patchedast.py :  » Development » Rope » rope-0.9.2 » rope » refactor » Python Open Source

Home
Python Open Source
1.3.1.2 Python
2.Ajax
3.Aspect Oriented
4.Blog
5.Build
6.Business Application
7.Chart Report
8.Content Management Systems
9.Cryptographic
10.Database
11.Development
12.Editor
13.Email
14.ERP
15.Game 2D 3D
16.GIS
17.GUI
18.IDE
19.Installer
20.IRC
21.Issue Tracker
22.Language Interface
23.Log
24.Math
25.Media Sound Audio
26.Mobile
27.Network
28.Parser
29.PDF
30.Project Management
31.RSS
32.Search
33.Security
34.Template Engines
35.Test
36.UML
37.USB Serial
38.Web Frameworks
39.Web Server
40.Web Services
41.Web Unit
42.Wiki
43.Windows
44.XML
Python Open Source » Development » Rope 
Rope » rope 0.9.2 » rope » refactor » patchedast.py
import collections
import re
import warnings

from rope.base import ast,codeanalyze,exceptions


def get_patched_ast(source, sorted_children=False):
    """Adds ``region`` and ``sorted_children`` fields to nodes

    Adds ``sorted_children`` field only if `sorted_children` is True.

    """
    return patch_ast(ast.parse(source), source, sorted_children)


def patch_ast(node, source, sorted_children=False):
    """Patches the given node

    After calling, each node in `node` will have a new field named
    `region` that is a tuple containing the start and end offsets
    of the code that generated it.

    If `sorted_children` is true, a `sorted_children` field will
    be created for each node, too.  It is a list containing child
    nodes as well as whitespaces and comments that occur between
    them.

    """
    if hasattr(node, 'region'):
        return node
    walker = _PatchingASTWalker(source, children=sorted_children)
    ast.call_for_nodes(node, walker)
    return node


def node_region(patched_ast_node):
    """Get the region of a patched ast node"""
    return patched_ast_node.region


def write_ast(patched_ast_node):
    """Extract source form a patched AST node with `sorted_children` field

    If the node is patched with sorted_children turned off you can use
    `node_region` function for obtaining code using module source code.
    """
    result = []
    for child in patched_ast_node.sorted_children:
        if isinstance(child, ast.AST):
            result.append(write_ast(child))
        else:
            result.append(child)
    return ''.join(result)


class MismatchedTokenError(exceptions.RopeError):
    pass


class _PatchingASTWalker(object):

    def __init__(self, source, children=False):
        self.source = _Source(source)
        self.children = children
        self.lines = codeanalyze.SourceLinesAdapter(source)
        self.children_stack = []

    Number = object()
    String = object()

    def __call__(self, node):
        method = getattr(self, '_' + node.__class__.__name__, None)
        if method is not None:
            return method(node)
        # ???: Unknown node; what should we do here?
        warnings.warn('Unknown node type <%s>; please report!'
                      % node.__class__.__name__, RuntimeWarning)
        node.region = (self.source.offset, self.source.offset)
        if self.children:
            node.sorted_children = ast.get_children(node)

    def _handle(self, node, base_children, eat_parens=False, eat_spaces=False):
        if hasattr(node, 'region'):
            # ???: The same node was seen twice; what should we do?
            warnings.warn(
                'Node <%s> has been already patched; please report!' %
                node.__class__.__name__, RuntimeWarning)
            return
        base_children = collections.deque(base_children)
        self.children_stack.append(base_children)
        children = collections.deque()
        formats = []
        suspected_start = self.source.offset
        start = suspected_start
        first_token = True
        while base_children:
            child = base_children.popleft()
            if child is None:
                continue
            offset = self.source.offset
            if isinstance(child, ast.AST):
                ast.call_for_nodes(child, self)
                token_start = child.region[0]
            else:
                if child is self.String:
                    region = self.source.consume_string(
                        end=self._find_next_statement_start())
                elif child is self.Number:
                    region = self.source.consume_number()
                elif child == '!=':
                    # INFO: This has been added to handle deprecated ``<>``
                    region = self.source.consume_not_equal()
                else:
                    region = self.source.consume(child)
                child = self.source[region[0]:region[1]]
                token_start = region[0]
            if not first_token:
                formats.append(self.source[offset:token_start])
                if self.children:
                    children.append(self.source[offset:token_start])
            else:
                first_token = False
                start = token_start
            if self.children:
                children.append(child)
        start = self._handle_parens(children, start, formats)
        if eat_parens:
            start = self._eat_surrounding_parens(
                children, suspected_start, start)
        if eat_spaces:
            if self.children:
                children.appendleft(self.source[0:start])
            end_spaces = self.source[self.source.offset:]
            self.source.consume(end_spaces)
            if self.children:
                children.append(end_spaces)
            start = 0
        if self.children:
            node.sorted_children = children
        node.region = (start, self.source.offset)
        self.children_stack.pop()

