summaryrefslogtreecommitdiffstats
path: root/Parser
diff options
context:
space:
mode:
authorTim Peters <tim.peters@gmail.com>2005-12-25 23:18:31 (GMT)
committerTim Peters <tim.peters@gmail.com>2005-12-25 23:18:31 (GMT)
commit536cf99536bce562cfcb44a856fac1c84b9de4c3 (patch)
tree80cf0f425cfc703b228aad716ed66cd4a5080c03 /Parser
parent83a8c393b06d24b3c6b252b7614c34110c369c43 (diff)
downloadcpython-536cf99536bce562cfcb44a856fac1c84b9de4c3.zip
cpython-536cf99536bce562cfcb44a856fac1c84b9de4c3.tar.gz
cpython-536cf99536bce562cfcb44a856fac1c84b9de4c3.tar.bz2
Whitespace normalization.
Diffstat (limited to 'Parser')
-rw-r--r--Parser/asdl.py8
-rwxr-xr-xParser/asdl_c.py100
-rw-r--r--Parser/spark.py1520
3 files changed, 814 insertions, 814 deletions
diff --git a/Parser/asdl.py b/Parser/asdl.py
index 0db4e3b..5b856dd 100644
--- a/Parser/asdl.py
+++ b/Parser/asdl.py
@@ -142,7 +142,7 @@ class ASDLParser(spark.GenericParser, object):
def p_product(self, (_0, fields, _1)):
" product ::= ( fields ) "
# XXX can't I just construct things in the right order?
- fields.reverse()
+ fields.reverse()
return Product(fields)
def p_sum_0(self, (constructor,)):
@@ -164,7 +164,7 @@ class ASDLParser(spark.GenericParser, object):
def p_constructor_1(self, (id, _0, fields, _1)):
" constructor ::= Id ( fields ) "
# XXX can't I just construct things in the right order?
- fields.reverse()
+ fields.reverse()
return Constructor(id, fields)
def p_fields_0(self, (field,)):
@@ -355,7 +355,7 @@ def check(mod):
v.errors += 1
uses = ", ".join(v.types[t])
print "Undefined type %s, used in %s" % (t, uses)
-
+
return not v.errors
def parse(file):
@@ -380,7 +380,7 @@ if __name__ == "__main__":
else:
testdir = "tests"
files = glob.glob(testdir + "/*.asdl")
-
+
for file in files:
print file
mod = parse(file)
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index b1fc77d..766be67 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -439,7 +439,7 @@ class FreeVisitor(PickleVisitor):
self.emit("", 0)
self.emit("free(o);", 1)
self.func_end()
-
+
def visitConstructor(self, cons, enum, name):
self.emit("case %s_kind:" % cons.name, 1)
for f in cons.fields:
@@ -487,76 +487,76 @@ class FreeVisitor(PickleVisitor):
else:
ctype = get_c_type(field.type)
self.emit("free_%s((%s)%s);" % (field.type, ctype, value), depth)
-
+
class MarshalUtilVisitor(StaticVisitor):
CODE = '''
#define CHECKSIZE(BUF, OFF, MIN) { \\
- int need = *(OFF) + MIN; \\
- if (need >= PyString_GET_SIZE(*(BUF))) { \\
- int newsize = PyString_GET_SIZE(*(BUF)) * 2; \\
- if (newsize < need) \\
- newsize = need; \\
- if (_PyString_Resize((BUF), newsize) < 0) \\
- return 0; \\
- } \\
-}
-
-static int
+ int need = *(OFF) + MIN; \\
+ if (need >= PyString_GET_SIZE(*(BUF))) { \\
+ int newsize = PyString_GET_SIZE(*(BUF)) * 2; \\
+ if (newsize < need) \\
+ newsize = need; \\
+ if (_PyString_Resize((BUF), newsize) < 0) \\
+ return 0; \\
+ } \\
+}
+
+static int
marshal_write_int(PyObject **buf, int *offset, int x)
{
- char *s;
-
- CHECKSIZE(buf, offset, 4)
- s = PyString_AS_STRING(*buf) + (*offset);
- s[0] = (x & 0xff);
- s[1] = (x >> 8) & 0xff;
- s[2] = (x >> 16) & 0xff;
- s[3] = (x >> 24) & 0xff;
- *offset += 4;
- return 1;
+ char *s;
+
+ CHECKSIZE(buf, offset, 4)
+ s = PyString_AS_STRING(*buf) + (*offset);
+ s[0] = (x & 0xff);
+ s[1] = (x >> 8) & 0xff;
+ s[2] = (x >> 16) & 0xff;
+ s[3] = (x >> 24) & 0xff;
+ *offset += 4;
+ return 1;
}
-static int
+static int
marshal_write_bool(PyObject **buf, int *offset, bool b)
{
- if (b)
- marshal_write_int(buf, offset, 1);
- else
- marshal_write_int(buf, offset, 0);
- return 1;
+ if (b)
+ marshal_write_int(buf, offset, 1);
+ else
+ marshal_write_int(buf, offset, 0);
+ return 1;
}
-static int
+static int
marshal_write_identifier(PyObject **buf, int *offset, identifier id)
{
- int l = PyString_GET_SIZE(id);
- marshal_write_int(buf, offset, l);
- CHECKSIZE(buf, offset, l);
- memcpy(PyString_AS_STRING(*buf) + *offset,
- PyString_AS_STRING(id), l);
- *offset += l;
- return 1;
+ int l = PyString_GET_SIZE(id);
+ marshal_write_int(buf, offset, l);
+ CHECKSIZE(buf, offset, l);
+ memcpy(PyString_AS_STRING(*buf) + *offset,
+ PyString_AS_STRING(id), l);
+ *offset += l;
+ return 1;
}
-static int
+static int
marshal_write_string(PyObject **buf, int *offset, string s)
{
- int len = PyString_GET_SIZE(s);
- marshal_write_int(buf, offset, len);
- CHECKSIZE(buf, offset, len);
- memcpy(PyString_AS_STRING(*buf) + *offset,
- PyString_AS_STRING(s), len);
- *offset += len;
- return 1;
+ int len = PyString_GET_SIZE(s);
+ marshal_write_int(buf, offset, len);
+ CHECKSIZE(buf, offset, len);
+ memcpy(PyString_AS_STRING(*buf) + *offset,
+ PyString_AS_STRING(s), len);
+ *offset += len;
+ return 1;
}
-static int
+static int
marshal_write_object(PyObject **buf, int *offset, object s)
{
- /* XXX */
- return 0;
+ /* XXX */
+ return 0;
}
'''
@@ -575,7 +575,7 @@ class MarshalFunctionVisitor(PickleVisitor):
self.emit("return 1;", 1)
self.emit("}", 0)
self.emit("", 0)
-
+
def visitSum(self, sum, name):
self.func_begin(name, has_sequence(sum.types, False))
simple = is_simple(sum)
@@ -594,7 +594,7 @@ class MarshalFunctionVisitor(PickleVisitor):
for field in prod.fields:
self.visitField(field, name, 1, 1)
self.func_end()
-
+
def visitConstructor(self, cons, enum, name, simple):
if simple:
