diff options
Diffstat (limited to 'yapps')
| -rw-r--r-- | yapps/__init__.py | 1 | ||||
| -rw-r--r-- | yapps/grammar.py | 211 | ||||
| -rw-r--r-- | yapps/parsetree.py | 673 | ||||
| -rw-r--r-- | yapps/runtime.py | 442 |
4 files changed, 0 insertions, 1327 deletions
diff --git a/yapps/__init__.py b/yapps/__init__.py deleted file mode 100644 index 1bb8bf6..0000000 --- a/yapps/__init__.py +++ /dev/null @@ -1 +0,0 @@ -# empty diff --git a/yapps/grammar.py b/yapps/grammar.py deleted file mode 100644 index 1714344..0000000 --- a/yapps/grammar.py +++ /dev/null @@ -1,211 +0,0 @@ -# grammar.py, part of Yapps 2 - yet another python parser system -# Copyright 1999-2003 by Amit J. Patel <amitp@cs.stanford.edu> -# -# This version of the Yapps 2 grammar can be distributed under the -# terms of the MIT open source license, either found in the LICENSE -# file included with the Yapps distribution -# <http://theory.stanford.edu/~amitp/yapps/> or at -# <http://www.opensource.org/licenses/mit-license.php> -# - -"""Parser for Yapps grammars. - -This file defines the grammar of Yapps grammars. Naturally, it is -implemented in Yapps. The grammar.py module needed by Yapps is built -by running Yapps on yapps_grammar.g. (Holy circularity, Batman!) - -""" - -import sys, re -from yapps import parsetree - -###################################################################### -def cleanup_choice(rule, lst): - if len(lst) == 0: return Sequence(rule, []) - if len(lst) == 1: return lst[0] - return parsetree.Choice(rule, *tuple(lst)) - -def cleanup_sequence(rule, lst): - if len(lst) == 1: return lst[0] - return parsetree.Sequence(rule, *tuple(lst)) - -def resolve_name(rule, tokens, id, args): - if id in [x[0] for x in tokens]: - # It's a token - if args: - print 'Warning: ignoring parameters on TOKEN %s<<%s>>' % (id, args) - return parsetree.Terminal(rule, id) - else: - # It's a name, so assume it's a nonterminal - return parsetree.NonTerminal(rule, id, args) - - -# Begin -- grammar generated by Yapps -import sys, re -from yapps import runtime - -class ParserDescriptionScanner(runtime.Scanner): - patterns = [ - ('"rule"', re.compile('rule')), - ('"ignore"', re.compile('ignore')), - ('"token"', re.compile('token')), - ('"option"', re.compile('option')), - ('":"', re.compile(':')), - ('"parser"', re.compile('parser')), - ('[ \t\r\n]+', re.compile('[ \t\r\n]+')), - ('#.*?\r?\n', re.compile('#.*?\r?\n')), - ('EOF', re.compile('$')), - ('ATTR', re.compile('<<.+?>>')), - ('STMT', re.compile('{{.+?}}')), - ('ID', re.compile('[a-zA-Z_][a-zA-Z_0-9]*')), - ('STR', re.compile('[rR]?\'([^\\n\'\\\\]|\\\\.)*\'|[rR]?"([^\\n"\\\\]|\\\\.)*"')), - ('LP', re.compile('\\(')), - ('RP', re.compile('\\)')), - ('LB', re.compile('\\[')), - ('RB', re.compile('\\]')), - ('OR', re.compile('[|]')), - ('STAR', re.compile('[*]')), - ('PLUS', re.compile('[+]')), - ('QUEST', re.compile('[?]')), - ('COLON', re.compile(':')), - ] - def __init__(self, str,*args,**kw): - runtime.Scanner.__init__(self,None,{'[ \t\r\n]+':None,'#.*?\r?\n':None,},str,*args,**kw) - -class ParserDescription(runtime.Parser): - Context = runtime.Context - def Parser(self, _parent=None): - _context = self.Context(_parent, self._scanner, 'Parser', []) - self._scan('"parser"', context=_context) - ID = self._scan('ID', context=_context) - self._scan('":"', context=_context) - Options = self.Options(_context) - Tokens = self.Tokens(_context) - Rules = self.Rules(Tokens, _context) - EOF = self._scan('EOF', context=_context) - return parsetree.Generator(ID,Options,Tokens,Rules) - - def Options(self, _parent=None): - _context = self.Context(_parent, self._scanner, 'Options', []) - opt = {} - while self._peek('"option"', '"token"', '"ignore"', 'EOF', '"rule"', context=_context) == '"option"': - self._scan('"option"', context=_context) - self._scan('":"', context=_context) - Str = self.Str(_context) - opt[Str] = 1 - return opt - - def Tokens(self, _parent=None): - _context = self.Context(_parent, self._scanner, 'Tokens', []) - tok = [] - while self._peek('"token"', '"ignore"', 'EOF', '"rule"', context=_context) in ['"token"', '"ignore"']: - _token = self._peek('"token"', '"ignore"', context=_context) - if _token == '"token"': - self._scan('"token"', context=_context) - ID = self._scan('ID', context=_context) - self._scan('":"', context=_context) - Str = self.Str(_context) - tok.append( (ID,Str) ) - else: # == '"ignore"' - self._scan('"ignore"', context=_context) - self._scan('":"', context=_context) - Str = self.Str(_context) - ign = ('#ignore',Str) - if self._peek('STMT', '"token"', '"ignore"', 'EOF', '"rule"', context=_context) == 'STMT': - STMT = self._scan('STMT', context=_context) - ign = ign + (STMT[2:-2],) - tok.append( ign ) - return tok - - def Rules(self, tokens, _parent=None): - _context = self.Context(_parent, self._scanner, 'Rules', [tokens]) - rul = [] - while self._peek('"rule"', 'EOF', context=_context) == '"rule"': - self._scan('"rule"', context=_context) - ID = self._scan('ID', context=_context) - OptParam = self.OptParam(_context) - self._scan('":"', context=_context) - ClauseA = self.ClauseA(ID, tokens, _context) - rul.append( (ID, OptParam, ClauseA) ) - return rul - - def ClauseA(self, rule, tokens, _parent=None): - _context = self.Context(_parent, self._scanner, 'ClauseA', [rule, tokens]) - ClauseB = self.ClauseB(rule,tokens, _context) - v = [ClauseB] - while self._peek('OR', 'RP', 'RB', '"rule"', 'EOF', context=_context) == 'OR': - OR = self._scan('OR', context=_context) - ClauseB = self.ClauseB(rule,tokens, _context) - v.append(ClauseB) - return cleanup_choice(rule,v) - - def ClauseB(self, rule,tokens, _parent=None): - _context = self.Context(_parent, self._scanner, 'ClauseB', [rule,tokens]) - v = [] - while self._peek('STR', 'ID', 'LP', 'LB', 'STMT', 'OR', 'RP', 'RB', '"rule"', 'EOF', context=_context) in ['STR', 'ID', 'LP', 'LB', 'STMT']: - ClauseC = self.ClauseC(rule,tokens, _context) - v.append(ClauseC) - return cleanup_sequence(rule, v) - - def ClauseC(self, rule,tokens, _parent=None): - _context = self.Context(_parent, self._scanner, 'ClauseC', [rule,tokens]) - ClauseD = self.ClauseD(rule,tokens, _context) - _token = self._peek('PLUS', 'STAR', 'QUEST', 'STR', 'ID', 'LP', 'LB', 'STMT', 'OR', 'RP', 'RB', '"rule"', 'EOF', context=_context) - if _token == 'PLUS': - PLUS = self._scan('PLUS', context=_context) - return parsetree.Plus(rule, ClauseD) - elif _token == 'STAR': - STAR = self._scan('STAR', context=_context) - return parsetree.Star(rule, ClauseD) - elif _token == 'QUEST': - QUEST = self._scan('QUEST', context=_context) - return parsetree.Option(rule, ClauseD) - else: - return ClauseD - - def ClauseD(self, rule,tokens, _parent=None): - _context = self.Context(_parent, self._scanner, 'ClauseD', [rule,tokens]) - _token = self._peek('STR', 'ID', 'LP', 'LB', 'STMT', context=_context) - if _token == 'STR': - STR = self._scan('STR', context=_context) - t = (STR, eval(STR,{},{})) - if t not in tokens: tokens.insert( 0, t ) - return parsetree.Terminal(rule, STR) - elif _token == 'ID': - ID = self._scan('ID', context=_context) - OptParam = self.OptParam(_context) - return resolve_name(rule,tokens, ID, OptParam) - elif _token == 'LP': - LP = self._scan('LP', context=_context) - ClauseA = self.ClauseA(rule,tokens, _context) - RP = self._scan('RP', context=_context) - return ClauseA - elif _token == 'LB': - LB = self._scan('LB', context=_context) - ClauseA = self.ClauseA(rule,tokens, _context) - RB = self._scan('RB', context=_context) - return parsetree.Option(rule, ClauseA) - else: # == 'STMT' - STMT = self._scan('STMT', context=_context) - return parsetree.Eval(rule, STMT[2:-2]) - - def OptParam(self, _parent=None): - _context = self.Context(_parent, self._scanner, 'OptParam', []) - if self._peek('ATTR', '":"', 'PLUS', 'STAR', 'QUEST', 'STR', 'ID', 'LP', 'LB', 'STMT', 'OR', 'RP', 'RB', '"rule"', 'EOF', context=_context) == 'ATTR': - ATTR = self._scan('ATTR', context=_context) - return ATTR[2:-2] - return '' - - def Str(self, _parent=None): - _context = self.Context(_parent, self._scanner, 'Str', []) - STR = self._scan('STR', context=_context) - return eval(STR,{},{}) - - -def parse(rule, text): - P = ParserDescription(ParserDescriptionScanner(text)) - return runtime.wrap_error_reporter(P, rule) - -# End -- grammar generated by Yapps - - diff --git a/yapps/parsetree.py b/yapps/parsetree.py deleted file mode 100644 index e5e0ae0..0000000 --- a/yapps/parsetree.py +++ /dev/null @@ -1,673 +0,0 @@ -# parsetree.py, part of Yapps 2 - yet another python parser system -# Copyright 1999-2003 by Amit J. Patel <amitp@cs.stanford.edu> -# -# This version of the Yapps 2 Runtime can be distributed under the -# terms of the MIT open source license, either found in the LICENSE file -# included with the Yapps distribution -# <http://theory.stanford.edu/~amitp/yapps/> or at -# <http://www.opensource.org/licenses/mit-license.php> -# - -"""Classes used to represent parse trees and generate output. - -This module defines the Generator class, which drives the generation -of Python output from a grammar parse tree. It also defines nodes -used to represent the parse tree; they are derived from class Node. - -The main logic of Yapps is in this module. -""" - -import sys, re - -###################################################################### -INDENT = ' '*4 -class Generator: - - # TODO: many of the methods here should be class methods, not instance methods - - def __init__(self, name, options, tokens, rules): - self.change_count = 0 - self.name = name - self.options = options - self.preparser = '' - self.postparser = None - - self.tokens = {} # Map from tokens to regexps - self.ignore = {} # List of token names to ignore in parsing, map to statements - self.terminals = [] # List of token names (to maintain ordering) - for t in tokens: - if len(t) == 3: - n,t,s = t - else: - n,t = t - s = None - - if n == '#ignore': - n = t - self.ignore[n] = s - if n in self.tokens.keys() and self.tokens[n] != t: - print >>sys.stderr, 'Warning: token %s defined more than once.' % n - self.tokens[n] = t - self.terminals.append(n) - - self.rules = {} # Map from rule names to parser nodes - self.params = {} # Map from rule names to parameters - self.goals = [] # List of rule names (to maintain ordering) - for n,p,r in rules: - self.params[n] = p - self.rules[n] = r - self.goals.append(n) - - self.output = sys.stdout - - def has_option(self, name): - return self.options.get(name, 0) - - def non_ignored_tokens(self): - return [x for x in self.terminals if x not in self.ignore] - - def changed(self): - """Increments the change count. - - >>> t = Generator('', [], [], []) - >>> old_count = t.change_count - >>> t.changed() - >>> assert t.change_count == old_count + 1 - """ - self.change_count = 1+self.change_count - - def set_subtract(self, a, b): - """Returns the elements of a that are not in b. - - >>> t = Generator('', [], [], []) - >>> t.set_subtract([], []) - [] - >>> t.set_subtract([1, 2], [1, 2]) - [] - >>> t.set_subtract([1, 2, 3], [2]) - [1, 3] - >>> t.set_subtract([1], [2, 3, 4]) - [1] - """ - result = [] - for x in a: - if x not in b: - result.append(x) - return result - - def subset(self, a, b): - """True iff all elements of sequence a are inside sequence b - - >>> t = Generator('', [], [], []) - >>> t.subset([], [1, 2, 3]) - 1 - >>> t.subset([1, 2, 3], []) - 0 - >>> t.subset([1], [1, 2, 3]) - 1 - >>> t.subset([3, 2, 1], [1, 2, 3]) - 1 - >>> t.subset([1, 1, 1], [1, 2, 3]) - 1 - >>> t.subset([1, 2, 3], [1, 1, 1]) - 0 - """ - for x in a: - if x not in b: - return 0 - return 1 - - def equal_set(self, a, b): - """True iff subset(a, b) and subset(b, a) - - >>> t = Generator('', [], [], []) - >>> a_set = [1, 2, 3] - >>> t.equal_set(a_set, a_set) - 1 - >>> t.equal_set(a_set, a_set[:]) - 1 - >>> t.equal_set([], a_set) - 0 - >>> t.equal_set([1, 2, 3], [3, 2, 1]) - 1 - """ - if len(a) != len(b): return 0 - if a == b: return 1 - return self.subset(a, b) and self.subset(b, a) - - def add_to(self, parent, additions): - "Modify _parent_ to include all elements in _additions_" - for x in additions: - if x not in parent: - parent.append(x) - self.changed() - - def equate(self, a, b): - """Extend (a) and (b) so that they contain each others' elements. - - >>> t = Generator('', [], [], []) - >>> a = [1, 2] - >>> b = [2, 3] - >>> t.equate(a, b) - >>> a - [1, 2, 3] - >>> b - [2, 3, 1] - """ - self.add_to(a, b) - self.add_to(b, a) - - def write(self, *args): - for a in args: - self.output.write(a) - - def in_test(self, expr, full, set): - """Generate a test of (expr) being in (set), where (set) is a subset of (full) - - expr is a string (Python expression) - set is a list of values (which will be converted with repr) - full is the list of all values expr could possibly evaluate to - - >>> t = Generator('', [], [], []) - >>> t.in_test('x', [1,2,3,4], []) - '0' - >>> t.in_test('x', [1,2,3,4], [1,2,3,4]) - '1' - >>> t.in_test('x', [1,2,3,4], [1]) - 'x == 1' - >>> t.in_test('a+b', [1,2,3,4], [1,2]) - 'a+b in [1, 2]' - >>> t.in_test('x', [1,2,3,4,5], [1,2,3]) - 'x not in [4, 5]' - >>> t.in_test('x', [1,2,3,4,5], [1,2,3,4]) - 'x != 5' - """ - - if not set: return '0' - if len(set) == 1: return '%s == %s' % (expr, repr(set[0])) - if full and len(set) > len(full)/2: - # Reverse the sense of the test. - not_set = [x for x in full if x not in set] - return self.not_in_test(expr, full, not_set) - return '%s in %s' % (expr, repr(set)) - - def not_in_test(self, expr, full, set): - """Like in_test, but the reverse test.""" - if not set: return '1' - if len(set) == 1: return '%s != %s' % (expr, repr(set[0])) - return '%s not in %s' % (expr, repr(set)) - - def peek_call(self, a): - """Generate a call to scan for a token in the set 'a'""" - assert type(a) == type([]) - a_set = (repr(a)[1:-1]) - if self.equal_set(a, self.non_ignored_tokens()): a_set = '' - if self.has_option('context-insensitive-scanner'): a_set = '' - if a_set: a_set += "," - - return 'self._peek(%s context=_context)' % a_set - - def peek_test(self, a, b): - """Generate a call to test whether the next token (which could be any of - the elements in a) is in the set b.""" - if self.subset(a, b): return '1' - if self.has_option('context-insensitive-scanner'): a = self.non_ignored_tokens() - return self.in_test(self.peek_call(a), a, b) - - def not_peek_test(self, a, b): - """Like peek_test, but the opposite sense.""" - if self.subset(a, b): return '0' - return self.not_in_test(self.peek_call(a), a, b) - - def calculate(self): - """The main loop to compute the epsilon, first, follow sets. - The loop continues until the sets converge. This works because - each set can only get larger, so when they stop getting larger, - we're done.""" - # First we determine whether a rule accepts epsilon (the empty sequence) - while 1: - for r in self.goals: - self.rules[r].setup(self) - if self.change_count == 0: break - self.change_count = 0 - - # Now we compute the first/follow sets - while 1: - for r in self.goals: - self.rules[r].update(self) - if self.change_count == 0: break - self.change_count = 0 - - def dump_information(self): - """Display the grammar in somewhat human-readable form.""" - self.calculate() - for r in self.goals: - print ' _____' + '_'*len(r) - print ('___/Rule '+r+'\\' + '_'*80)[:79] - queue = [self.rules[r]] - while queue: - top = queue[0] - del queue[0] - - print 'Rule', repr(top), 'of class', top.