def _search(self, string, tokstream):
self.begin = 0
self.end = 0
n = len(tokstream)
tracer = TokenTracer(self.langlet, self.symbol)
initial = tracer.selectables()
i = 0
while i<n:
tok = tokstream[i]
if tok[0] in initial:
selection = []
K = None
for j,T in enumerate(tokstream[i:]):
if not self.accept_token(T):
continue
try:
selection = tracer.select(T[0])
except NonSelectableError:
if K is not None:
stream = tokstream[i:i+K+1]
if self.condition(stream):
m = CMatchObject(string)
first = stream[0]
last = stream[-1]
m.begin = get_index(string, first[2])+first[-1][0]+1
m.end = get_index(string, last[2])+last[-1][1]+1
m.matched = string[m.begin: m.end]
m.tokstream = TokenStream(stream)
m.tokpos = i
return m
break
if FIN in selection:
K = j
tracer = TokenTracer(self.langlet, self.symbol)
i+=1
def _check_gene(self, gene):
tr = TokenTracer(self.langlet)
try:
res, idx = tr.check(gene)
except (KeyError, TypeError):
print gene
raise
return res
def _lookahead(self, tokstream, S, sym):
tokstream = tokstream.clone()
tracer_data = {}
tts = []
for s in S:
if is_symbol(s):
tt = TokenTracer(self.langlet, s)
else:
# jump to state with nid = s within the current NFA
states = self._get_states(s, sym)
if not states:
return -1
tt = TokenTracer(self.langlet,
sym,
jump_to_state=states,
without_expansion=False)
tts.append(tt)
tracer_data[tt] = (s, -1)
n = len(tokstream)
p = tokstream.position
m = -1
while p < n:
nid = tokstream[p][0]
if nid == INTRON_NID:
p += 1
continue
removable = []
for tt in tts:
selection = tt.selectables()
if FIN in selection:
s, _ = tracer_data[tt]
tracer_data[tt] = (s, p)
m = p
if nid not in selection:
removable.append(tt)
else:
tt.select(nid)
for tt in removable:
tts.remove(tt)
if len(tts) == 1:
s, q = tracer_data[tts[0]]
if q >= 0:
return (tracer_data[tts[0]][0], p, None)
elif len(tts) == 0:
if p > m:
ttcancel = removable[-1]
s, _ = tracer_data[ttcancel]
self._last_scan_point = (s, p, tokstream[p],
ttcancel.selectables())
if m >= 0:
for tt, (s, i) in tracer_data.items():
if i == m:
return (s, p, None)
selectable = set()
for tt in removable:
selectable.update(tt.selectables())
return (-1, p, selectable)
p += 1
return (-1, p, set())
def gen_token_string(self, nid):
tracer = TokenTracer(self.langlet, nid, "lex")
selection = list(tracer.selectables())
S = []
while True:
n = len(selection)
if selection == [FIN]:
return ''.join(S)
if len(S) > 20:
return self.gen_token_string(nid)
while True:
m = random.randrange(0, n)
t = selection[m]
if t is FIN:
continue
try:
chars = list(self.lexer_terminal[t])
except KeyError:
return ''
if not chars:
other_chars = reduce(lambda S, T: S.union(T), [
self.lexer_terminal.get(r, set())
for r in selection if r != t
], set())
while True:
c = random_printable()
if c == '\\':
continue
if c not in other_chars:
break
S.append(c)
else:
c = chars[random.randrange(0, len(chars))]
S.append(c)
selection = list(tracer.select(t))
break
if len(S) >= self.stdlen:
if FIN in selection:
if S[0] in ('"', "'"):
if len(S) >= 4:
return ''.join(S)
if S[0] in string.digits:
if len(S) >= 4:
return ''.join(S)
if random.randrange(0, 2) == 0:
return ''.join(S)
def delete(self, g):
visited = set()
while True:
n = len(g) - 1
if len(visited)>=n:
return g
gene = g[:]
k = random.randrange(0, n)
visited.add(k)
T = gene[k+1][0]
del gene[k+1]
n-=1
R = self.get_right_par(T+SYMBOL_OFFSET) # TODO: consider 'extended braces'
loc = []
if R:
R-=SYMBOL_OFFSET
for i, tok in enumerate(gene[k+1:]):
if tok[0] == R:
loc.append(i+k+1)
else:
L = self.get_left_par(T+SYMBOL_OFFSET)
if L:
L-=SYMBOL_OFFSET
for i, tok in enumerate(gene[:k]):
if tok[0] == L:
loc.append(i)
if loc:
while loc:
m = loc[random.randrange(0, len(loc))]
backup = gene[m]
del gene[m]
tr = TokenTracer(self.langlet)
