+'
data_tokens = tokenize.regexp(self.string, re_all)
"""
2. Develop a context free grammar
------------------------------------------------------------------------
"""
# Develop a context free grammar
# S = sentence, T = table, H = hierarchy, D = domain
O, T, H, D = cfg.nonterminals('O, T, H, D')
# Specify the grammar
productions = (
# A sentence can be either a table, hierarchy or domain
cfg.Production(O, [D]),
cfg.Production(O, [H]),
cfg.Production(O, [T]),
# A table must be the following sequence:
# "table(", sentence, comma, sentence, comma, sentence, ")"
cfg.Production(T, ['table(', O, ',', O, ',', O, ')']),
# A hierarchy must be the following sequence:
# domain, forward slash, domain
cfg.Production(H, [D, '/', D]),
# domain, forward slash, another operator
cfg.Production(H, [D, '/', O]))
# Add domains to the cfg productions
# A domain is a token that is entirely word chars
re_domain = compile(r'^\w+$')
# Try every token and add if it matches the above regular expression
for tok in data_tokens:
if re_domain.match(tok):
prod = cfg.Production(D, [tok]),
productions = productions + prod
# Make a grammar out of our productions
grammar = cfg.Grammar(O, productions)
rd_parser = parse.RecursiveDescent(grammar)
# Tokens need to be redefined.
# It disappears after first use, and I don't know why.
tokens = tokenize.regexp(self.string, re_all)
toklist = list(tokens)
"""
3. Parse using the context free grammar
------------------------------------------------------------------------
"""
# Store the parsing.
# Only the first one, as the grammar should be completely nonambiguous.
try:
self.parseList = rd_parser.get_parse_list(toklist)[0]
except IndexError:
print "Could not parse query."
return
"""
4. Refine and convert to a Tree representation
------------------------------------------------------------------------
"""
# Set the nltk_lite.parse.tree tree for this query to the global sentence
string = str(self.parseList)
string2 = string.replace(":", "").replace("')'", "").replace(
"table(", "").replace("','", "").replace("'", "").replace("/", "")
self.nltktree = parse.tree.bracket_parse(string2)
# Store the resulting nltk_lite.parse.tree tree
self.parseTree = QuerySentence(self.nltktree)
self.xml = self.parseTree.toXML()
def re2nfa(fsa, re):
tokens = tokenize.regexp(re, pattern=r'.')
tree = _parser.parse(tokens)
if tree is None: raise ValueError('Bad Regexp')
state = re2nfa_build(fsa, fsa.start(), tree)
fsa.set_final([state])