#!/usr/bin/env python

# -*- coding: utf-8 -*-

""" java2python.lang.base -> lexer and parser support classes. """

##

# This module provides the following:

#

# * `Tokens`

#

# This class is used to create the single `token` instance in this

# module. It is used to map between parser tokens and their ids and

# vice-versa.

#

# * `TreeAdaptor`

#

# This class is used by `java2python.compiler.tool`, where the

# `buildAST` function associates an instance of it to a parser. The

# `TreeAdaptor` class creates `LocalTree` instances.

#

# * `LocalTree`

#

# This class provides a slew of extra utility methods that are useful

# when inspecting and printing tree nodes.

#

##

# ANTLR notes:

#

# recognizers: lexer, parser, treeparser

# streams: string, file name, file handle

#

# Parsers use TokenStreams (CommonTokenStream or TokenRewriteStream)

#

# Tree parsers use TreeNodeStream (CommonTreeNodeStream)

#

# Lexers emit Token objects (buffered in TokenStream objects)

#

# Parsers build trees if their output is AST.

#

# token types: CommonToken and ClassicToken. Our tree adaptor

# creates LocalTree instances instead.

#

# Tree (CommonTree) wraps Token objects. We provide extra functionality via

# the LocalTree class.

#

# TreeAdaptor (CommonTreeAdaptor) is used by the parser to create

# Tree objects. Our adaptor, TreeAdaptor, creates the LocalTree

# instances.

#

from cStringIO import StringIO

from antlr3 import ANTLRStringStream as StringStream, CommonTokenStream as TokenStream

from antlr3.tree import CommonTreeAdaptor, CommonTree

from java2python.lib import colors

class Tokens(object):

""" Tokens -> simplifies token id-name and name-id mapping. """

def __init__(self):

self.cache, self.parserModule = {}, None

def __getattr__(self, name):

""" tokenname -> tokenvalue """

return getattr(self.module, name)

@property

def commentTypes(self):

""" Well-known comment types. """

mod = self.module

return (mod.COMMENT, mod.LINE_COMMENT, mod.JAVADOC_COMMENT, )

@property

def map(self):

""" (tokentype, tokenname) mapping as a dictionary """

cache, module = self.cache, self.module

if cache:

return cache

mapping = [(getattr(module, k, None), k) for k in module.tokenNames]

mapping = [(k, v) for k, v in mapping if k is not None]

cache.update(mapping)

return cache

@property

def methodTypes(self):

""" Well-known method types. """

mod = self.module

return (mod.VOID_METHOD_DECL, mod.FUNCTION_METHOD_DECL, )

@property

def module(self):

""" Provides lazy import to the parser module. """

module = self.parserModule

if module:

return module

import java2python.lang.JavaParser as module

self.parserModule = module

return module

@staticmethod

def title(name):

""" Returns a nice title given a token type name. """

return ''.join(part.title() for part in name.split('_'))

## sometimes you really do only need one.

tokens = Tokens()

class TreeAdaptor(CommonTreeAdaptor):

""" TreeAdaptor -> defered tree node creator (for parsers) """

def __init__(self, lexer, parser):

# CommonTreeAdaptor doesn't need to be __init__'ed

self.lexer, self.parser = lexer, parser

def createWithPayload(self, payload):

""" Returns a new tree for the calling parser. """

return LocalTree(payload, self.lexer, self.parser)

class LocalTree(CommonTree):

""" LocalTree -> like CommonTree, but with much more stuff

"""

colorTypeMap = {

'CLASS' : colors.green,

'JAVA_SOURCE' : colors.green,

'VOID_METHOD_DECL' : colors.green,

'IDENT' : colors.yellow,

'TYPE' : colors.magenta,

'EXPR' : colors.blue,

'TRUE' : colors.yellow,

'FALSE' : colors.yellow,

'NULL' : colors.yellow,

}

def __init__(self, payload, lexer=None, parser=None):

super(LocalTree, self).__init__(payload)

self.lexer, self.parser = lexer, parser

def childrenOfType(self, type):

