""" @package antlr3.tree

@brief ANTLR3 runtime package, treewizard module

A utility module to create ASTs at runtime.

See <http://www.antlr.org/wiki/display/~admin/2007/07/02/Exploring+Concept+of+TreeWizard> for an overview. Note that the API of the Python implementation is slightly different.

"""

# begin[licence]

#

# [The "BSD licence"]

# Copyright (c) 2005-2008 Terence Parr

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from antlr3.constants import INVALID_TOKEN_TYPE

from antlr3.tokens import CommonToken

from antlr3.tree import CommonTree, CommonTreeAdaptor

def computeTokenTypes(tokenNames):

    """

    Compute a dict that is an inverted index of

    tokenNames (which maps int token types to names).

    """

    if tokenNames is None:

        return {}

    return dict((name, type) for type, name in enumerate(tokenNames))

## token types for pattern parser

EOF = -1

BEGIN = 1

END = 2

ID = 3

ARG = 4

PERCENT = 5

COLON = 6

DOT = 7

class TreePatternLexer(object):

    def __init__(self, pattern):

        ## The tree pattern to lex like "(A B C)"

        self.pattern = pattern

	## Index into input string

        self.p = -1

	## Current char

        self.c = None

	## How long is the pattern in char?

        self.n = len(pattern)

	## Set when token type is ID or ARG

        self.sval = None

        self.error = False

        self.consume()

    __idStartChar = frozenset(

        'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_'

        )

    __idChar = __idStartChar | frozenset('0123456789')

    def nextToken(self):

        self.sval = ""

        while self.c != EOF:

            if self.c in (' ', '\n', '\r', '\t'):

                self.consume()

                continue

            if self.c in self.__idStartChar:

                self.sval += self.c

                self.consume()

                while self.c in self.__idChar:

                    self.sval += self.c

                    self.consume()

                return ID

            if self.c == '(':

                self.consume()

                return BEGIN

            if self.c == ')':

                self.consume()

                return END

            if self.c == '%':

                self.consume()

                return PERCENT

            if self.c == ':':

                self.consume()

                return COLON

            if self.c == '.':

                self.consume()

                return DOT

            if self.c == '[': # grab [x] as a string, returning x

                self.consume()

                while self.c != ']':

                    if self.c == '\\':

                        self.consume()

                        if self.c != ']':

                            self.sval += '\\'

                        self.sval += self.c

                    else:

                        self.sval += self.c

                    self.consume()

                self.consume()

                return ARG

            self.consume()

            self.error = True

            return EOF

        return EOF

    def consume(self):

        self.p += 1

        if self.p >= self.n:

            self.c = EOF

        else:

            self.c = self.pattern[self.p]

class TreePatternParser(object):

    def __init__(self, tokenizer, wizard, adaptor):

        self.tokenizer = tokenizer

        self.wizard = wizard

        self.adaptor = adaptor

        self.ttype = tokenizer.nextToken() # kickstart

    def pattern(self):

        if self.ttype == BEGIN:

            return self.parseTree()

        elif self.ttype == ID:

            node = self.parseNode()

            if self.ttype == EOF:

                return node

            return None # extra junk on end

        return None

    def parseTree(self):

        if self.ttype != BEGIN:

            return None

        self.ttype = self.tokenizer.nextToken()

        root = self.parseNode()

        if root is None:

            return None

        while self.ttype in (BEGIN, ID, PERCENT, DOT):

            if self.ttype == BEGIN:

                subtree = self.parseTree()

                self.adaptor.addChild(root, subtree)

            else:

                child = self.parseNode()

                if child is None:

                    return None

                self.adaptor.addChild(root, child)

        if self.ttype != END:

            return None

        self.ttype = self.tokenizer.nextToken()

        return root

    def parseNode(self):

        # "%label:" prefix

        label = None

        if self.ttype == PERCENT:

            self.ttype = self.tokenizer.nextToken()

            if self.ttype != ID:

                return None

            label = self.tokenizer.sval

            self.ttype = self.tokenizer.nextToken()

            if self.ttype != COLON:

                return None

            self.ttype = self.tokenizer.nextToken() # move to ID following colon

        # Wildcard?

        if self.ttype == DOT:

            self.ttype = self.tokenizer.nextToken()

            wildcardPayload = CommonToken(0, ".")