__class__.__name__ - top.first.sort() - top.follow.sort() - eps = [] - if top.accepts_epsilon: eps = ['(null)'] - print ' FIRST:', ', '.join(top.first+eps) - print ' FOLLOW:', ', '.join(top.follow) - for x in top.get_children(): queue.append(x) - - def repr_ignore(self): - out="{" - for t,s in self.ignore.iteritems(): - if s is None: s=repr(s) - out += "%s:%s," % (repr(t),s) - out += "}" - return out - - def generate_output(self): - self.calculate() - self.write(self.preparser) - self.write("# Begin -- grammar generated by Yapps\n") - self.write("import sys, re\n") - self.write("from yapps import runtime\n") - self.write("\n") - self.write("class ", self.name, "Scanner(runtime.Scanner):\n") - self.write(" patterns = [\n") - for p in self.terminals: - self.write(" (%s, re.compile(%s)),\n" % ( - repr(p), repr(self.tokens[p]))) - self.write(" ]\n") - self.write(" def __init__(self, str,*args,**kw):\n") - self.write(" runtime.Scanner.__init__(self,None,%s,str,*args,**kw)\n" % - self.repr_ignore()) - self.write("\n") - - self.write("class ", self.name, "(runtime.Parser):\n") - self.write(INDENT, "Context = runtime.Context\n") - for r in self.goals: - self.write(INDENT, "def ", r, "(self") - if self.params[r]: self.write(", ", self.params[r]) - self.write(", _parent=None):\n") - self.write(INDENT+INDENT, "_context = self.Context(_parent, self._scanner, %s, [%s])\n" % - (repr(r), self.params.get(r, ''))) - self.rules[r].output(self, INDENT+INDENT) - self.write("\n") - - self.write("\n") - self.write("def parse(rule, text):\n") - self.write(" P = ", self.name, "(", self.name, "Scanner(text))\n") - self.write(" return runtime.wrap_error_reporter(P, rule)\n") - self.write("\n") - if self.postparser is not None: - self.write("# End -- grammar generated by Yapps\n") - self.write(self.postparser) - else: - self.write("if __name__ == '__main__':\n") - self.write(INDENT, "from sys import argv, stdin\n") - self.write(INDENT, "if len(argv) >= 2:\n") - self.write(INDENT*2, "if len(argv) >= 3:\n") - self.write(INDENT*3, "f = open(argv[2],'r')\n") - self.write(INDENT*2, "else:\n") - self.write(INDENT*3, "f = stdin\n") - self.write(INDENT*2, "print parse(argv[1], f.read())\n") - self.write(INDENT, "else: print >>sys.stderr, 'Args: <rule> [<filename>]'\n") - self.write("# End -- grammar generated by Yapps\n") - -###################################################################### -class Node: - """This is the base class for all components of a grammar.""" - def __init__(self, rule): - self.rule = rule # name of the rule containing this node - self.first = [] - self.follow = [] - self.accepts_epsilon = 0 - - def setup(self, gen): - # Setup will change accepts_epsilon, - # sometimes from 0 to 1 but never 1 to 0. - # It will take a finite number of steps to set things up - pass - - def used(self, vars): - "Return two lists: one of vars used, and the other of vars assigned" - return vars, [] - - def get_children(self): - "Return a list of sub-nodes" - return [] - - def __repr__(self): - return str(self) - - def update(self, gen): - if self.accepts_epsilon: - gen.add_to(self.first, self.follow) - - def output(self, gen, indent): - "Write out code to _gen_ with _indent_:string indentation" - gen.write(indent, "assert 0 # Invalid parser node\n") - -class Terminal(Node): - """This class stores terminal nodes, which are tokens.""" - def __init__(self, rule, token): - Node.__init__(self, rule) - self.token = token - self.accepts_epsilon = 0 - - def __str__(self): - return self.token - - def update(self, gen): - Node.update(self, gen) - if self.first != [self.token]: - self.first = [self.token] - gen.changed() - - def output(self, gen, indent): - gen.write(indent) - if re.match('[a-zA-Z_][a-zA-Z_0-9]*$', self.token): - gen.write(self.token, " = ") - gen.write("self._scan(%s, context=_context)\n" % repr(self.token)) - -class Eval(Node): - """This class stores evaluation nodes, from {{ ... }} clauses.""" - def __init__(self, rule, expr): - Node.__init__(self, rule) - self.expr = expr - - def setup(self, gen): - Node.setup(self, gen) - if not self.accepts_epsilon: - self.accepts_epsilon = 1 - gen.changed() - - def __str__(self): - return '{{ %s }}' % self.expr.strip() - - def output(self, gen, indent): - gen.write(indent, self.expr.strip(), '\n') - -class NonTerminal(Node): - """This class stores nonterminal nodes, which are rules with arguments.""" - def __init__(self, rule, name, args): - Node.