    def _handle_parens(self, children, start, formats):
        """Changes `children` and returns new start"""
        opens, closes = self._count_needed_parens(formats)
        old_end = self.source.offset
        new_end = None
        for i in range(closes):
            new_end = self.source.consume(')')[1]
        if new_end is not None:
            if self.children:
                children.append(self.source[old_end:new_end])
        new_start = start
        for i in range(opens):
            new_start = self.source.rfind_token('(', 0, new_start)
        if new_start != start:
            if self.children:
                children.appendleft(self.source[new_start:start])
            start = new_start
        return start

    def _eat_surrounding_parens(self, children, suspected_start, start):
        index = self.source.rfind_token('(', suspected_start, start)
        if index is not None:
            old_start = start
            old_offset = self.source.offset
            start = index
            if self.children:
                children.appendleft(self.source[start + 1:old_start])
                children.appendleft('(')
            token_start, token_end = self.source.consume(')')
            if self.children:
                children.append(self.source[old_offset:token_start])
                children.append(')')
        return start

    def _count_needed_parens(self, children):
        start = 0
        opens = 0
        for child in children:
            if not isinstance(child, basestring):
                continue
            if child == '' or child[0] in '\'"':
                continue
            index = 0
            while index < len(child):
                if child[index] == ')':
                    if opens > 0:
                        opens -= 1
                    else:
                        start += 1
                if child[index] == '(':
                    opens += 1
                if child[index] == '#':
                    try:
                        index = child.index('\n', index)
                    except ValueError:
                        break
                index += 1
        return start, opens

    def _find_next_statement_start(self):
        for children in reversed(self.children_stack):
            for child in children:
                if isinstance(child, ast.stmt):
                    return self.lines.get_line_start(child.lineno)
        return len(self.source.source)

    _operators = {'And': 'and', 'Or': 'or', 'Add': '+', 'Sub': '-', 'Mult': '*',
                  'Div': '/', 'Mod': '%', 'Pow': '**', 'LShift': '<<',
                  'RShift': '>>', 'BitOr': '|', 'BitAnd': '&', 'BitXor': '^',
                  'FloorDiv': '//', 'Invert': '~', 'Not': 'not', 'UAdd': '+',
                  'USub': '-', 'Eq': '==', 'NotEq': '!=', 'Lt': '<',
                  'LtE': '<=', 'Gt': '>', 'GtE': '>=', 'Is': 'is',
                  'IsNot': 'is not', 'In': 'in', 'NotIn': 'not in'}

    def _get_op(self, node):
        return self._operators[node.__class__.__name__].split(' ')

    def _Attribute(self, node):
        self._handle(node, [node.value, '.', node.attr])

    def _Assert(self, node):
        children = ['assert', node.test]
        if node.msg:
            children.append(',')
            children.append(node.msg)
        self._handle(node, children)

    def _Assign(self, node):
        children = self._child_nodes(node.targets, '=')
        children.append('=')
        children.append(node.value)
        self._handle(node, children)

    def _AugAssign(self, node):
        children = [node.target]
        children.extend(self._get_op(node.op))
        children.extend(['=', node.value])
        self._handle(node, children)

    def _Repr(self, node):
        self._handle(node, ['`', node.value, '`'])

    def _BinOp(self, node):
        children = [node.left] + self._get_op(node.op) + [node.right]
        self._handle(node, children)

    def _BoolOp(self, node):
        self._handle(node, self._child_nodes(node.values,
                                             self._get_op(node.op)[0]))

    def _Break(self, node):
        self._handle(node, ['break'])