self.emit("case %s:" % cons.name, 1)
diff --git a/Parser/spark.py b/Parser/spark.py
index 00d9733..2c18623 100644
--- a/Parser/spark.py
+++ b/Parser/spark.py
@@ -1,5 +1,5 @@
# Copyright (c) 1998-2002 John Aycock
-#
+#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
@@ -7,10 +7,10 @@
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
-#
+#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
-#
+#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
@@ -26,651 +26,651 @@ import sys
import string
def _namelist(instance):
- namelist, namedict, classlist = [], {}, [instance.__class__]
- for c in classlist:
- for b in c.__bases__:
- classlist.append(b)
- for name in c.__dict__.keys():
- if not namedict.has_key(name):
- namelist.append(name)
- namedict[name] = 1
- return namelist
+ namelist, namedict, classlist = [], {}, [instance.__class__]
+ for c in classlist:
+ for b in c.__bases__:
+ classlist.append(b)
+ for name in c.__dict__.keys():
+ if not namedict.has_key(name):
+ namelist.append(name)
+ namedict[name] = 1
+ return namelist
class GenericScanner:
- def __init__(self, flags=0):
- pattern = self.reflect()
- self.re = re.compile(pattern, re.VERBOSE|flags)
-
- self.index2func = {}
- for name, number in self.re.groupindex.items():
- self.index2func[number-1] = getattr(self, 't_' + name)
-
- def makeRE(self, name):
- doc = getattr(self, name).__doc__
- rv = '(?P<%s>%s)' % (name[2:], doc)
- return rv
-
- def reflect(self):
- rv = []
- for name in _namelist(self):
- if name[:2] == 't_' and name != 't_default':
- rv.append(self.makeRE(name))
-
- rv.append(self.makeRE('t_default'))
- return string.join(rv, '|')
-
- def error(self, s, pos):
- print "Lexical error at position %s" % pos
- raise SystemExit
-
- def tokenize(self, s):
- pos = 0
- n = len(s)
- while pos < n:
- m = self.re.match(s, pos)
- if m is None:
- self.error(s, pos)
-
- groups = m.groups()
- for i in range(len(groups)):
- if groups[i] and self.index2func.has_key(i):
- self.index2func[i](groups[i])
- pos = m.end()
-
- def t_default(self, s):
- r'( . | \n )+'
- print "Specification error: unmatched input"
- raise SystemExit
+ def __init__(self, flags=0):
+ pattern = self.reflect()
+ self.re = re.compile(pattern, re.VERBOSE|flags)
+
+ self.index2func = {}
+ for name, number in self.re.groupindex.items():
+ self.index2func[number-1] = getattr(self, 't_' + name)
+
+ def makeRE(self, name):
+ doc = getattr(self, name).__doc__
+ rv = '(?P<%s>%s)' % (name[2:], doc)
+ return rv
+
+ def reflect(self):
+ rv = []
+ for name in _namelist(self):
+ if name[:2] == 't_' and name != 't_default':
+ rv.append(self.makeRE(name))
+
+ rv.append(self.makeRE('t_default'))
+ return string.join(rv, '|')
+
+ def error(self, s, pos):
+ print "Lexical error at position %s" % pos
+ raise SystemExit
+
+ def tokenize(self, s):
+ pos = 0
+ n = len(s)
+ while pos < n:
+ m = self.re.match(s, pos)
+ if m is None:
+ self.error(s, pos)
+
+ groups = m.groups()
+ for i in range(len(groups)):
+ if groups[i] and self.index2func.has_key(i):
+ self.index2func[i](groups[i])
+ pos = m.end()
+
+ def t_default(self, s):
+ r'( . | \n )+'
+ print "Specification error: unmatched input"
+ raise SystemExit
#
# Extracted from GenericParser and made global so that [un]picking works.
#
class _State:
- def __init__(self, stateno, items):
- self.T, self.complete, self.items = [], [], items
- self.stateno = stateno
+ def __init__(self, stateno, items):
+ self.T, self.complete, self.items = [], [], items
+ self.stateno = stateno
class GenericParser:
- #
- # An Earley parser, as per J. Earley, "An Efficient Context-Free
- # Parsing Algorithm", CACM 13(2), pp. 94-102. Also J. C. Earley,
- # "An Efficient Context-Free Parsing Algorithm", Ph.D. thesis,
- # Carnegie-Mellon University, August 1968. New formulation of
- # the parser according to J. Aycock, "Practical Earley Parsing
- # and the SPARK Toolkit", Ph.D. thesis, University of Victoria,
- # 2001, and J. Aycock and R. N. Horspool, "Practical Earley
- # Parsing", unpublished paper, 2001.
- #
-
- def __init__(self, start):
- self.rules = {}
- self.rule2func = {}
- self.rule2name = {}
- self.collectRules()
- self.augment(start)
- self.ruleschanged = 1
-
- _NULLABLE = '\e_'
- _START = 'START'
- _BOF = '|-'
-
- #
- # When pickling, take the time to generate the full state machine;
- # some information is then extraneous, too. Unfortunately we
- # can't save the rule2func map.
- #
- def __getstate__(self):
- if self.ruleschanged:
- #
- # XXX - duplicated from parse()
- #
- self.computeNull()
- self.newrules = {}
- self.new2old = {}
- self.makeNewRules()
- self.ruleschanged = 0
- self.edges, self.cores = {}, {}
- self.states = { 0: self.makeState0() }
- self.makeState(0, self._BOF)
- #
- # XXX - should find a better way to do this..
- #
- changes = 1
- while changes:
- changes = 0
- for k, v in self.edges.items():
- if v is None:
- state, sym = k
- if self.states.has_key(state):
- self.goto(state, sym)
- changes = 1
- rv = self.__dict__.copy()
- for s in self.states.values():
- del s.items
- del rv['rule2func']
- del rv['nullable']
- del rv['cores']
- return rv
-
- def __setstate__(self, D):
- self.rules = {}
- self.rule2func = {}
- self.rule2name = {}
- self.collectRules()
- start = D['rules'][self._START][0][1][1] # Blech.