res, idx = tr.check(gene)
if res == True:
return gene
else:
loc.remove(m)
gene.insert(m, backup)
continue
else:
if self._check_gene(gene):
return gene
else:
continue
def gen_token_string(self, nid):
tracer = TokenTracer(self.langlet, nid, "lex")
selection = list(tracer.selectables())
S = []
while True:
n = len(selection)
if selection == [FIN]:
return ''.join(S)
if len(S)>20:
return self.gen_token_string(nid)
while True:
m = random.randrange(0, n)
t = selection[m]
if t is FIN:
continue
try:
chars = list(self.lexer_terminal[t])
except KeyError:
return ''
if not chars:
other_chars = reduce(lambda S, T: S.union(T), [self.lexer_terminal.get(r, set()) for r in selection if r!=t], set())
while True:
c = random_printable()
if c == '\\':
continue
if c not in other_chars:
break
S.append(c)
else:
c = chars[random.randrange(0, len(chars))]
S.append(c)
selection = list(tracer.select(t))
break
if len(S) >= self.stdlen:
if FIN in selection:
if S[0] in ('"', "'"):
if len(S)>=4:
return ''.join(S)
if S[0] in string.digits:
if len(S)>=4:
return ''.join(S)
if random.randrange(0,2) == 0:
return ''.join(S)
def insert(self, g):
trials = set()
while True:
gene = g[:]
n = len(gene) - 1
k, T, tracer = self._seek_random_item(gene, trials)
if T is None:
continue
value = self.gen_token_string(T+SYMBOL_OFFSET)
gene.insert(k+1, [T, value])
n+=1
R = self.get_right_par(T+SYMBOL_OFFSET) # TODO: consider 'extended braces'
if R:
R-=SYMBOL_OFFSET
i = 1
loc = []
while k+i<n:
try:
selection = tracer.select(gene[k+i][0])
except NonSelectableError:
break
if R in selection:
loc.append(k+i)
i+=1
if loc:
value = self.gen_token_string(R+SYMBOL_OFFSET)
while loc:
m = loc[random.randrange(0, len(loc))]
gene.insert(m+1, [R, value])
tr = TokenTracer(self.langlet)
res, idx = tr.check(gene)
if res == True:
return gene
else:
loc.remove(m)
continue
else:
continue
else:
if self._check_gene(gene):
return gene
else:
continue
def _repair(self, tokenstream):
'''
Maybe the tokenstream needs some repair? Insert constant token, when needed.
'''
n = len(tokenstream)
tt = TokenTracer(self.langlet, start=self.start_symbol)
selectables = tt.selectables()
repaired = []
i = 0
while i < n:
tok = tokenstream[i]
# print tok
if tok[0] in selectables:
repaired.append(tok)
selectables = tt.select(tok[0])
else:
# find a const token T which can be inserted between token[i] and token[i+1]
S = []
for s in selectables:
if s in self.constants:
_tt = tt.clone()
_selectables = _tt.select(s)
if i == n - 1:
if FIN in _selectables:
repaired.append([s, self.constants[s]])
break
else:
T = tokenstream[i + 1]
if T[0] in _selectables:
S.append(s)
selectables = _selectables
else:
if S == []:
if tok[1].strip() == "": # forgotten a linebreak?
i += 1
continue
# TODO: replace this by an expressive error message
self.compute_syntax_error(tokenstream, i)
elif len(S) == 1:
selectables = _selectables
repaired.append([s, self.constants[s]])
i += 1
return repaired
def _repair(self, tokenstream):
'''
Maybe the tokenstream needs some repair? Insert constant token, when needed.
'''
n = len(tokenstream)
tt = TokenTracer(self.langlet, start = self.start_symbol)
selectables = tt.selectables()
repaired = []
i = 0
while i<n:
tok = tokenstream[i]
# print tok
if tok[0] in selectables:
repaired.append(tok)
selectables = tt.select(tok[0])
else:
# find a const token T which can be inserted between token[i] and token[i+1]
S = []
for s in selectables:
if s in self.constants:
_tt = tt.clone()
_selectables = _tt.select(s)
if i == n-1:
if FIN in _selectables:
repaired.append([s, self.constants[s]])
break
else:
T = tokenstream[i+1]
if T[0] in _selectables:
S.append(s)
selectables = _selectables
else:
if S == []:
if tok[1].strip() == "": # forgotten a linebreak?