            node = WildcardTreePattern(wildcardPayload)

            if label is not None:

                node.label = label

            return node

        # "ID" or "ID[arg]"

        if self.ttype != ID:

            return None

        tokenName = self.tokenizer.sval

        self.ttype = self.tokenizer.nextToken()

        if tokenName == "nil":

            return self.adaptor.nil()

        text = tokenName

        # check for arg

        arg = None

        if self.ttype == ARG:

            arg = self.tokenizer.sval

            text = arg

            self.ttype = self.tokenizer.nextToken()

        # create node

        treeNodeType = self.wizard.getTokenType(tokenName)

        if treeNodeType == INVALID_TOKEN_TYPE:

            return None

        node = self.adaptor.createFromType(treeNodeType, text)

        if label is not None and isinstance(node, TreePattern):

            node.label = label

        if arg is not None and isinstance(node, TreePattern):

            node.hasTextArg = True

        return node

class TreePattern(CommonTree):

    """

    When using %label:TOKENNAME in a tree for parse(), we must

    track the label.

    """

    def __init__(self, payload):

        CommonTree.__init__(self, payload)

        self.label = None

        self.hasTextArg = None

    def toString(self):

        if self.label is not None:

            return '%' + self.label + ':' + CommonTree.toString(self)

        else:

            return CommonTree.toString(self)

class WildcardTreePattern(TreePattern):

    pass

class TreePatternTreeAdaptor(CommonTreeAdaptor):

    """This adaptor creates TreePattern objects for use during scan()"""

    def createWithPayload(self, payload):

        return TreePattern(payload)

class TreeWizard(object):

    """

    Build and navigate trees with this object.  Must know about the names

    of tokens so you have to pass in a map or array of token names (from which

    this class can build the map).  I.e., Token DECL means nothing unless the

    class can translate it to a token type.

    In order to create nodes and navigate, this class needs a TreeAdaptor.

    This class can build a token type -> node index for repeated use or for

    iterating over the various nodes with a particular type.

    This class works in conjunction with the TreeAdaptor rather than moving

    all this functionality into the adaptor.  An adaptor helps build and

    navigate trees using methods.  This class helps you do it with string

    patterns like "(A B C)".  You can create a tree from that pattern or

    match subtrees against it.

    """

    def __init__(self, adaptor=None, tokenNames=None, typeMap=None):

        self.adaptor = adaptor

        if typeMap is None:

            self.tokenNameToTypeMap = computeTokenTypes(tokenNames)

        else:

            if tokenNames is not None:

                raise ValueError("Can't have both tokenNames and typeMap")

            self.tokenNameToTypeMap = typeMap

    def getTokenType(self, tokenName):

        """Using the map of token names to token types, return the type."""

        try:

            return self.tokenNameToTypeMap[tokenName]

        except KeyError:

            return INVALID_TOKEN_TYPE

    def create(self, pattern):

        """

        Create a tree or node from the indicated tree pattern that closely

        follows ANTLR tree grammar tree element syntax:

        (root child1 ... child2).

        You can also just pass in a node: ID

        Any node can have a text argument: ID[foo]

        (notice there are no quotes around foo--it's clear it's a string).

        nil is a special name meaning "give me a nil node".  Useful for

        making lists: (nil A B C) is a list of A B C.

        """

        tokenizer = TreePatternLexer(pattern)

        parser = TreePatternParser(tokenizer, self, self.adaptor)

        return parser.pattern()

    def index(self, tree):

        """Walk the entire tree and make a node name to nodes mapping.

        For now, use recursion but later nonrecursive version may be

        more efficient.  Returns a dict int -> list where the list is

        of your AST node type.  The int is the token type of the node.