- self.augment(start)
- D['rule2func'] = self.rule2func
- D['makeSet'] = self.makeSet_fast
- self.__dict__ = D
-
- #
- # A hook for GenericASTBuilder and GenericASTMatcher. Mess
- # thee not with this; nor shall thee toucheth the _preprocess
- # argument to addRule.
- #
- def preprocess(self, rule, func): return rule, func
-
- def addRule(self, doc, func, _preprocess=1):
- fn = func
- rules = string.split(doc)
-
- index = []
- for i in range(len(rules)):
- if rules[i] == '::=':
- index.append(i-1)
- index.append(len(rules))
-
- for i in range(len(index)-1):
- lhs = rules[index[i]]
- rhs = rules[index[i]+2:index[i+1]]
- rule = (lhs, tuple(rhs))
-
- if _preprocess:
- rule, fn = self.preprocess(rule, func)
-
- if self.rules.has_key(lhs):
- self.rules[lhs].append(rule)
- else:
- self.rules[lhs] = [ rule ]
- self.rule2func[rule] = fn
- self.rule2name[rule] = func.__name__[2:]
- self.ruleschanged = 1
-
- def collectRules(self):
- for name in _namelist(self):
- if name[:2] == 'p_':
- func = getattr(self, name)
- doc = func.__doc__
- self.addRule(doc, func)
-
- def augment(self, start):
- rule = '%s ::= %s %s' % (self._START, self._BOF, start)
- self.addRule(rule, lambda args: args[1], 0)
-
- def computeNull(self):
- self.nullable = {}
- tbd = []
-
- for rulelist in self.rules.values():
- lhs = rulelist[0][0]
- self.nullable[lhs] = 0
- for rule in rulelist:
- rhs = rule[1]
- if len(rhs) == 0:
- self.nullable[lhs] = 1
- continue
- #
- # We only need to consider rules which
- # consist entirely of nonterminal symbols.
- # This should be a savings on typical
- # grammars.
- #
- for sym in rhs:
- if not self.rules.has_key(sym):
- break
- else:
- tbd.append(rule)
- changes = 1
- while changes:
- changes = 0
- for lhs, rhs in tbd:
- if self.nullable[lhs]:
- continue
- for sym in rhs:
- if not self.nullable[sym]:
- break
- else:
- self.nullable[lhs] = 1
- changes = 1
-
- def makeState0(self):
- s0 = _State(0, [])
- for rule in self.newrules[self._START]:
- s0.items.append((rule, 0))
- return s0
-
- def finalState(self, tokens):
- #
- # Yuck.
- #
- if len(self.newrules[self._START]) == 2 and len(tokens) == 0:
- return 1
- start = self.rules[self._START][0][1][1]
- return self.goto(1, start)
-
- def makeNewRules(self):
- worklist = []
- for rulelist in self.rules.values():
- for rule in rulelist:
- worklist.append((rule, 0, 1, rule))
-
- for rule, i, candidate, oldrule in worklist:
- lhs, rhs = rule
- n = len(rhs)
- while i < n:
- sym = rhs[i]
- if not self.rules.has_key(sym) or \
- not self.nullable[sym]:
- candidate = 0
- i = i + 1
- continue
-
- newrhs = list(rhs)
- newrhs[i] = self._NULLABLE+sym
- newrule = (lhs, tuple(newrhs))
- worklist.append((newrule, i+1,
- candidate, oldrule))
- candidate = 0
- i = i + 1
- else:
- if candidate:
- lhs = self._NULLABLE+lhs
- rule = (lhs, rhs)
- if self.newrules.has_key(lhs):
- self.newrules[lhs].append(rule)
- else:
- self.newrules[lhs] = [ rule ]
- self.new2old[rule] = oldrule
-
- def typestring(self, token):
- return None
-
- def error(self, token):
- print "Syntax error at or near `%s' token" % token
- raise SystemExit
-
- def parse(self, tokens):
- sets = [ [(1,0), (2,0)] ]
- self.links = {}
-
- if self.ruleschanged:
- self.computeNull()
- self.newrules = {}
- self.new2old = {}
- self.makeNewRules()
- self.ruleschanged = 0
- self.edges, self.cores = {}, {}
- self.states = { 0: self.makeState0() }
- self.makeState(0, self._BOF)
-
- for i in xrange(len(tokens)):
- sets.append([])
-
- if sets[i] == []:
- break
- self.makeSet(tokens[i], sets, i)
- else:
- sets.append([])
- self.makeSet(None, sets, len(tokens))
-
- #_dump(tokens, sets, self.states)
-
- finalitem = (self.finalState(tokens), 0)
- if finalitem not in sets[-2]:
- if len(tokens) > 0:
- self.error(tokens[i-1])
- else:
- self.error(None)
-
- return self.buildTree(self._START, finalitem,
- tokens, len(sets)-2)
-
- def isnullable(self, sym):
- #
- # For symbols in G_e only. If we weren't supporting 1.5,
- # could just use sym.startswith().
- #
- return self._NULLABLE == sym[0:len(self._NULLABLE)]
-
- def skip(self, (lhs, rhs), pos=0):
- n = len(rhs)
- while pos < n:
- if not self.isnullable(rhs[pos]):
- break
- pos = pos + 1
- return pos
-
- def makeState(self, state, sym):
- assert sym is not None
- #
- # Compute \epsilon-kernel state's core and see if
- # it exists already.
- #
- kitems = []
- for rule, pos in self.states[state].items:
- lhs, rhs = rule
- if rhs[pos:pos+1] == (sym,):
- kitems.append((rule, self.skip(rule, pos+1)))
- core = kitems
-
- core.sort()
- tcore = tuple(core)
- if self.cores.has_key(tcore):
- return self.cores[tcore]
- #
- # Nope, doesn't exist. Compute it and the associated
- # \epsilon-nonkernel state together; we'll need it right away.
