def mine_grammar(self):
grammar = extend_grammar(self.QUERY_GRAMMAR)
grammar["<action>"] = [self.action]
query = ""
for field in self.fields:
field_symbol = new_symbol(grammar, "<" + field + ">")
field_type = self.fields[field]
if query != "":
query += "&"
query += field_symbol
if isinstance(field_type, str):
field_type_symbol = "<" + field_type + ">"
grammar[field_symbol] = [field + "=" + field_type_symbol]
if field_type_symbol not in grammar:
# Unknown type
grammar[field_type_symbol] = ["<text>"]
else:
# List of values
value_symbol = new_symbol(grammar, "<" + field + "-value>")
grammar[field_symbol] = [field + "=" + value_symbol]
grammar[value_symbol] = field_type
grammar["<query>"] = [query]
# Remove unused parts
for nonterminal in unreachable_nonterminals(grammar):
del grammar[nonterminal]
assert is_valid_grammar(grammar)
return grammar
def mine_state_grammar(self, grammar={}, state_symbol=None):
grammar = extend_grammar(self.GUI_GRAMMAR, grammar)
if state_symbol is None:
state_symbol = self.new_state_symbol(grammar)
grammar[state_symbol] = []
alternatives = []
form = ""
submit = None
for action in self.mine_state_actions():
if action.startswith("submit"):
submit = action
elif action.startswith("click"):
link_target = self.new_state_symbol(grammar)
grammar[link_target] = [self.UNEXPLORED_STATE]
alternatives.append(action + '\n' + link_target)
elif action.startswith("ignore"):
pass
else: # fill(), check() actions
if len(form) > 0:
form += '\n'
form += action
if submit is not None:
if len(form) > 0:
form += '\n'
form += submit
if len(form) > 0:
form_target = self.new_state_symbol(grammar)
grammar[form_target] = [self.UNEXPLORED_STATE]
alternatives.append(form + '\n' + form_target)
alternatives += [self.FINAL_STATE]
grammar[state_symbol] = alternatives
# Remove unused parts
for nonterminal in unreachable_nonterminals(grammar):
del grammar[nonterminal]
assert is_valid_grammar(grammar)
return grammar
def duplicate_context(grammar, symbol, expansion=None, depth=float('inf')):
"""Duplicate an expansion within a grammar.
In the given grammar, take the given expansion of the given symbol
(if expansion is omitted: all symbols), and replace it with a
new expansion referring to a duplicate of all originally referenced rules.
If depth is given, limit duplication to `depth` references (default: unlimited)
"""
orig_grammar = extend_grammar(grammar)
_duplicate_context(grammar, orig_grammar, symbol,
expansion, depth, seen={})
# After duplication, we may have unreachable rules; delete them
for nonterminal in unreachable_nonterminals(grammar):
del grammar[nonterminal]
def make_grammar(num_symbols=3, num_alts=3):
terminals = list(string.ascii_lowercase)
grammar = {}
name = None
for _ in range(num_symbols):
nonterminals = [k[1:-1] for k in grammar.keys()]
name, expansions = \
make_rule(nonterminals, terminals, num_alts)
grammar[name] = expansions
grammar[START_SYMBOL] = [name]
# Remove unused parts
for nonterminal in unreachable_nonterminals(grammar):
del grammar[nonterminal]
assert is_valid_grammar(grammar)
return grammar
def replace_symbol(grammar, old_symbol, new_symbol):
"""Return a grammar in which all occurrences of `old_symbol` are replaced by `new_symbol`"""
new_grammar = {}
for symbol in grammar:
new_expansions = []
for expansion in grammar[symbol]:
new_expansion_string = exp_string(expansion).replace(old_symbol, new_symbol)
if len(exp_opts(expansion)) > 0:
new_expansion = (new_expansion_string, exp_opts(expansion))
else:
new_expansion = new_expansion_string
new_expansions.append(new_expansion)
new_grammar[symbol] = new_expansions
# Remove unused parts
for nonterminal in unreachable_nonterminals(new_grammar):
del new_grammar[nonterminal]
return new_grammar
def set_arguments(self, args):
self._ebnf_grammar["<arguments>"] = [" " + args]
# Delete rules for previous arguments
for nonterminal in unreachable_nonterminals(self._ebnf_grammar):
del self._ebnf_grammar[nonterminal]