    def _Call(self, node):
        children = [node.func, '(']
        args = list(node.args) + node.keywords
        children.extend(self._child_nodes(args, ','))
        if node.starargs is not None:
            if args:
                children.append(',')
            children.extend(['*', node.starargs])
        if node.kwargs is not None:
            if args or node.starargs is not None:
                children.append(',')
            children.extend(['**', node.kwargs])
        children.append(')')
        self._handle(node, children)

    def _ClassDef(self, node):
        children = []
        if getattr(node, 'decorator_list', None):
            for decorator in node.decorator_list:
                children.append('@')
                children.append(decorator)
        children.extend(['class', node.name])
        if node.bases:
            children.append('(')
            children.extend(self._child_nodes(node.bases, ','))
            children.append(')')
        children.append(':')
        children.extend(node.body)
        self._handle(node, children)

    def _Compare(self, node):
        children = []
        children.append(node.left)
        for op, expr in zip(node.ops, node.comparators):
            children.extend(self._get_op(op))
            children.append(expr)
        self._handle(node, children)

    def _Delete(self, node):
        self._handle(node, ['del'] + self._child_nodes(node.targets, ','))

    def _Num(self, node):
        self._handle(node, [self.Number])

    def _Str(self, node):
        self._handle(node, [self.String])

    def _Continue(self, node):
        self._handle(node, ['continue'])

    def _Dict(self, node):
        children = []
        children.append('{')
        if node.keys:
            for index, (key, value) in enumerate(zip(node.keys, node.values)):
                children.extend([key, ':', value])
                if index < len(node.keys) - 1:
                    children.append(',')
        children.append('}')
        self._handle(node, children)

    def _Ellipsis(self, node):
        self._handle(node, ['...'])

    def _Expr(self, node):
        self._handle(node, [node.value])

    def _Exec(self, node):
        children = []
        children.extend(['exec', node.body])
        if node.globals:
            children.extend(['in', node.globals])
        if node.locals:
            children.extend([',', node.locals])
        self._handle(node, children)

    def _For(self, node):
        children = ['for', node.target, 'in', node.iter, ':']
        children.extend(node.body)
        if node.orelse:
            children.extend(['else', ':'])
            children.extend(node.orelse)
        self._handle(node, children)

    def _ImportFrom(self, node):
        children = ['from']
        if node.level:
            children.append('.' * node.level)
        children.extend([node.module, 'import'])
        children.extend(self._child_nodes(node.names, ','))
        self._handle(node, children)

    def _alias(self, node):
        children = [node.name]
        if node.asname:
            children.extend(['as', node.asname])
        self._handle(node, children)

    def _FunctionDef(self, node):
        children = []
        try:
            decorators = getattr(node, 'decorator_list')
        except AttributeError:
            decorators = getattr(node, 'decorators', None)
        if decorators:
            for decorator in decorators:
                children.append('@')
                children.append(decorator)
        children.extend(['def', node.name, '(', node.args])
        children.extend([')', ':'])
        children.extend(node.body)
        self._handle(node, children)

    def _arguments(self, node):
        children = []
        args = list(node.args)
        defaults = [None] * (len(args) - len(node.defaults)) + list(node.defaults)
        for index, (arg, default) in enumerate(zip(args, defaults)):
            if index > 0:
                children.append(',')
            self._add_args_to_children(children, arg, default)
        if node.vararg is not None:
            if args:
                children.append(',')
            children.extend(['*', node.vararg])
        if node.kwarg is not None:
            if args or node.vararg is not None:
                children.append(',')
            children.extend(['**', node.kwarg])
        self._handle(node, children)

    def _add_args_to_children(self, children, arg, default):
        if isinstance(arg, (list, tuple)):
            self._add_tuple_parameter(children, arg)
        else:
            children.append(arg)
        if default is not None:
            children.append('=')
            children.append(default)

    def _add_tuple_parameter(self, children, arg):
        children.append('(')
        for index, token in enumerate(arg):
            if index > 0:
                children.append(',')
            if isinstance(token, (list, tuple)):
                self._add_tuple_parameter(children, token)
            else:
                children.append(token)
        children.append(')')