""" Returns a generator yielding children of this tree of the given type. """

return (c for c in self.children if c.type==type)

def colorType(self, tokenType):

""" Returns a color suitable for the given token type. """

return self.colorTypeMap.get(tokenType, colors.white)(tokenType)

def colorText(self, tokenType, tokenText):

""" Returns a colorized string from the given token type and text. """

return self.colorTypeMap.get(tokenType, colors.white)(tokenText)

def colorComments(self, token):

""" Formats, colors, and returns the comment text from the given token. """

ttyp = tokens.map.get(token.type)

text = token.text.replace('\n', '\\n').replace('\r', '\\r').replace('\t', '\\t')

item = '{0} [{1}:{2}] {3}'.format(ttyp, token.start, token.stop, text)

yield colors.black(item)

def dump(self, fd, level=0):

""" Writes a debug representation of this tree to the given file. """

extras = lambda x, y:x and (x != y)

seen, nform = set(), '{0}{1}{2}{3}'

def innerDump(root, offset):

token, indent = root.token, ' ' * offset

start, stop = root.tokenStartIndex, root.tokenStopIndex

idxes, ttyp = '', tokens.map.get(token.type, '?')

line = token.line

if start and stop and start == stop:

idxes = 'start={}'.format(start)

elif start and stop:

idxes = 'start={}, stop={}'.format(start, stop)

if line:

idxes = 'line={}{}{}'.format(line, ', ' if idxes else '', idxes)

idxes = ' [{}]'.format(idxes) if idxes else ''

idxes = colors.black(idxes)

args = [indent, self.colorType(ttyp), '', idxes, '']

if extras(token.text, ttyp):

args[2] = ' ' + self.colorText(ttyp, token.text)

for com in self.selectComments(start, seen):

for line in self.colorComments(com):

print >> fd, '{0}{1}'.format(indent, line)

print >> fd, nform.format(*args)

for child in root.getChildren():

innerDump(child, offset+1)

for com in self.selectComments(root.tokenStopIndex, seen):

for line in self.colorComments(com):

print >> fd, '{0}{1}'.format(indent, line)

innerDump(self, level)

def dumps(self, level=0):

""" Dump this token to a string. """

fd = StringIO()

self.dump(fd, level)

return fd.getvalue()

def dupNode(self):

""" Called by the parser to create a duplicate of this tree. """

get = lambda v:getattr(self, v, None)

return LocalTree(self, get('lexer'), get('parser'))

def findChildren(self, pred=lambda c:True):

""" Depth-first search that yields nodes meeting the predicate. """

for child in self.children:

if pred(child):

yield child

for sub in child.findChildren(pred):

yield sub

def findChildrenOfType(self, type):

""" Depth-first search that yields nodes of the given type. """

return self.findChildren(lambda c:c.type==type)

def firstChild(self, default=None):

""" Returns the first child of this tree or the default. """

try:

return self.children[0]

except (IndexError, ):

return default

def firstChildOfType(self, type, default=None):

""" Returns the first child of this tree that matches the given type. """

for child in self.children:

if child.type == type:

return child

return default

@property

def isJavaSource(self):

""" True if this tree is the outer most type. """

return self.token.type == tokens.JAVA_SOURCE

@property

def parentType(self):

""" Returns the type of the parent tree. """

return self.parent.type

def parents(self, pred=lambda v:True):

""" Yield each parent in the family tree. """

while self:

if pred(self):

yield self

self = self.parent

@property

def parserTokens(self):

""" Returns the sequence of tokens used to create this tree. """

return self.parser.input.tokens[self.tokenStartIndex:self.tokenStopIndex]

def selectComments(self, stop, memo):

""" Returns the comment tokens for this tree up to the given index. """

pred = lambda k:k.type in tokens.commentTypes and k.index not in memo

ctoks = [t for t in self.parser.input.tokens[0:stop] if pred(t)]

memo.update(t.index for t in ctoks)

return ctoks

@property

def withinExpr(self):

""" True if this tree is contained within an expression. """

self = getattr(self.parent, 'parent', None) # skip first expr

while self:

if self.type in (tokens.EXPR, ):

return True

self = self.parent