__init__(self, rule) - self.name = name - self.args = args - - def setup(self, gen): - Node.setup(self, gen) - try: - self.target = gen.rules[self.name] - if self.accepts_epsilon != self.target.accepts_epsilon: - self.accepts_epsilon = self.target.accepts_epsilon - gen.changed() - except KeyError: # Oops, it's nonexistent - print >>sys.stderr, 'Error: no rule <%s>' % self.name - self.target = self - - def __str__(self): - return '%s' % self.name - - def update(self, gen): - Node.update(self, gen) - gen.equate(self.first, self.target.first) - gen.equate(self.follow, self.target.follow) - - def output(self, gen, indent): - gen.write(indent) - gen.write(self.name, " = ") - args = self.args - if args: args += ', ' - args += '_context' - gen.write("self.", self.name, "(", args, ")\n") - -class Sequence(Node): - """This class stores a sequence of nodes (A B C ...)""" - def __init__(self, rule, *children): - Node.__init__(self, rule) - self.children = children - - def setup(self, gen): - Node.setup(self, gen) - for c in self.children: c.setup(gen) - - if not self.accepts_epsilon: - # If it's not already accepting epsilon, it might now do so. - for c in self.children: - # any non-epsilon means all is non-epsilon - if not c.accepts_epsilon: break - else: - self.accepts_epsilon = 1 - gen.changed() - - def get_children(self): - return self.children - - def __str__(self): - return '( %s )' % ' '.join(map(str, self.children)) - - def update(self, gen): - Node.update(self, gen) - for g in self.children: - g.update(gen) - - empty = 1 - for g_i in range(len(self.children)): - g = self.children[g_i] - - if empty: gen.add_to(self.first, g.first) - if not g.accepts_epsilon: empty = 0 - - if g_i == len(self.children)-1: - next = self.follow - else: - next = self.children[1+g_i].first - gen.add_to(g.follow, next) - - if self.children: - gen.add_to(self.follow, self.children[-1].follow) - - def output(self, gen, indent): - if self.children: - for c in self.children: - c.output(gen, indent) - else: - # Placeholder for empty sequences, just in case - gen.write(indent, 'pass\n') - -class Choice(Node): - """This class stores a choice between nodes (A | B | C | ...)""" - def __init__(self, rule, *children): - Node.__init__(self, rule) - self.children = children - - def setup(self, gen): - Node.setup(self, gen) - for c in self.children: c.setup(gen) - - if not self.accepts_epsilon: - for c in self.children: - if c.accepts_epsilon: - self.accepts_epsilon = 1 - gen.changed() - - def get_children(self): - return self.children - - def __str__(self): - return '( %s )' % ' | '.join(map(str, self.children)) - - def update(self, gen): - Node.update(self, gen) - for g in self.children: - g.update(gen) - - for g in self.children: - gen.add_to(self.first, g.first) - gen.add_to(self.follow, g.follow) - for g in self.children: - gen.add_to(g.follow, self.follow) - if self.accepts_epsilon: - gen.add_to(self.first, self.follow) - - def output(self, gen, indent): - test = "if" - gen.write(indent, "_token = ", gen.peek_call(self.first), "\n") - tokens_seen = [] - tokens_unseen = self.first[:] - if gen.has_option('context-insensitive-scanner'): - # Context insensitive scanners can return ANY token, - # not only the ones in first. - tokens_unseen = gen.non_ignored_tokens() - for c in self.children: - testset = c.first[:] - removed = [] - for x in testset: - if x in tokens_seen: - testset.remove(x) - removed.append(x) - if x in tokens_unseen: tokens_unseen.remove(x) - tokens_seen = tokens_seen + testset - if removed: - if not testset: - print >>sys.stderr, 'Error in rule', self.rule+':' - else: - print >>sys.stderr, 'Warning in rule', self.rule+':' - print >>sys.stderr, ' *', self - print >>sys.stderr, ' * These tokens could be matched by more than one clause:' - print >>sys.stderr, ' *', ' '.join(removed) - - if testset: - if not tokens_unseen: # context sensitive scanners only! - if test == 'if': - # if it's the first AND last test, then - # we can simply put the code without an if/else - c.output(gen, indent) - else: - gen.write(indent, "else:") - t = gen.in_test('', [], testset) - if len(t) < 70-len(indent): - gen.write(' #', t) - gen.write("\n") - c.output(gen, indent+INDENT) - else: - gen.write(indent, test, " ", - gen.in_test('_token', tokens_unseen, testset), - ":\n") - c.output(gen, indent+INDENT) - test = "elif" - - if tokens_unseen: - gen.write(indent, "else:\n") - gen.write(indent, INDENT, "raise runtime.SyntaxError(_token[0], ") - gen.write("'Could not match ", self.rule, "')\n") - -class Wrapper(Node): - """This is a base class for nodes that modify a single child.""" - def __init__(self, rule, child): - Node.