i+=1
continue
# TODO: replace this by an expressive error message
self.compute_syntax_error(tokenstream, i)
elif len(S) == 1:
selectables = _selectables
repaired.append([s, self.constants[s]])
i+=1
return repaired
def _seek_random_item(self, gene, trials):
n = len(gene) - 1
if len(trials) == n:
trials.clear()
while True:
k = random.randrange(-1, n)
if k not in trials:
break
trials.add(k)
tracer = TokenTracer(self.langlet)
selection = []
for i, tok in enumerate(gene):
if i<=k:
tracer.select(tok[0])
else:
break
selection = list(tracer.selectables())
m = random.randrange(0, len(selection))
T = selection[m]
return k, T, tracer
def run(self, start=None, maxlen=3, exclude = ()):
ttracer = TokenTracer(self.langlet, start = start)
L = []
def create_trace(ttracer, selection, L, n):
R = []
if n == 0:
if None in selection:
return [L]
else:
return []
for s in selection:
if s is None:
R.append(L)
elif s not in exclude:
subtracer = ttracer.clone()
subselect = subtracer.select(s)
R+=create_trace(subtracer, subselect, L+[s], n-1)
return R
R = []
L = []
traces = create_trace(ttracer, ttracer.selectables(), L, maxlen)
return traces
def _lookahead(self, tokstream, S, sym):
tokstream = tokstream.clone()
tracer_data = {}
tts = []
for s in S:
if is_symbol(s):
tt = TokenTracer(self.langlet, s)
else:
# jump to state with nid = s within the current NFA
states = self._get_states(s, sym)
if not states:
return -1
tt = TokenTracer(self.langlet, sym, jump_to_state = states, without_expansion = False)
tts.append(tt)
tracer_data[tt] = (s, -1)
n = len(tokstream)
p = tokstream.position
m = -1
while p<n:
nid = tokstream[p][0]
if nid == INTRON_NID:
p+=1
continue
removable = []
for tt in tts:
selection = tt.selectables()
if FIN in selection:
s, _ = tracer_data[tt]
tracer_data[tt] = (s, p)
m = p
if nid not in selection:
removable.append(tt)
else:
tt.select(nid)
for tt in removable:
tts.remove(tt)
if len(tts) == 1:
s, q = tracer_data[tts[0]]
if q>=0:
return (tracer_data[tts[0]][0], p, None)
elif len(tts) == 0:
if p > m:
ttcancel = removable[-1]
s, _ = tracer_data[ttcancel]
self._last_scan_point = (s, p, tokstream[p], ttcancel.selectables())
if m >= 0:
for tt, (s, i) in tracer_data.items():
if i == m:
return (s, p, None)
selectable = set()
for tt in removable:
selectable.update(tt.selectables())
return (-1, p, selectable)
p+=1
return (-1, p, set())
def subst(self, g):
trials = set()
n = len(g) - 1
while True:
gene = g[:]
k = random.randrange(-1, n)
tracer = TokenTracer(self.langlet)
for i, tok in enumerate(gene):
if i<=k:
tracer.select(tok[0])
else:
break
selection = list(tracer.selectables())
while k+1<n:
if len(selection) == 1:
k+=1
selection = list(tracer.select(gene[k][0]))
continue
while selection:
m = random.randrange(0, len(selection))
T = selection[m]
selection.remove(T)
if T is None:
continue
value = self.gen_token_string(T+SYMBOL_OFFSET)
backup = gene[k+1]
if backup[1] == value:
continue
gene[k+1] = [T, value]
tr = TokenTracer(self.langlet)
try:
res, idx = tr.check(gene)
except (KeyError, TypeError):
print gene
raise
if res == True:
return gene
else:
gene[k+1] = backup
k+=1
def _search(self, string, tokstream):
self.begin = 0
self.end = 0
n = len(tokstream)
tracer = TokenTracer(self.langlet, self.symbol)
initial = tracer.selectables()
i = 0
while i < n:
tok = tokstream[i]
if tok[0] in initial:
selection = []
K = None
for j, T in enumerate(tokstream[i:]):
if not self.accept_token(T):
continue
try:
selection = tracer.select(T[0])
except NonSelectableError:
if K is not None:
stream = tokstream[i:i + K + 1]
if self.condition(stream):
m = CMatchObject(string)