- #
- k = self.cores[tcore] = len(self.states)
- K, NK = _State(k, kitems), _State(k+1, [])
- self.states[k] = K
- predicted = {}
-
- edges = self.edges
- rules = self.newrules
- for X in K, NK:
- worklist = X.items
- for item in worklist:
- rule, pos = item
- lhs, rhs = rule
- if pos == len(rhs):
- X.complete.append(rule)
- continue
-
- nextSym = rhs[pos]
- key = (X.stateno, nextSym)
- if not rules.has_key(nextSym):
- if not edges.has_key(key):
- edges[key] = None
- X.T.append(nextSym)
- else:
- edges[key] = None
- if not predicted.has_key(nextSym):
- predicted[nextSym] = 1
- for prule in rules[nextSym]:
- ppos = self.skip(prule)
- new = (prule, ppos)
- NK.items.append(new)
- #
- # Problem: we know K needs generating, but we
- # don't yet know about NK. Can't commit anything
- # regarding NK to self.edges until we're sure. Should
- # we delay committing on both K and NK to avoid this
- # hacky code? This creates other problems..
- #
- if X is K:
- edges = {}
-
- if NK.items == []:
- return k
-
- #
- # Check for \epsilon-nonkernel's core. Unfortunately we
- # need to know the entire set of predicted nonterminals
- # to do this without accidentally duplicating states.
- #
- core = predicted.keys()
- core.sort()
- tcore = tuple(core)
- if self.cores.has_key(tcore):
- self.edges[(k, None)] = self.cores[tcore]
- return k
-
- nk = self.cores[tcore] = self.edges[(k, None)] = NK.stateno
- self.edges.update(edges)
- self.states[nk] = NK
- return k
-
- def goto(self, state, sym):
- key = (state, sym)
- if not self.edges.has_key(key):
- #
- # No transitions from state on sym.
- #
- return None
-
- rv = self.edges[key]
- if rv is None:
- #
- # Target state isn't generated yet. Remedy this.
- #
- rv = self.makeState(state, sym)
- self.edges[key] = rv
- return rv
-
- def gotoT(self, state, t):
- return [self.goto(state, t)]
-
- def gotoST(self, state, st):
- rv = []
- for t in self.states[state].T:
- if st == t:
- rv.append(self.goto(state, t))
- return rv
-
- def add(self, set, item, i=None, predecessor=None, causal=None):
- if predecessor is None:
- if item not in set:
- set.append(item)
- else:
- key = (item, i)
- if item not in set:
- self.links[key] = []
- set.append(item)
- self.links[key].append((predecessor, causal))
-
- def makeSet(self, token, sets, i):
- cur, next = sets[i], sets[i+1]
-
- ttype = token is not None and self.typestring(token) or None
- if ttype is not None:
- fn, arg = self.gotoT, ttype
- else:
- fn, arg = self.gotoST, token
-
- for item in cur:
- ptr = (item, i)
- state, parent = item
- add = fn(state, arg)
- for k in add:
- if k is not None:
- self.add(next, (k, parent), i+1, ptr)
- nk = self.goto(k, None)
- if nk is not None:
- self.add(next, (nk, i+1))
-
- if parent == i:
- continue
-
- for rule in self.states[state].complete:
- lhs, rhs = rule
- for pitem in sets[parent]:
- pstate, pparent = pitem
- k = self.goto(pstate, lhs)
- if k is not None:
- why = (item, i, rule)
- pptr = (pitem, parent)
- self.add(cur, (k, pparent),
- i, pptr, why)
- nk = self.goto(k, None)
- if nk is not None:
- self.add(cur, (nk, i))
-
- def makeSet_fast(self, token, sets, i):
- #
- # Call *only* when the entire state machine has been built!
- # It relies on self.edges being filled in completely, and
- # then duplicates and inlines code to boost speed at the
- # cost of extreme ugliness.
- #
- cur, next = sets[i], sets[i+1]
- ttype = token is not None and self.typestring(token) or None
-
- for item in cur:
- ptr = (item, i)
- state, parent = item
- if ttype is not None:
- k = self.edges.get((state, ttype), None)
- if k is not None:
- #self.add(next, (k, parent), i+1, ptr)
- #INLINED --v
- new = (k, parent)
- key = (new, i+1)
- if new not in next:
- self.links[key] = []
- next.append(new)
- self.links[key].append((ptr, None))
- #INLINED --^
- #nk = self.goto(k, None)
- nk = self.edges.get((k, None), None)
- if nk is not None:
- #self.add(next, (nk, i+1))
- #INLINED --v
- new = (nk, i+1)
- if new not in next:
- next.append(new)
- #INLINED --^
- else:
- add = self.gotoST(state, token)
- for k in add:
- if k is not None:
- self.add(next, (k, parent), i+1, ptr)
- #nk = self.goto(k, None)
- nk = self.edges.get((k, None), None)
- if nk is not None:
- self.add(next, (nk, i+1))
-
- if parent == i:
- continue
-
- for rule in self.states[state].complete:
- lhs, rhs = rule
- for pitem in sets[parent]:
- pstate, pparent = pitem
- #k = self.goto(pstate, lhs)
- k = self.edges.get((pstate, lhs), None)
- if k is not None:
- why = (item, i, rule)
- pptr = (pitem, parent)
- #self.add(cur, (k, pparent),
- # i, pptr, why)
- #INLINED --v
- new = (k, pparent)
- key = (new, i)
- if new not in cur:
- self.links[key] = []
- cur.append(new)
- self.links[key].append((pptr, why))
- #INLINED --^
- #nk = self.goto(k, None)
- nk = self.edges.get((k, None), None)
- if nk is not None:
- #self.add(cur, (nk, i))
- #INLINED --v
- new = (nk, i)
- if new not in cur:
- cur.append(new)
- #INLINED --^
-
- def predecessor(self, key, causal):
- for p, c in self.links[key]:
- if c == causal:
- return p
- assert 0
-
- def causal(self, key):
- links = self.links[key]
- if len(links) == 1:
- return links[0][1]
- choices = []
- rule2cause = {}
- for p, c in links:
- rule = c[2]
- choices.append(rule)
- rule2cause[rule] = c
- return rule2cause[self.ambiguity(choices)]
-
- def deriveEpsilon(self, nt):
- if len(self.newrules[nt]) > 1:
- rule = self.ambiguity(self.newrules[nt])
- else:
- rule = self.newrules[nt][0]
- #print rule
-
- rhs = rule[1]
- attr = [None] * len(rhs)
-
- for i in range(len(rhs)-1, -1, -1):
- attr[i] = self.deriveEpsilon(rhs[i])
- return self.rule2func[self.new2old[rule]](attr)
-
- def buildTree(self, nt, item, tokens, k):
- state, parent = item
-
- choices = []
- for rule in self.states[state].complete:
- if rule[0] == nt:
- choices.append(rule)
- rule = choices[0]
- if len(choices) > 1:
- rule = self.ambiguity(choices)
- #print rule
-
- rhs = rule[1]
- attr = [None] * len(rhs)
-
- for i in range(len(rhs)-1, -1, -1):
- sym = rhs[i]
- if not self.newrules.has_key(sym):
- if sym != self._BOF:
- attr[i] = tokens[k-1]
- key = (item, k)
- item, k = self.predecessor(key, None)
- #elif self.isnullable(sym):
- elif self._NULLABLE == sym[0:len(self._NULLABLE)]:
- attr[i] = self.deriveEpsilon(sym)
- else:
- key = (item, k)
- why = self.causal(key)
- attr[i] = self.buildTree(sym, why[0],
- tokens, why[1])
- item, k = self.predecessor(key, why)
- return self.rule2func[self.new2old[rule]](attr)
-
- def ambiguity(self, rules):
- #
- # XXX - problem here and in collectRules() if the same rule
- # appears in >1 method. Also undefined results if rules
- # causing the ambiguity appear in the same method.
