pmacs3/parse.py

import re
import lex

MAX_MAX = 1024

class Rule(object):
    def __init__(self, *rules):
        self.rules = rules
    def match(self, tokens):
        if not tokens:
            return []
        return self._match(tokens)
    def _match(self, tokens):
        raise Exception("unimplemented")

class Any(Rule):
    def __init__(self):
        pass
    def _match(self, tokens):
        if tokens:
            return [1]
        else:
            return []

class Name(Rule):
    def __init__(self, name):
        self.name = name
    def _match(self, tokens):
        if tokens[0].name == self.name:
            return [1]
        else:
            return []
class Names(Rule):
    def __init__(self, names):
        self.names = names
    def _match(self, tokens):
        if token.name in self.names:
            return [1]
        else:
            return []

class String(Rule):
    def __init__(self, s):
        self.string = s
    def _match(self, tokens):
        if token.string == self.string:
            return [1]
        else:
            return []
class Strings(Rule):
    def __init__(self, ss):
        self.strings = ss
    def _match(self, tokens):
        if token.string in self.strings:
            return [1]
        else:
            return []
class Stringre(Rule):
    def __init__(self, r):
        self.regex = re.compile(r)
    def _match(self, tokens):
        if self.regex.match(token.string):
            return [1]
        else:
            return []

class Match(Rule):
    method = lex.Token.match
    def __init__(self, *args):
        self.args = args
    def match(self, tokens):
        if not tokens:
            return []
        elif self.method(tokens[0], *self.args):
            return [1]
        else:
            return []
class Matchs(Match):
    method = lex.Token.matchs
class Matchp(Match):
    method = lex.Token.matchp

class Fqmatch(Match):
    method = lex.Token.fqmatch
class Fqmatchs(Match):
    method = lex.Token.fqmatchs
class Fqmatchp(Match):
    method = lex.Token.fqmatchp

class And(Rule):
    def match(self, tokens):
        n = 0
        for r in self.rules:
            result = r.match(tokens[n:])
            if not result:
                return []
            n += result[0]
        return [n]
class Or(Rule):
    def match(self, tokens):
        for r in self.rules:
            result = r.match(tokens[n:])
            if result:
                return result
        return []

class Repeat(Rule):
    def __init__(self, rule, minimum, maximum):
        self.rule = rule
        self.minimum = minimum
        self.maximum = maximum
    def match(self, tokens):
        n = 0
        for i in range(0, self.minimum):
            result = self.rule.match(tokens[n:])
            if not result:
                return []
            n += result[0]
        for i in range(self.minimum, self.maximum):
            result = self.rule.match(tokens[n:])
            if not result:
                return [n]
            n += result[0]
        return [n]

class Optional(Repeat):
    def __init__(self, rule):
        self.rule    = rule
        self.minimum = 0
        self.maximum = 1
class Star(Repeat):
    def __init__(self, rule):
        self.rule    = rule
        self.minimum = 0
        self.maximum = MAX_MAX
class Plus(Repeat):
    def __init__(self, rule):
        self.rule    = rule
        self.minimum = 1
        self.maximum = MAX_MAX

class End(Rule):
    def __init__(self):
        pass
    def match(self, tokens):
        if tokens:
            return []
        else:
            return [0]