first = stream[0]
last = stream[-1]
m.begin = get_index(
string, first[2]) + first[-1][0] + 1
m.end = get_index(string,
last[2]) + last[-1][1] + 1
m.matched = string[m.begin:m.end]
m.tokstream = TokenStream(stream)
m.tokpos = i
return m
break
if FIN in selection:
K = j
tracer = TokenTracer(self.langlet, self.symbol)
i += 1
nfa_E = [
"E: a '+' E | a '*' E | 'a'", (E, 0, E), {
(E, 0, E): [(a, 1, E), (a, 2, E), (a, 3, E)],
(a, 1, E): [(PLUS, 4, E)],
(a, 2, E): [(MUL, 5, E)],
(PLUS, 4, E): [(E, 6, E)],
(MUL, 5, E): [(E, 7, E)],
(a, 3, E): [(FIN, FEX, E)],
(E, 6, E): [(FIN, FEX, E)],
(E, 7, E): [(FIN, FEX, E)]
}
]
nfa_E2 = [
"E: a E", (E, 0, E), {
(E, 0, E): [(a, 1, E)],
(a, 1, E): [(E, 2, E)],
(E, 2, E): [(FIN, FEX, E)]
}
]
langlet.parse_nfa.nfas[E] = nfa_E2
tt = TokenTracer(langlet)
tt.selectables()
tt.select(1)
tt.select(1)
tt.select(1)
tt.select(1)
tt.select(1)
langlet.parse_nfa.start_symbols = (E,)
nfa_E = ["E: a '+' E | a '*' E | 'a'",
(E,0,E),
{(E,0,E):[(a,1,E),(a,2,E),(a,3,E)],
(a,1,E):[(PLUS,4,E)],
(a,2,E):[(MUL,5,E)],
(PLUS,4,E):[(E,6,E)],
(MUL,5,E):[(E,7,E)],
(a,3,E):[(FIN, FEX, E)],
(E,6,E):[(FIN, FEX,E)],
(E,7,E):[(FIN, FEX,E)]}]
nfa_E2 = ["E: a E",
(E,0,E),
{(E,0,E):[(a,1,E)],
(a,1,E):[(E,2,E)],
(E,2,E):[(FIN, FEX,E)]}]
langlet.parse_nfa.nfas[E] = nfa_E2
tt = TokenTracer(langlet)
tt.selectables()
tt.select(1)
tt.select(1)
tt.select(1)
tt.select(1)
tt.select(1)
def random_rule(stoplen):
# some rules to constrain 'interesting' cases
#
# 1. Avoid double parens (( ... )) or double square braces [[ ... ]]
# 2. Avoid use of STRING
# 3. Avoid sequences of NAME longer than 2 i.e. NAME NAME NAME
trace = []
ttracer = TokenTracer(ls_grammar, start = ls_grammar.symbol.rhs)
STRING = ls_grammar.token.STRING
NAME = ls_grammar.token.NAME
LPAR = ls_grammar.token.LPAR
RPAR = ls_grammar.token.RPAR
LSQB = ls_grammar.token.LSQB
RSQB = ls_grammar.token.RSQB
selection = list(ttracer.selectables())
while True:
# print len(trace), selection
if len(trace)>stoplen:
if None in selection:
return trace
elif RSQB in selection:
trace.append(RSQB)
selection = ttracer.select(RSQB)
continue
elif RPAR in selection:
trace.append(RPAR)
selection = ttracer.select(RPAR)
continue
while selection:
k = random.randrange(len(selection))
item = selection[k]
selection.remove(item)
if item is None:
continue
if item == STRING:
continue
elif item in (NAME, LPAR, LSQB):
if len(trace)>=2:
if trace[-1] == trace[-2] == item:
continue
if item in (LPAR, LSQB):
if trace[-2] in (LPAR, LSQB) and trace[-1] in (LPAR, LSQB):
continue
elif item in (RSQB, RPAR):
if trace and trace[-1] == item:
if item == RSQB:
LEFT = LSQB
else:
LEFT = LPAR
RIGHT = item
m = len(trace)-2
double = False
level = -2
while m:
if trace[m] == RIGHT:
level-=1
elif trace[m] == LEFT:
level+=1
if level == 0:
if trace[m+1] == LEFT:
double = True
break
m-=1
if double:
continue
trace.append(item)
selection = list(ttracer.select(item))
break
S.append(c)
else:
c = chars[random.randrange(0, len(chars))]
S.append(c)
selection = list(tracer.select(t))
break
if len(S) >= self.stdlen:
if FIN in selection:
if S[0] in ('"', "'"):
if len(S) >= 4:
return ''.join(S)
if S[0] in string.digits:
if len(S) >= 4:
return ''.join(S)
if random.randrange(0, 2) == 0:
return ''.join(S)
if __name__ == '__main__':
import langscape
from langscape.trail.tokentracer import TokenTracer
python = langscape.load_langlet("python")
tracer = TokenTracer(python, python.lex_symbol.Single3, "lex")
tokgen = TokenGenerator(python)
for i in range(100):
s = tokgen.gen_token_string(python.lex_symbol.NAME)
print s
#print "NUM", "%-8s %s"%(s, eval(s))