        """

        m = {}

        self._index(tree, m)

        return m

    def _index(self, t, m):

        """Do the work for index"""

        if t is None:

            return

        ttype = self.adaptor.getType(t)

        elements = m.get(ttype)

        if elements is None:

            m[ttype] = elements = []

        elements.append(t)

        for i in range(self.adaptor.getChildCount(t)):

            child = self.adaptor.getChild(t, i)

            self._index(child, m)

    def find(self, tree, what):

        """Return a list of matching token.

        what may either be an integer specifzing the token type to find or

        a string with a pattern that must be matched.

        """

        if isinstance(what, (int, long)):

            return self._findTokenType(tree, what)

        elif isinstance(what, basestring):

            return self._findPattern(tree, what)

        else:

            raise TypeError("'what' must be string or integer")

    def _findTokenType(self, t, ttype):

        """Return a List of tree nodes with token type ttype"""

        nodes = []

        def visitor(tree, parent, childIndex, labels):

            nodes.append(tree)

        self.visit(t, ttype, visitor)

        return nodes

    def _findPattern(self, t, pattern):

        """Return a List of subtrees matching pattern."""

        subtrees = []

        # Create a TreePattern from the pattern

        tokenizer = TreePatternLexer(pattern)

        parser = TreePatternParser(tokenizer, self, TreePatternTreeAdaptor())

        tpattern = parser.pattern()

        # don't allow invalid patterns

        if (tpattern is None or tpattern.isNil()

            or isinstance(tpattern, WildcardTreePattern)):

            return None

        rootTokenType = tpattern.getType()

        def visitor(tree, parent, childIndex, label):

            if self._parse(tree, tpattern, None):

                subtrees.append(tree)

        self.visit(t, rootTokenType, visitor)

        return subtrees

    def visit(self, tree, what, visitor):

        """Visit every node in tree matching what, invoking the visitor.

        If what is a string, it is parsed as a pattern and only matching

        subtrees will be visited.

        The implementation uses the root node of the pattern in combination

        with visit(t, ttype, visitor) so nil-rooted patterns are not allowed.

        Patterns with wildcard roots are also not allowed.

        If what is an integer, it is used as a token type and visit will match

        all nodes of that type (this is faster than the pattern match).

        The labels arg of the visitor action method is never set (it's None)

        since using a token type rather than a pattern doesn't let us set a

        label.

        """

        if isinstance(what, (int, long)):

            self._visitType(tree, None, 0, what, visitor)

        elif isinstance(what, basestring):

            self._visitPattern(tree, what, visitor)

        else:

            raise TypeError("'what' must be string or integer")

    def _visitType(self, t, parent, childIndex, ttype, visitor):

        """Do the recursive work for visit"""

        if t is None:

            return

        if self.adaptor.getType(t) == ttype:

            visitor(t, parent, childIndex, None)

        for i in range(self.adaptor.getChildCount(t)):

            child = self.adaptor.getChild(t, i)

            self._visitType(child, t, i, ttype, visitor)

    def _visitPattern(self, tree, pattern, visitor):

        """

        For all subtrees that match the pattern, execute the visit action.

        """

        # Create a TreePattern from the pattern

        tokenizer = TreePatternLexer(pattern)

        parser = TreePatternParser(tokenizer, self, TreePatternTreeAdaptor())

        tpattern = parser.pattern()

        # don't allow invalid patterns

        if (tpattern is None or tpattern.isNil()

            or isinstance(tpattern, WildcardTreePattern)):

            return

        rootTokenType = tpattern.getType()

        def rootvisitor(tree, parent, childIndex, labels):

            labels = {}

            if self._parse(tree, tpattern, labels):

                visitor(tree, parent, childIndex, labels)

        self.visit(tree, rootTokenType, rootvisitor)

    def parse(self, t, pattern, labels=None):

        """

        Given a pattern like (ASSIGN %lhs:ID %rhs:.) with optional labels

        on the various nodes and '.' (dot) as the node/subtree wildcard,

        return true if the pattern matches and fill the labels Map with

        the labels pointing at the appropriate nodes.  Return false if

        the pattern is malformed or the tree does not match.

        If a node specifies a text arg in pattern, then that must match

        for that node in t.

        """

        tokenizer = TreePatternLexer(pattern)

        parser = TreePatternParser(tokenizer, self, TreePatternTreeAdaptor())