- #
- sortlist = []
- name2index = {}
- for i in range(len(rules)):
- lhs, rhs = rule = rules[i]
- name = self.rule2name[self.new2old[rule]]
- sortlist.append((len(rhs), name))
- name2index[name] = i
- sortlist.sort()
- list = map(lambda (a,b): b, sortlist)
- return rules[name2index[self.resolve(list)]]
-
- def resolve(self, list):
- #
- # Resolve ambiguity in favor of the shortest RHS.
- # Since we walk the tree from the top down, this
- # should effectively resolve in favor of a "shift".
- #
- return list[0]
+ #
+ # An Earley parser, as per J. Earley, "An Efficient Context-Free
+ # Parsing Algorithm", CACM 13(2), pp. 94-102. Also J. C. Earley,
+ # "An Efficient Context-Free Parsing Algorithm", Ph.D. thesis,
+ # Carnegie-Mellon University, August 1968. New formulation of
+ # the parser according to J. Aycock, "Practical Earley Parsing
+ # and the SPARK Toolkit", Ph.D. thesis, University of Victoria,
+ # 2001, and J. Aycock and R. N. Horspool, "Practical Earley
+ # Parsing", unpublished paper, 2001.
+ #
+
+ def __init__(self, start):
+ self.rules = {}
+ self.rule2func = {}
+ self.rule2name = {}
+ self.collectRules()
+ self.augment(start)
+ self.ruleschanged = 1
+
+ _NULLABLE = '\e_'
+ _START = 'START'
+ _BOF = '|-'
+
+ #
+ # When pickling, take the time to generate the full state machine;
+ # some information is then extraneous, too. Unfortunately we
+ # can't save the rule2func map.
+ #
+ def __getstate__(self):
+ if self.ruleschanged:
+ #
+ # XXX - duplicated from parse()
+ #
+ self.computeNull()
+ self.newrules = {}
+ self.new2old = {}
+ self.makeNewRules()
+ self.ruleschanged = 0
+ self.edges, self.cores = {}, {}
+ self.states = { 0: self.makeState0() }
+ self.makeState(0, self._BOF)
+ #
+ # XXX - should find a better way to do this..
+ #
+ changes = 1
+ while changes:
+ changes = 0
+ for k, v in self.edges.items():
+ if v is None:
+ state, sym = k
+ if self.states.has_key(state):
+ self.goto(state, sym)
+ changes = 1
+ rv = self.__dict__.copy()
+ for s in self.states.values():
+ del s.items
+ del rv['rule2func']
+ del rv['nullable']
+ del rv['cores']
+ return rv
+
+ def __setstate__(self, D):
+ self.rules = {}
+ self.rule2func = {}
+ self.rule2name = {}
+ self.collectRules()
+ start = D['rules'][self._START][0][1][1] # Blech.
+ self.augment(start)
+ D['rule2func'] = self.rule2func
+ D['makeSet'] = self.makeSet_fast
+ self.__dict__ = D
+
+ #
+ # A hook for GenericASTBuilder and GenericASTMatcher. Mess
+ # thee not with this; nor shall thee toucheth the _preprocess
+ # argument to addRule.
+ #
+ def preprocess(self, rule, func): return rule, func
+
+ def addRule(self, doc, func, _preprocess=1):
+ fn = func
+ rules = string.split(doc)
+
+ index = []
+ for i in range(len(rules)):
+ if rules[i] == '::=':
+ index.append(i-1)
+ index.append(len(rules))
+
+ for i in range(len(index)-1):
+ lhs = rules[index[i]]
+ rhs = rules[index[i]+2:index[i+1]]
+ rule = (lhs, tuple(rhs))
+
+ if _preprocess:
+ rule, fn = self.preprocess(rule, func)
+
+ if self.rules.has_key(lhs):
+ self.rules[lhs].append(rule)
+ else:
+ self.rules[lhs] = [ rule ]
+ self.rule2func[rule] = fn
+ self.rule2name[rule] = func.__name__[2:]
+ self.ruleschanged = 1
+
+ def collectRules(self):
+ for name in _namelist(self):
+ if name[:2] == 'p_':
+ func = getattr(self, name)
+ doc = func.__doc__
+ self.addRule(doc, func)
+
+ def augment(self, start):
+ rule = '%s ::= %s %s' % (self._START, self._BOF, start)
+ self.addRule(rule, lambda args: args[1], 0)
+
+ def computeNull(self):
+ self.nullable = {}
+ tbd = []
+
+ for rulelist in self.rules.values():
+ lhs = rulelist[0][0]
+ self.nullable[lhs] = 0
+ for rule in rulelist:
+ rhs = rule[1]
+ if len(rhs) == 0:
+ self.nullable[lhs] = 1
+ continue
+ #
+ # We only need to consider rules which
+ # consist entirely of nonterminal symbols.
+ # This should be a savings on typical
+ # grammars.
+ #
+ for sym in rhs:
+ if not self.rules.has_key(sym):
+ break
+ else:
+ tbd.append(rule)
+ changes = 1
+ while changes:
+ changes = 0
+ for lhs, rhs in tbd:
+ if self.nullable[lhs]:
+ continue
+ for sym in rhs:
+ if not self.nullable[sym]:
+ break
+ else:
+ self.nullable[lhs] = 1
+ changes = 1
+
+ def makeState0(self):
+ s0 = _State(0, [])
+ for rule in self.newrules[self._START]:
+ s0.items.append((rule, 0))
+ return s0
+
+ def finalState(self, tokens):
+ #
+ # Yuck.