__init__(self, rule) - self.child = child - - def setup(self, gen): - Node.setup(self, gen) - self.child.setup(gen) - - def get_children(self): - return [self.child] - - def update(self, gen): - Node.update(self, gen) - self.child.update(gen) - gen.add_to(self.first, self.child.first) - gen.equate(self.follow, self.child.follow) - -class Option(Wrapper): - """This class represents an optional clause of the form [A]""" - def setup(self, gen): - Wrapper.setup(self, gen) - if not self.accepts_epsilon: - self.accepts_epsilon = 1 - gen.changed() - - def __str__(self): - return '[ %s ]' % str(self.child) - - def output(self, gen, indent): - if self.child.accepts_epsilon: - print >>sys.stderr, 'Warning in rule', self.rule+': contents may be empty.' - gen.write(indent, "if %s:\n" % - gen.peek_test(self.first, self.child.first)) - self.child.output(gen, indent+INDENT) - - if gen.has_option('context-insensitive-scanner'): - gen.write(indent, "if %s:\n" % - gen.not_peek_test(gen.non_ignored_tokens(), self.follow)) - gen.write(indent+INDENT, "raise runtime.SyntaxError(pos=self._scanner.get_pos(), context=_context, msg='Need one of ' + ', '.join(%s))\n" % - repr(self.first)) - - -class Plus(Wrapper): - """This class represents a 1-or-more repetition clause of the form A+""" - def setup(self, gen): - Wrapper.setup(self, gen) - if self.accepts_epsilon != self.child.accepts_epsilon: - self.accepts_epsilon = self.child.accepts_epsilon - gen.changed() - - def __str__(self): - return '%s+' % str(self.child) - - def update(self, gen): - Wrapper.update(self, gen) - gen.add_to(self.child.follow, self.child.first) - - def output(self, gen, indent): - if self.child.accepts_epsilon: - print >>sys.stderr, 'Warning in rule', self.rule+':' - print >>sys.stderr, ' * The repeated pattern could be empty. The resulting parser may not work properly.' - gen.write(indent, "while 1:\n") - self.child.output(gen, indent+INDENT) - union = self.first[:] - gen.add_to(union, self.follow) - gen.write(indent+INDENT, "if %s: break\n" % - gen.not_peek_test(union, self.child.first)) - - if gen.has_option('context-insensitive-scanner'): - gen.write(indent, "if %s:\n" % - gen.not_peek_test(gen.non_ignored_tokens(), self.follow)) - gen.write(indent+INDENT, "raise runtime.SyntaxError(pos=self._scanner.get_pos(), context=_context, msg='Need one of ' + ', '.join(%s))\n" % - repr(self.first)) - - -class Star(Wrapper): - """This class represents a 0-or-more repetition clause of the form A*""" - def setup(self, gen): - Wrapper.setup(self, gen) - if not self.accepts_epsilon: - self.accepts_epsilon = 1 - gen.changed() - - def __str__(self): - return '%s*' % str(self.child) - - def update(self, gen): - Wrapper.update(self, gen) - gen.add_to(self.child.follow, self.child.first) - - def output(self, gen, indent): - if self.child.accepts_epsilon: - print >>sys.stderr, 'Warning in rule', self.rule+':' - print >>sys.stderr, ' * The repeated pattern could be empty. The resulting parser probably will not work properly.' - gen.write(indent, "while %s:\n" % - gen.peek_test(self.follow, self.child.first)) - self.child.output(gen, indent+INDENT) - - # TODO: need to generate tests like this in lots of rules - if gen.has_option('context-insensitive-scanner'): - gen.write(indent, "if %s:\n" % - gen.not_peek_test(gen.non_ignored_tokens(), self.follow)) - gen.write(indent+INDENT, "raise runtime.SyntaxError(pos=self._scanner.get_pos(), context=_context, msg='Need one of ' + ', '.join(%s))\n" % - repr(self.first)) - diff --git a/yapps/runtime.py b/yapps/runtime.py deleted file mode 100644 index 5d9d1d6..0000000 --- a/yapps/runtime.py +++ /dev/null @@ -1,442 +0,0 @@ -# Yapps 2 Runtime, part of Yapps 2 - yet another python parser system -# Copyright 1999-2003 by Amit J. Patel <amitp@cs.stanford.edu> -# Enhancements copyright 2003-2004 by Matthias Urlichs <smurf@debian.org> -# -# This version of the Yapps 2 Runtime can be distributed under the -# terms of the MIT open source license, either found in the LICENSE file -# included with the Yapps distribution -# <http://theory.stanford.edu/~amitp/yapps/> or at -# <http://www.opensource.org/licenses/mit-license.php> -# - -"""Run time libraries needed to run parsers generated by Yapps. - -This module defines parse-time exception classes, a scanner class, a -base class for parsers produced by Yapps, and a context class that -keeps track of the parse stack. - -""" - -import sys, re - -MIN_WINDOW=4096 -# File lookup window - -class SyntaxError(Exception): - """When we run into an unexpected token, this is the exception to use""" - def __init__(self, pos=None, msg="Bad Token", context=None): - Exception.__init__(self) - self.pos = pos - self.msg = msg - self.context = context - - def __str__(self): - if not self.pos: return 'SyntaxError' - else: return 'SyntaxError@%s(%s)' % (repr(self.pos), self.msg) - -class NoMoreTokens(Exception): - """Another exception object, for when we run out of tokens""" - pass - -class Token(object): - """Yapps token. - - This is a container for a scanned token. - """ - - def __init__(self, type,value, pos=None): - """Initialize a token.""" - self.type = type - self.value = value - self.pos = pos - - def __repr__(self): - output = '<%s: %s' % (self.type, repr(self.value)) - if self.pos: - output += " @ " - if self.pos[0]: - output += "%s:" % self.pos[0] - if self.pos[1]: - output += "%d" % self.pos[1] - if self.pos[2] is not None: - output += ".