def write_example(self, fd=sys.stdout, params={}):
word = [self.rules[-1][1]]
todo = set(self.rules.keys())
nt = self.nonterminals
def count_nt(k):
return len([X for X in self.rules[k][1:] if X in nt])
while todo:
actions = []
for i, X in enumerate(word):
if X not in nt:
continue
rules = set(k for k, l in self.rule_from_head[X]) & todo
for k in rules:
actions.append((i, k))
good_actions = [a for a in actions if count_nt(a[1]) > 1]
if good_actions:
actions = good_actions
try:
i, k = choice(actions)
except IndexError:
break
word[i:i + 1] = self.rules[k][1:]
if uniform(0, 1) < 0.1 * len(word):
todo.discard(k)
short = self.shortcuts()
res = []
for X in word:
res.extend(repr((Y, )) for Y in short[X])
parser = params.get("parser_name", "")
if parser.endswith(".py"):
parser = basename(parser)[:-3]
else:
parser = "..."
write_block(fd,
0,
"""
#! /usr/bin/env python
# %(example_name)s - illustrate the use of a Wisent-generated parser
# example code autogenerated on %(date)s
# generator: wisent %(version)s, http://seehuhn.de/pages/wisent
""" % params,
first=True)
if 'fname' in params:
fd.write("# source: %(fname)s\n" % params)
fd.write('\n')
fd.write('from sys import stderr\n')
fd.write('\n')
fd.write('from %s import Parser\n' % parser)
write_block(fd, 0, getsource(template.print_tree))
fd.write('\n')
for l in split_it(res, start1="input = [ ", end2=" ]"):
fd.write(l + '\n')
write_block(
fd, 0, """
p = Parser()
try:
tree = p.parse(input)
except p.ParseErrors, e:
for token,expected in e.errors:
if token[0] == p.EOF:
print >>stderr, "unexpected end of file"
continue
found = repr(token[0])
if len(expected) == 1:
msg = "missing %s (found %s)"%(repr(expected[0]), found)
else:
msg1 = "parse error before %s, "%found
l = sorted([ repr(s) for s in expected ])
msg2 = "expected one of "+", ".join(l)
msg = msg1+msg2
print >>stderr, msg
raise SystemExit(1)
""")
fd.write('\n')
fd.write('print_tree(tree, p.terminals)\n')
def write_example(self, fd=sys.stdout, params={}):
word = [ self.rules[-1][1] ]
todo = set(self.rules.keys())
nt = self.nonterminals
def count_nt(k):
return len([X for X in self.rules[k][1:] if X in nt])
while todo:
actions = []
for i,X in enumerate(word):
if X not in nt:
continue
rules = set(k for k,l in self.rule_from_head[X])&todo
for k in rules:
actions.append((i,k))
good_actions = [ a for a in actions if count_nt(a[1])>1 ]
if good_actions:
actions = good_actions
try:
i,k = choice(actions)
except IndexError:
break
word[i:i+1] = self.rules[k][1:]
if uniform(0,1)<0.1*len(word):
todo.discard(k)
short = self.shortcuts()
res = []
for X in word:
res.extend(repr((Y,)) for Y in short[X])
parser = params.get("parser_name", "")
if parser.endswith(".py"):
parser = basename(parser)[:-3]
else:
parser = "..."
write_block(fd, 0, """
#! /usr/bin/env python
# %(example_name)s - illustrate the use of a Wisent-generated parser
# example code autogenerated on %(date)s
# generator: wisent %(version)s, http://seehuhn.de/pages/wisent
"""%params, first=True)
if 'fname' in params:
fd.write("# source: %(fname)s\n"%params)
fd.write('\n')
fd.write('from sys import stderr\n')
fd.write('\n')
fd.write('from %s import Parser\n'%parser)
write_block(fd, 0, getsource(template.print_tree))
fd.write('\n')
for l in split_it(res, start1="input = [ ", end2=" ]"):
fd.write(l+'\n')
write_block(fd, 0, """
p = Parser()
try:
tree = p.parse(input)
except p.ParseErrors, e:
for token,expected in e.errors:
if token[0] == p.EOF:
print >>stderr, "unexpected end of file"
continue
found = repr(token[0])
if len(expected) == 1:
msg = "missing %s (found %s)"%(repr(expected[0]), found)
else:
msg1 = "parse error before %s, "%found
l = sorted([ repr(s) for s in expected ])
msg2 = "expected one of "+", ".join(l)
msg = msg1+msg2
print >>stderr, msg
raise SystemExit(1)
""")
fd.write('\n')
fd.write('print_tree(tree, p.terminals)\n')
def write_parser(self, fd, options={}):
"""Emit Python code implementing the parser.