    def _GeneratorExp(self, node):
        children = [node.elt]
        children.extend(node.generators)
        self._handle(node, children, eat_parens=True)

    def _comprehension(self, node):
        children = ['for', node.target, 'in', node.iter]
        if node.ifs:
            for if_ in node.ifs:
                children.append('if')
                children.append(if_)
        self._handle(node, children)

    def _Global(self, node):
        children = self._child_nodes(node.names, ',')
        children.insert(0, 'global')
        self._handle(node, children)

    def _If(self, node):
        if self._is_elif(node):
            children = ['elif']
        else:
            children = ['if']
        children.extend([node.test, ':'])
        children.extend(node.body)
        if node.orelse:
            if len(node.orelse) == 1 and self._is_elif(node.orelse[0]):
                pass
            else:
                children.extend(['else', ':'])
            children.extend(node.orelse)
        self._handle(node, children)

    def _is_elif(self, node):
        if not isinstance(node, ast.If):
            return False
        offset = self.lines.get_line_start(node.lineno) + node.col_offset
        word = self.source[offset:offset + 4]
        # XXX: This is a bug; the offset does not point to the first
        alt_word = self.source[offset - 5:offset - 1]
        return 'elif' in (word, alt_word)

    def _IfExp(self, node):
        return self._handle(node, [node.body, 'if', node.test,
                                   'else', node.orelse])

    def _Import(self, node):
        children = ['import']
        children.extend(self._child_nodes(node.names, ','))
        self._handle(node, children)

    def _keyword(self, node):
        self._handle(node, [node.arg, '=', node.value])

    def _Lambda(self, node):
        self._handle(node, ['lambda', node.args, ':', node.body])

    def _List(self, node):
        self._handle(node, ['['] + self._child_nodes(node.elts, ',') + [']'])

    def _ListComp(self, node):
        children = ['[', node.elt]
        children.extend(node.generators)
        children.append(']')
        self._handle(node, children)

    def _Module(self, node):
        self._handle(node, list(node.body), eat_spaces=True)

    def _Name(self, node):
        self._handle(node, [node.id])

    def _Pass(self, node):
        self._handle(node, ['pass'])

    def _Print(self, node):
        children = ['print']
        if node.dest:
            children.extend(['>>', node.dest])
            if node.values:
                children.append(',')
        children.extend(self._child_nodes(node.values, ','))
        if not node.nl:
            children.append(',')
        self._handle(node, children)

    def _Raise(self, node):
        children = ['raise']
        if node.type:
            children.append(node.type)
        if node.inst:
            children.append(',')
            children.append(node.inst)
        if node.tback:
            children.append(',')
            children.append(node.tback)
        self._handle(node, children)

    def _Return(self, node):
        children = ['return']
        if node.value:
            children.append(node.value)
        self._handle(node, children)

    def _Sliceobj(self, node):
        children = []
        for index, slice in enumerate(node.nodes):
            if index > 0:
                children.append(':')
            if slice:
                children.append(slice)
        self._handle(node, children)

    def _Index(self, node):
        self._handle(node, [node.value])

    def _Subscript(self, node):
        self._handle(node, [node.value, '[', node.slice, ']'])

    def _Slice(self, node):
        children = []
        if node.lower:
            children.append(node.lower)
        children.append(':')
        if node.upper:
            children.append(node.upper)
        if node.step:
            children.append(':')
            children.append(node.step)
        self._handle(node, children)

    def _TryFinally(self, node):
        children = []
        if len(node.body) != 1 or not isinstance(node.body[0], ast.TryExcept):
            children.extend(['try', ':'])
        children.extend(node.body)
        children.extend(['finally', ':'])
        children.extend(node.finalbody)
        self._handle(node, children)

    def _TryExcept(self, node):
        children = ['try', ':']
        children.extend(node.body)
        children.extend(node.handlers)
        if node.orelse:
            children.extend(['else', ':'])
            children.extend(node.orelse)
        self._handle(node, children)

    def _ExceptHandler(self, node):
        self._excepthandler(node)

    def _excepthandler(self, node):
        children = ['except']
        if node.type:
            children.append(node.type)
        if node.name:
            children.extend([',', node.name])
        children.append(':')
        children.extend(node.body)
        self._handle(node, children)