+ #
+ if len(self.newrules[self._START]) == 2 and len(tokens) == 0:
+ return 1
+ start = self.rules[self._START][0][1][1]
+ return self.goto(1, start)
+
+ def makeNewRules(self):
+ worklist = []
+ for rulelist in self.rules.values():
+ for rule in rulelist:
+ worklist.append((rule, 0, 1, rule))
+
+ for rule, i, candidate, oldrule in worklist:
+ lhs, rhs = rule
+ n = len(rhs)
+ while i < n:
+ sym = rhs[i]
+ if not self.rules.has_key(sym) or \
+ not self.nullable[sym]:
+ candidate = 0
+ i = i + 1
+ continue
+
+ newrhs = list(rhs)
+ newrhs[i] = self._NULLABLE+sym
+ newrule = (lhs, tuple(newrhs))
+ worklist.append((newrule, i+1,
+ candidate, oldrule))
+ candidate = 0
+ i = i + 1
+ else:
+ if candidate:
+ lhs = self._NULLABLE+lhs
+ rule = (lhs, rhs)
+ if self.newrules.has_key(lhs):
+ self.newrules[lhs].append(rule)
+ else:
+ self.newrules[lhs] = [ rule ]
+ self.new2old[rule] = oldrule
+
+ def typestring(self, token):
+ return None
+
+ def error(self, token):
+ print "Syntax error at or near `%s' token" % token
+ raise SystemExit
+
+ def parse(self, tokens):
+ sets = [ [(1,0), (2,0)] ]
+ self.links = {}
+
+ if self.ruleschanged:
+ self.computeNull()
+ self.newrules = {}
+ self.new2old = {}
+ self.makeNewRules()
+ self.ruleschanged = 0
+ self.edges, self.cores = {}, {}
+ self.states = { 0: self.makeState0() }
+ self.makeState(0, self._BOF)
+
+ for i in xrange(len(tokens)):
+ sets.append([])
+
+ if sets[i] == []:
+ break
+ self.makeSet(tokens[i], sets, i)
+ else:
+ sets.append([])
+ self.makeSet(None, sets, len(tokens))
+
+ #_dump(tokens, sets, self.states)
+
+ finalitem = (self.finalState(tokens), 0)
+ if finalitem not in sets[-2]:
+ if len(tokens) > 0:
+ self.error(tokens[i-1])
+ else:
+ self.error(None)
+
+ return self.buildTree(self._START, finalitem,
+ tokens, len(sets)-2)
+
+ def isnullable(self, sym):
+ #
+ # For symbols in G_e only. If we weren't supporting 1.5,
+ # could just use sym.startswith().
+ #
+ return self._NULLABLE == sym[0:len(self._NULLABLE)]
+
+ def skip(self, (lhs, rhs), pos=0):
+ n = len(rhs)
+ while pos < n:
+ if not self.isnullable(rhs[pos]):
+ break
+ pos = pos + 1
+ return pos
+
+ def makeState(self, state, sym):
+ assert sym is not None
+ #
+ # Compute \epsilon-kernel state's core and see if
+ # it exists already.
+ #
+ kitems = []
+ for rule, pos in self.states[state].items:
+ lhs, rhs = rule
+ if rhs[pos:pos+1] == (sym,):
+ kitems.append((rule, self.skip(rule, pos+1)))
+ core = kitems
+
+ core.sort()
+ tcore = tuple(core)
+ if self.cores.has_key(tcore):
+ return self.cores[tcore]
+ #
+ # Nope, doesn't exist. Compute it and the associated
+ # \epsilon-nonkernel state together; we'll need it right away.
+ #
+ k = self.cores[tcore] = len(self.states)
+ K, NK = _State(k, kitems), _State(k+1, [])
+ self.states[k] = K
+ predicted = {}
+
+ edges = self.edges
+ rules = self.newrules
+ for X in K, NK:
+ worklist = X.items
+ for item in worklist:
+ rule, pos = item
+ lhs, rhs = rule
+ if pos == len(rhs):
+ X.complete.append(rule)
+ continue
+
+ nextSym = rhs[pos]
+ key = (X.stateno, nextSym)
+ if not rules.has_key(nextSym):
+ if not edges.has_key(key):
+ edges[key] = None
+ X.T.append(nextSym)
+ else:
+ edges[key] = None
+ if not predicted.has_key(nextSym):
+ predicted[nextSym] = 1
+ for prule in rules[nextSym]:
+ ppos = self.skip(prule)
+ new = (prule, ppos)
+ NK.items.append(new)
+ #
+ # Problem: we know K needs generating, but we
+ # don't yet know about NK. Can't commit anything
+ # regarding NK to self.edges until we're sure. Should
+ # we delay committing on both K and NK to avoid this
+ # hacky code? This creates other problems..
+ #
+ if X is K:
+ edges = {}
+
+ if NK.items == []:
+ return k
+
+ #
+ # Check for \epsilon-nonkernel's core. Unfortunately we
+ # need to know the entire set of predicted nonterminals
+ # to do this without accidentally duplicating states.
+ #
+ core = predicted.keys()
+ core.sort()
+ tcore = tuple(core)
+ if self.cores.has_key(tcore):
+ self.edges[(k, None)] = self.cores[tcore]
+ return k
+
+ nk = self.cores[tcore] = self.edges[(k, None)] = NK.stateno
+ self.edges.update(edges)
+ self.states[nk] = NK
+ return k
+
+ def goto(self, state, sym):
+ key = (state, sym)
+ if not self.edges.has_key(key):
+ #
+ # No transitions from state on sym.
+ #
+ return None
+
+ rv = self.edges[key]
+ if rv is None:
+ #
+ # Target state isn't generated yet. Remedy this.
+ #
+ rv = self.makeState(state, sym)
+ self.edges[key] = rv
+ return rv
+
+ def gotoT(self, state, t):
+ return [self.goto(state, t)]
+
+ def gotoST(self, state, st):
+ rv = []
+ for t in self.states[state].T:
+ if st == t:
+ rv.append(self.goto(state, t))
+ return rv
+
+ def add(self, set, item, i=None, predecessor=None, causal=None):
+ if predecessor is None:
+ if item not in set:
+ set.append(item)
+ else:
+ key = (item, i)
+ if item not in set:
+ self.links[key] = []
+ set.append(item)
+ self.links[key].append((predecessor, causal))
+
+ def makeSet(self, token, sets, i):
+ cur, next = sets[i], sets[i+1]
+
+ ttype = token is not None and self.typestring(token) or None
+ if ttype is not None:
+ fn, arg = self.gotoT, ttype
+ else:
+ fn, arg = self.gotoST, token
+
+ for item in cur:
+ ptr = (item, i)
+ state, parent = item
+ add = fn(state, arg)
+ for k in add:
+ if k is not None:
+ self.add(next, (k, parent), i+1, ptr)
+ nk = self.goto(k, None)
+ if nk is not None:
+ self.add(next, (nk, i+1))
+
+ if parent == i:
+ continue
+
+ for rule in self.states[state].complete:
+ lhs, rhs = rule
+ for pitem in sets[parent]:
+ pstate, pparent = pitem
+ k = self.goto(pstate, lhs)
+ if k is not None:
+ why = (item, i, rule)
+ pptr = (pitem, parent)
+ self.add(cur, (k, pparent),
+ i, pptr, why)
+ nk = self.goto(k, None)
+ if nk is not None:
+ self.add(cur, (nk, i))
+
+ def makeSet_fast(self, token, sets, i):
+ #
+ # Call *only* when the entire state machine has been built!