A complete, stand-alone Python source file implementing the
parser is written to the file-like object `fd`, each line of
the output is prefixed with the string `prefix`.
"""
self.check()
params = options.copy()
from time import strftime
params.setdefault('date', strftime("%Y-%m-%d %H:%M:%S"))
params['version'] = VERSION
write_block(fd,
0,
"""# LR(1) parser, autogenerated on %(date)s
# generator: wisent %(version)s, http://seehuhn.de/pages/wisent
""" % params,
first=True)
if 'fname' in params:
fd.write("# source: %(fname)s\n" % params)
write_block(
fd, 0, """
# All parts of this file which are not taken verbatim from the input grammar
# are covered by the following notice:
#""")
fd.write(getcomments(template))
fd.write('\n')
fd.write('from itertools import chain\n')
write_block(fd, 0, getsource(Unique))
fd.write('\n')
fd.write('class Parser(object):\n\n')
fd.write(' """LR(1) parser class.\n')
if params.get("parser_debugprint", False):
write_block(
fd, 4, """
Instances of this class print additional debug messages and are
not suitable for production use.
""")
fd.write('\n')
self.g.write_terminals(fd, " ")
fd.write('\n')
self.g.write_nonterminals(fd, " ")
fd.write('\n')
self.g.write_productions(fd, " ")
if self.replace_nonterminals:
write_block(
fd, 4, """
In the returned parse trees, nonterminal symbols are
replaced by numbers. You can use the dictionary
`Parser.nonterminals` to map back the numeric codes to the
corresponding symbols.
""")
fd.write(' """\n')
if "parser_comment" in params:
fd.write('\n')
self.write_transition_table(fd)
fd.write('\n')
self.write_parser_states(fd)
write_block(fd, 4, getsource(template.Parser.ParseErrors))
fd.write('\n')
tt = map(repr, sorted(self.g.terminals - set([self.g.EOF])))
for l in split_it(tt,
padding=" ",
start1="terminals = [ ",
end2=" ]"):
fd.write(l + '\n')
nt_tab = self.nt_tab
transparent = params.get("transparent_tokens", set())
transparent &= self.g.nonterminals
if self.replace_nonterminals:
symbols = self.g.nonterminals - set([self.g.start]) - transparent
nonterminals = sorted(symbols)
tt = ["%d: %s" % (nt_tab[X], repr(X)) for X in nonterminals]
for l in split_it(tt,
padding=" ",
start1="nonterminals = { ",
end2=" }"):
fd.write(l + '\n')
if transparent:
tt = [repr(nt_tab[X]) for X in sorted(transparent)]
for l in split_it(tt,
padding=" ",
start1="_transparent = [ ",
end2=" ]"):
fd.write(l + '\n')
fd.write(" EOF = Unique('EOF')\n")
fd.write(" S = Unique('S')\n")
# halting state
fd.write('\n')
fd.write(" _halting_state = %s\n" % self.halting_state)
# reduce actions
rtab = self.rtab
r_items = [
"%s: %s" % (repr(key), repr(rtab[key]))
for key in sorted(self.rtab)
]
fd.write(" _reduce = {\n")
for l in split_it(r_items, padding=" "):
fd.write(l + '\n')
fd.write(" }\n")
# goto table
gtab = self.gtab
g_items = [
"%s: %s" % (repr(key), repr(gtab[key]))
for key in sorted(self.gtab)
]
fd.write(" _goto = {\n")
for l in split_it(g_items, padding=" "):
fd.write(l + '\n')
fd.write(" }\n")
# shift table
stab = self.stab
s_items = [
"%s: %s" % (repr(key), repr(stab[key]))
for key in sorted(self.stab)
]
fd.write(" _shift = {\n")
for l in split_it(s_items, padding=" "):
fd.write(l + '\n')
fd.write(" }\n")
write_block(fd, 4, getsource(template.Parser.__init__), params)
write_block(fd, 4, getsource(template.Parser.leaves), params)
write_block(fd, 4, getsource(template.Parser._parse), params)
write_block(fd, 4, getsource(template.Parser._try_parse), params)
write_block(fd, 4, getsource(template.Parser.parse), params)
def write_parser(self, fd, options={}):
"""Emit Python code implementing the parser.