    def _Tuple(self, node):
        if node.elts:
            self._handle(node, self._child_nodes(node.elts, ','),
                         eat_parens=True)
        else:
            self._handle(node, ['(', ')'])

    def _UnaryOp(self, node):
        children = self._get_op(node.op)
        children.append(node.operand)
        self._handle(node, children)

    def _Yield(self, node):
        children = ['yield']
        if node.value:
            children.append(node.value)
        self._handle(node, children)

    def _While(self, node):
        children = ['while', node.test, ':']
        children.extend(node.body)
        if node.orelse:
            children.extend(['else', ':'])
            children.extend(node.orelse)
        self._handle(node, children)

    def _With(self, node):
        children = ['with', node.context_expr]
        if node.optional_vars:
            children.extend(['as', node.optional_vars])
        children.append(':')
        children.extend(node.body)
        self._handle(node, children)

    def _child_nodes(self, nodes, separator):
        children = []
        for index, child in enumerate(nodes):
            children.append(child)
            if index < len(nodes) - 1:
                children.append(separator)
        return children


class _Source(object):

    def __init__(self, source):
        self.source = source
        self.offset = 0

    def consume(self, token):
        try:
            while True:
                new_offset = self.source.index(token, self.offset)
                if self._good_token(token, new_offset):
                    break
                else:
                    self._skip_comment()
        except (ValueError, TypeError):
            raise MismatchedTokenError(
                'Token <%s> at %s cannot be matched' %
                (token, self._get_location()))
        self.offset = new_offset + len(token)
        return (new_offset, self.offset)

    def consume_string(self, end=None):
        if _Source._string_pattern is None:
            original = codeanalyze.get_string_pattern()
            pattern = r'(%s)((\s|\\\n|#[^\n]*\n)*(%s))*' % \
                      (original, original)
            _Source._string_pattern = re.compile(pattern)
        repattern = _Source._string_pattern
        return self._consume_pattern(repattern, end)

    def consume_number(self):
        if _Source._number_pattern is None:
            _Source._number_pattern = re.compile(
                self._get_number_pattern())
        repattern = _Source._number_pattern
        return self._consume_pattern(repattern)

    def consume_not_equal(self):
        if _Source._not_equals_pattern is None:
            _Source._not_equals_pattern = re.compile(r'<>|!=')
        repattern = _Source._not_equals_pattern
        return self._consume_pattern(repattern)

    def _good_token(self, token, offset, start=None):
        """Checks whether consumed token is in comments"""
        if start is None:
            start = self.offset
        try:
            comment_index = self.source.rindex('#', start, offset)
        except ValueError:
            return True
        try:
            new_line_index = self.source.rindex('\n', start, offset)
        except ValueError:
            return False
        return comment_index < new_line_index

    def _skip_comment(self):
        self.offset = self.source.index('\n', self.offset + 1)

    def _get_location(self):
        lines = self.source[:self.offset].split('\n')
        return (len(lines), len(lines[-1]))

    def _consume_pattern(self, repattern, end=None):
        while True:
            if end is None:
                end = len(self.source)
            match = repattern.search(self.source, self.offset, end)
            if self._good_token(match.group(), match.start()):
                break
            else:
                self._skip_comment()
        self.offset = match.end()
        return match.start(), match.end()

    def till_token(self, token):
        new_offset = self.source.index(token, self.offset)
        return self[self.offset:new_offset]

    def rfind_token(self, token, start, end):
        index = start
        while True:
            try:
                index = self.source.rindex(token, start, end)
                if self._good_token(token, index, start=start):
                    return index
                else:
                    end = index
            except ValueError:
                return None

    def from_offset(self, offset):
        return self[offset:self.offset]

    def find_backwards(self, pattern, offset):
        return self.source.rindex(pattern, 0, offset)

    def __getitem__(self, index):
        return self.source[index]

    def __getslice__(self, i, j):
        return self.source[i:j]

    def _get_number_pattern(self):
        # HACK: It is merely an approaximation and does the job
        integer = r'(0|0x)?[\da-fA-F]+[lL]?'
        return r'(%s(\.\d*)?|(\.\d+))([eE][-+]?\d*)?[jJ]?' % integer

    _string_pattern = None
    _number_pattern = None
    _not_equals_pattern = None
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.