+ # It relies on self.edges being filled in completely, and
+ # then duplicates and inlines code to boost speed at the
+ # cost of extreme ugliness.
+ #
+ cur, next = sets[i], sets[i+1]
+ ttype = token is not None and self.typestring(token) or None
+
+ for item in cur:
+ ptr = (item, i)
+ state, parent = item
+ if ttype is not None:
+ k = self.edges.get((state, ttype), None)
+ if k is not None:
+ #self.add(next, (k, parent), i+1, ptr)
+ #INLINED --v
+ new = (k, parent)
+ key = (new, i+1)
+ if new not in next:
+ self.links[key] = []
+ next.append(new)
+ self.links[key].append((ptr, None))
+ #INLINED --^
+ #nk = self.goto(k, None)
+ nk = self.edges.get((k, None), None)
+ if nk is not None:
+ #self.add(next, (nk, i+1))
+ #INLINED --v
+ new = (nk, i+1)
+ if new not in next:
+ next.append(new)
+ #INLINED --^
+ else:
+ add = self.gotoST(state, token)
+ for k in add:
+ if k is not None:
+ self.add(next, (k, parent), i+1, ptr)
+ #nk = self.goto(k, None)
+ nk = self.edges.get((k, None), None)
+ if nk is not None:
+ self.add(next, (nk, i+1))
+
+ if parent == i:
+ continue
+
+ for rule in self.states[state].complete:
+ lhs, rhs = rule
+ for pitem in sets[parent]:
+ pstate, pparent = pitem
+ #k = self.goto(pstate, lhs)
+ k = self.edges.get((pstate, lhs), None)
+ if k is not None:
+ why = (item, i, rule)
+ pptr = (pitem, parent)
+ #self.add(cur, (k, pparent),
+ # i, pptr, why)
+ #INLINED --v
+ new = (k, pparent)
+ key = (new, i)
+ if new not in cur:
+ self.links[key] = []
+ cur.append(new)
+ self.links[key].append((pptr, why))
+ #INLINED --^
+ #nk = self.goto(k, None)
+ nk = self.edges.get((k, None), None)
+ if nk is not None:
+ #self.add(cur, (nk, i))
+ #INLINED --v
+ new = (nk, i)
+ if new not in cur:
+ cur.append(new)
+ #INLINED --^
+
+ def predecessor(self, key, causal):
+ for p, c in self.links[key]:
+ if c == causal:
+ return p
+ assert 0
+
+ def causal(self, key):
+ links = self.links[key]
+ if len(links) == 1:
+ return links[0][1]
+ choices = []
+ rule2cause = {}
+ for p, c in links:
+ rule = c[2]
+ choices.append(rule)
+ rule2cause[rule] = c
+ return rule2cause[self.ambiguity(choices)]
+
+ def deriveEpsilon(self, nt):
+ if len(self.newrules[nt]) > 1:
+ rule = self.ambiguity(self.newrules[nt])
+ else:
+ rule = self.newrules[nt][0]
+ #print rule
+
+ rhs = rule[1]
+ attr = [None] * len(rhs)
+
+ for i in range(len(rhs)-1, -1, -1):
+ attr[i] = self.deriveEpsilon(rhs[i])
+ return self.rule2func[self.new2old[rule]](attr)
+
+ def buildTree(self, nt, item, tokens, k):
+ state, parent = item
+
+ choices = []
+ for rule in self.states[state].complete:
+ if rule[0] == nt:
+ choices.append(rule)
+ rule = choices[0]
+ if len(choices) > 1:
+ rule = self.ambiguity(choices)
+ #print rule
+
+ rhs = rule[1]
+ attr = [None] * len(rhs)
+
+ for i in range(len(rhs)-1, -1, -1):
+ sym = rhs[i]
+ if not self.newrules.has_key(sym):
+ if sym != self._BOF:
+ attr[i] = tokens[k-1]
+ key = (item, k)
+ item, k = self.predecessor(key, None)
+ #elif self.isnullable(sym):
+ elif self._NULLABLE == sym[0:len(self._NULLABLE)]:
+ attr[i] = self.deriveEpsilon(sym)
+ else:
+ key = (item, k)
+ why = self.causal(key)
+ attr[i] = self.buildTree(sym, why[0],
+ tokens, why[1])
+ item, k = self.predecessor(key, why)
+ return self.rule2func[self.new2old[rule]](attr)
+
+ def ambiguity(self, rules):
+ #
+ # XXX - problem here and in collectRules() if the same rule
+ # appears in >1 method. Also undefined results if rules
+ # causing the ambiguity appear in the same method.
+ #
+ sortlist = []
+ name2index = {}
+ for i in range(len(rules)):
+ lhs, rhs = rule = rules[i]
+ name = self.rule2name[self.new2old[rule]]
+ sortlist.append((len(rhs), name))
+ name2index[name] = i
+ sortlist.sort()
+ list = map(lambda (a,b): b, sortlist)
+ return rules[name2index[self.resolve(list)]]
+
+ def resolve(self, list):
+ #
+ # Resolve ambiguity in favor of the shortest RHS.
+ # Since we walk the tree from the top down, this
+ # should effectively resolve in favor of a "shift".