%d" % self.pos[2] - output += ">" - return output - -in_name=0 -class Scanner(object): - """Yapps scanner. - - The Yapps scanner can work in context sensitive or context - insensitive modes. The token(i) method is used to retrieve the - i-th token. It takes a restrict set that limits the set of tokens - it is allowed to return. In context sensitive mode, this restrict - set guides the scanner. In context insensitive mode, there is no - restriction (the set is always the full set of tokens). - - """ - - def __init__(self, patterns, ignore, input="", - file=None,filename=None,stacked=False): - """Initialize the scanner. - - Parameters: - patterns : [(terminal, uncompiled regex), ...] or None - ignore : {terminal:None, ...} - input : string - - If patterns is None, we assume that the subclass has - defined self.patterns : [(terminal, compiled regex), ...]. - Note that the patterns parameter expects uncompiled regexes, - whereas the self.patterns field expects compiled regexes. - - The 'ignore' value is either None or a callable, which is called - with the scanner and the to-be-ignored match object; this can - be used for include file or comment handling. - """ - - if not filename: - global in_name - filename="<f.%d>" % in_name - in_name += 1 - - self.input = input - self.ignore = ignore - self.file = file - self.filename = filename - self.pos = 0 - self.del_pos = 0 # skipped - self.line = 1 - self.del_line = 0 # skipped - self.col = 0 - self.tokens = [] - self.stack = None - self.stacked = stacked - - self.last_read_token = None - self.last_token = None - self.last_types = None - - if patterns is not None: - # Compile the regex strings into regex objects - self.patterns = [] - for terminal, regex in patterns: - self.patterns.append( (terminal, re.compile(regex)) ) - - def stack_input(self, input="", file=None, filename=None): - """Temporarily parse from a second file.""" - - # Already reading from somewhere else: Go on top of that, please. - if self.stack: - # autogenerate a recursion-level-identifying filename - if not filename: - filename = 1 - else: - try: - filename += 1 - except TypeError: - pass - # now pass off to the include file - self.stack.stack_input(input,file,filename) - else: - - try: - filename += 0 - except TypeError: - pass - else: - filename = "<str_%d>" % filename - -# self.stack = object.__new__(self.__class__) -# Scanner.__init__(self.stack,self.patterns,self.ignore,input,file,filename, stacked=True) - - # Note that the pattern+ignore are added by the generated - # scanner code - self.stack = self.__class__(input,file,filename, stacked=True) - - def get_pos(self): - """Return a file/line/char tuple.""" - if self.stack: return self.stack.get_pos() - - return (self.filename, self.line+self.del_line, self.col) - -# def __repr__(self): -# """Print the last few tokens that have been scanned in""" -# output = '' -# for t in self.tokens: -# output += '%s\n' % (repr(t),) -# return output - - def print_line_with_pointer(self, pos, length=0, out=sys.stderr): - """Print the line of 'text' that includes position 'p', - along with a second line with a single caret (^) at position p""" - - file,line,p = pos - if file != self.filename: - if self.stack: return self.stack.print_line_with_pointer(pos,length=length,out=out) - print >>out, "(%s: not in input buffer)" % file - return - - text = self.input - p += length-1 # starts at pos 1 - - origline=line - line -= self.del_line - spos=0 - if line > 0: - while 1: - line = line - 1 - try: - cr = text.index("\n",spos) - except ValueError: - if line: - text = "" - break - if line == 0: - text = text[spos:cr] - break - spos = cr+1 - else: - print >>out, "(%s:%d not in input buffer)" % (file,origline) - return - - # Now try printing part of the line - text = text[max(p-80, 0):p+80] - p = p - max(p-80, 0) - - # Strip to the left - i = text[:p].rfind('\n') - j = text[:p].rfind('\r') - if i < 0 or (0 <= j < i): i = j - if 0 <= i < p: - p = p - i - 1 - text = text[i+1:] - - # Strip to the right - i = text.find('\n', p) - j = text.find('\r', p) - if i < 0 or (0 <= j < i): i = j - if i >= 0: - text = text[:i] - - # Now shorten the text - while len(text) > 70 and p > 60: - # Cut off 10 chars - text = "..." + text[10:] - p = p - 7 - - # Now print the string, along with an indicator - print >>out, '> ',text - print >>out, '> ',' '*p + '^' - - def grab_input(self): - """Get more input if possible.""" - if not self.file: return - if len(self.input) - self.pos >= MIN_WINDOW: return - - data = self.file.read(MIN_WINDOW) - if data is None or data == "": - self.file = None - - # Drop bytes from the start, if necessary. - if self.pos > 2*MIN_WINDOW: - self.del_pos += MIN_WINDOW - self.del_line += self.input[:MIN_WINDOW].count("\n") - self.pos -= MIN_WINDOW - self.input = self.input[MIN_WINDOW:] + data - else: - self.input = self.input + data - - def getchar(self): - """Return the next character.""" - self.grab_input() - - c = self.input[self.pos] - self.pos += 1 - return c - - def token(self, restrict, context=None): - """Scan for another token.""" - - while 1: - if self.stack: - try: - return self.stack.token(restrict, context) - except StopIteration: - self.stack = None - - # Keep looking for a token, ignoring any in self.ignore - self.grab_input() - - # special