A complete, stand-alone Python source file implementing the
parser is written to the file-like object `fd`, each line of
the output is prefixed with the string `prefix`.
"""
self.check()
params = options.copy()
from time import strftime
params.setdefault('date', strftime("%Y-%m-%d %H:%M:%S"))
params['version'] = VERSION
write_block(fd, 0, """# LR(1) parser, autogenerated on %(date)s
# generator: wisent %(version)s, http://seehuhn.de/pages/wisent
"""%params, first=True)
if 'fname' in params:
fd.write("# source: %(fname)s\n"%params)
write_block(fd, 0, """
# All parts of this file which are not taken verbatim from the input grammar
# are covered by the following notice:
#""")
fd.write(getcomments(template))
fd.write('\n')
fd.write('from itertools import chain\n')
write_block(fd, 0, getsource(Unique))
fd.write('\n')
fd.write('class Parser(object):\n\n')
fd.write(' """LR(1) parser class.\n')
if params.get("parser_debugprint", False):
write_block(fd, 4, """
Instances of this class print additional debug messages and are
not suitable for production use.
""")
fd.write('\n')
self.g.write_terminals(fd, " ")
fd.write('\n')
self.g.write_nonterminals(fd, " ")
fd.write('\n')
self.g.write_productions(fd, " ")
if self.replace_nonterminals:
write_block(fd, 4, """
In the returned parse trees, nonterminal symbols are
replaced by numbers. You can use the dictionary
`Parser.nonterminals` to map back the numeric codes to the
corresponding symbols.
""")
fd.write(' """\n')
if "parser_comment" in params:
fd.write('\n')
self.write_transition_table(fd)
fd.write('\n')
self.write_parser_states(fd)
write_block(fd, 4, getsource(template.Parser.ParseErrors))
fd.write('\n')
tt = map(repr, sorted(self.g.terminals-set([self.g.EOF])))
for l in split_it(tt, padding=" ", start1="terminals = [ ",
end2=" ]"):
fd.write(l+'\n')
nt_tab = self.nt_tab
transparent = params.get("transparent_tokens", set())
transparent &= self.g.nonterminals
if self.replace_nonterminals:
symbols = self.g.nonterminals-set([self.g.start])-transparent
nonterminals = sorted(symbols)
tt = [ "%d: %s"%(nt_tab[X],repr(X)) for X in nonterminals ]
for l in split_it(tt, padding=" ",
start1="nonterminals = { ", end2=" }"):
fd.write(l+'\n')
if transparent:
tt = [ repr(nt_tab[X]) for X in sorted(transparent) ]
for l in split_it(tt, padding=" ",
start1="_transparent = [ ", end2=" ]"):
fd.write(l+'\n')
fd.write(" EOF = Unique('EOF')\n")
fd.write(" S = Unique('S')\n")
# halting state
fd.write('\n')
fd.write(" _halting_state = %s\n"%self.halting_state)
# reduce actions
rtab = self.rtab
r_items = [ "%s: %s"%(repr(key),repr(rtab[key]))
for key in sorted(self.rtab) ]
fd.write(" _reduce = {\n")
for l in split_it(r_items, padding=" "):
fd.write(l+'\n')
fd.write(" }\n")
# goto table
gtab = self.gtab
g_items = [ "%s: %s"%(repr(key),repr(gtab[key]))
for key in sorted(self.gtab) ]
fd.write(" _goto = {\n")
for l in split_it(g_items, padding=" "):
fd.write(l+'\n')
fd.write(" }\n")
# shift table
stab = self.stab
s_items = [ "%s: %s"%(repr(key),repr(stab[key]))
for key in sorted(self.stab) ]
fd.write(" _shift = {\n")
for l in split_it(s_items, padding=" "):
fd.write(l+'\n')
fd.write(" }\n")
write_block(fd, 4, getsource(template.Parser.__init__), params)
write_block(fd, 4, getsource(template.Parser.leaves), params)
write_block(fd, 4, getsource(template.Parser._parse), params)
write_block(fd, 4, getsource(template.Parser._try_parse), params)
write_block(fd, 4, getsource(template.Parser.parse), params)