+ #
+ return list[0]
#
# GenericASTBuilder automagically constructs a concrete/abstract syntax tree
@@ -681,32 +681,32 @@ class GenericParser:
#
class GenericASTBuilder(GenericParser):
- def __init__(self, AST, start):
- GenericParser.__init__(self, start)
- self.AST = AST
-
- def preprocess(self, rule, func):
- rebind = lambda lhs, self=self: \
- lambda args, lhs=lhs, self=self: \
- self.buildASTNode(args, lhs)
- lhs, rhs = rule
- return rule, rebind(lhs)
-
- def buildASTNode(self, args, lhs):
- children = []
- for arg in args:
- if isinstance(arg, self.AST):
- children.append(arg)
- else:
- children.append(self.terminal(arg))
- return self.nonterminal(lhs, children)
-
- def terminal(self, token): return token
-
- def nonterminal(self, type, args):
- rv = self.AST(type)
- rv[:len(args)] = args
- return rv
+ def __init__(self, AST, start):
+ GenericParser.__init__(self, start)
+ self.AST = AST
+
+ def preprocess(self, rule, func):
+ rebind = lambda lhs, self=self: \
+ lambda args, lhs=lhs, self=self: \
+ self.buildASTNode(args, lhs)
+ lhs, rhs = rule
+ return rule, rebind(lhs)
+
+ def buildASTNode(self, args, lhs):
+ children = []
+ for arg in args:
+ if isinstance(arg, self.AST):
+ children.append(arg)
+ else:
+ children.append(self.terminal(arg))
+ return self.nonterminal(lhs, children)
+
+ def terminal(self, token): return token
+
+ def nonterminal(self, type, args):
+ rv = self.AST(type)
+ rv[:len(args)] = args
+ return rv
#
# GenericASTTraversal is a Visitor pattern according to Design Patterns. For
@@ -719,57 +719,57 @@ class GenericASTBuilder(GenericParser):
#
class GenericASTTraversalPruningException:
- pass
+ pass
class GenericASTTraversal:
- def __init__(self, ast):
- self.ast = ast
+ def __init__(self, ast):
+ self.ast = ast
- def typestring(self, node):
- return node.type
+ def typestring(self, node):
+ return node.type
- def prune(self):
- raise GenericASTTraversalPruningException
+ def prune(self):
+ raise GenericASTTraversalPruningException
- def preorder(self, node=None):
- if node is None:
- node = self.ast
+ def preorder(self, node=None):
+ if node is None:
+ node = self.ast
- try:
- name = 'n_' + self.typestring(node)
- if hasattr(self, name):
- func = getattr(self, name)
- func(node)
- else:
- self.default(node)
- except GenericASTTraversalPruningException:
- return
+ try:
+ name = 'n_' + self.typestring(node)
+ if hasattr(self, name):
+ func = getattr(self, name)
+ func(node)
+ else:
+ self.default(node)
+ except GenericASTTraversalPruningException:
+ return
- for kid in node:
- self.preorder(kid)
+ for kid in node:
+ self.preorder(kid)
- name = name + '_exit'
- if hasattr(self, name):
- func = getattr(self, name)
- func(node)
+ name = name + '_exit'
+ if hasattr(self, name):
+ func = getattr(self, name)
+ func(node)
- def postorder(self, node=None):
- if node is None:
- node = self.ast
+ def postorder(self, node=None):
+ if node is None:
+ node = self.ast
- for kid in node:
- self.postorder(kid)
+ for kid in node:
+ self.postorder(kid)
- name = 'n_' + self.typestring(node)
- if hasattr(self, name):
- func = getattr(self, name)
- func(node)
- else:
- self.default(node)
+ name = 'n_' + self.typestring(node)
+ if hasattr(self, name):
+ func = getattr(self, name)
+ func(node)
+ else:
+ self.default(node)
- def default(self, node):
- pass
+ def default(self, node):
+ pass
#
# GenericASTMatcher. AST nodes must have "__getitem__" and "__cmp__"
@@ -779,62 +779,62 @@ class GenericASTTraversal:
#
class GenericASTMatcher(GenericParser):
- def __init__(self, start, ast):
- GenericParser.__init__(self, start)
- self.ast = ast
-
- def preprocess(self, rule, func):
- rebind = lambda func, self=self: \
- lambda args, func=func, self=self: \
- self.foundMatch(args, func)
- lhs, rhs = rule
- rhslist = list(rhs)
- rhslist.reverse()
-
- return (lhs, tuple(rhslist)), rebind(func)
-
- def foundMatch(self, args, func):
- func(args[-1])
- return args[-1]
-
- def match_r(self, node):
- self.input.insert(0, node)
- children = 0
-
- for child in node:
- if children == 0:
- self.input.insert(0, '(')
- children = children + 1
- self.match_r(child)
-
- if children > 0:
- self.input.insert(0, ')')
-
- def match(self, ast=None):
- if ast is None:
- ast = self.ast
- self.input = []
-
- self.match_r(ast)
- self.parse(self.input)
-
- def resolve(self, list):
- #
- # Resolve ambiguity in favor of the longest RHS.
- #
- return list[-1]
+ def __init__(self, start, ast):
+ GenericParser.__init__(self, start)
+ self.ast = ast
+
+ def preprocess(self, rule, func):
+ rebind = lambda func, self=self: \
+ lambda args, func=func, self=self: \
+ self.foundMatch(args, func)
+ lhs, rhs = rule
+ rhslist = list(rhs)
+ rhslist.reverse()
+
+ return (lhs, tuple(rhslist)), rebind(func)
+
+ def foundMatch(self, args, func):
+ func(args[-1])
+ return args[-1]
+
+ def match_r(self, node):
+ self.input.insert(0, node)
+ children = 0
+
+ for child in node:
+ if children == 0:
+ self.input.insert(0, '(')
+ children = children + 1
+ self.match_r(child)
+
+ if children > 0:
+ self.input.insert(0, ')')
+
+ def match(self, ast=None):
+ if ast is None:
+ ast = self.ast
+ self.input = []
+
+ self.match_r(ast)
+ self.parse(self.input)
+
+ def resolve(self, list):
+ #
+ # Resolve ambiguity in favor of the longest RHS.
+ #
+ return list[-1]
def _dump(tokens, sets, states):
- for i in range(len(sets)):
- print 'set', i
- for item in sets[i]:
- print '\t', item
- for (lhs, rhs), pos in states[item[0]].items:
- print '\t\t', lhs, '::=',
- print string.join(rhs[:pos]),
- print '.',
- print string.join(rhs[pos:])
- if i < len(tokens):
- print
- print 'token', str(tokens[i])
- print
+ for i in range(len(sets)):
+ print 'set', i
+ for item in sets[i]:
+ print '\t', item
+ for (lhs, rhs), pos in states[item[0]].items:
+ print '\t\t', lhs, '::=',
+ print string.join(rhs[:pos]),
+ print '.',
+ print string.join(rhs[pos:])
+ if i < len(tokens):
+ print
+ print 'token', str(tokens[i])
+ print