handling for end-of-file - if self.stacked and self.pos==len(self.input): - raise StopIteration - - # Search the patterns for the longest match, with earlier - # tokens in the list having preference - best_match = -1 - best_pat = '(error)' - best_m = None - for p, regexp in self.patterns: - # First check to see if we're ignoring this token - if restrict and p not in restrict and p not in self.ignore: - continue - m = regexp.match(self.input, self.pos) - if m and m.end()-m.start() > best_match: - # We got a match that's better than the previous one - best_pat = p - best_match = m.end()-m.start() - best_m = m - - # If we didn't find anything, raise an error - if best_pat == '(error)' and best_match < 0: - msg = 'Bad Token' - if restrict: - msg = 'Trying to find one of '+', '.join(restrict) - raise SyntaxError(self.get_pos(), msg, context=context) - - ignore = best_pat in self.ignore - value = self.input[self.pos:self.pos+best_match] - if not ignore: - tok=Token(type=best_pat, value=value, pos=self.get_pos()) - - self.pos += best_match - - npos = value.rfind("\n") - if npos > -1: - self.col = best_match-npos - self.line += value.count("\n") - else: - self.col += best_match - - # If we found something that isn't to be ignored, return it - if not ignore: - if len(self.tokens) >= 10: - del self.tokens[0] - self.tokens.append(tok) - self.last_read_token = tok - # print repr(tok) - return tok - else: - ignore = self.ignore[best_pat] - if ignore: - ignore(self, best_m) - - def peek(self, *types, **kw): - """Returns the token type for lookahead; if there are any args - then the list of args is the set of token types to allow""" - context = kw.get("context",None) - if self.last_token is None: - self.last_types = types - self.last_token = self.token(types,context) - elif self.last_types: - for t in types: - if t not in self.last_types: - raise NotImplementedError("Unimplemented: restriction set changed") - return self.last_token.type - - def scan(self, type, **kw): - """Returns the matched text, and moves to the next token""" - context = kw.get("context",None) - - if self.last_token is None: - tok = self.token([type],context) - else: - if self.last_types and type not in self.last_types: - raise NotImplementedError("Unimplemented: restriction set changed") - - tok = self.last_token - self.last_token = None - if tok.type != type: - if not self.last_types: self.last_types=[] - raise SyntaxError(tok.pos, 'Trying to find '+type+': '+ ', '.join(self.last_types)+", got "+tok.type, context=context) - return tok.value - -class Parser(object): - """Base class for Yapps-generated parsers. - - """ - - def __init__(self, scanner): - self._scanner = scanner - - def _stack(self, input="",file=None,filename=None): - """Temporarily read from someplace else""" - self._scanner.stack_input(input,file,filename) - self._tok = None - - def _peek(self, *types, **kw): - """Returns the token type for lookahead; if there are any args - then the list of args is the set of token types to allow""" - return self._scanner.peek(*types, **kw) - - def _scan(self, type, **kw): - """Returns the matched text, and moves to the next token""" - return self._scanner.scan(type, **kw) - -class Context(object): - """Class to represent the parser's call stack. - - Every rule creates a Context that links to its parent rule. The - contexts can be used for debugging. - - """ - - def __init__(self, parent, scanner, rule, args=()): - """Create a new context. - - Args: - parent: Context object or None - scanner: Scanner object - rule: string (name of the rule) - args: tuple listing parameters to the rule - - """ - self.parent = parent - self.scanner = scanner - self.rule = rule - self.args = args - while scanner.stack: scanner = scanner.stack - self.token = scanner.last_read_token - - def __str__(self): - output = '' - if self.parent: output = str(self.parent) + ' > ' - output += self.rule - return output - -def print_error(err, scanner, max_ctx=None): - """Print error messages, the parser stack, and the input text -- for human-readable error messages.""" - # NOTE: this function assumes 80 columns :-( - # Figure out the line number - pos = err.pos - if not pos: - pos = scanner.get_pos() - - file_name, line_number, column_number = pos - print >>sys.stderr, '%s:%d:%d: %s' % (file_name, line_number, column_number, err.msg) - - scanner.print_line_with_pointer(pos) - - context = err.context - token = None - while context: - print >>sys.stderr, 'while parsing %s%s:' % (context.rule, tuple(context.args)) - if context.token: - token = context.token - if token: - scanner.print_line_with_pointer(token.pos, length=len(token.value)) - context = context.parent - if max_ctx: - max_ctx = max_ctx-1 - if not max_ctx: - break - -def wrap_error_reporter(parser, rule, *args,**kw): - try: - return getattr(parser, rule)(*args,**kw) - except SyntaxError, e: - print_error(e, parser._scanner) - except NoMoreTokens: - print >>sys.stderr, 'Could not complete parsing; stopped around here:' - print >>sys.stderr, parser._scanner |