Mac Easy 2010 May/Mac Life Ubuntu.iso/casper/filesystem.squashfs/usr/lib/python2.6/lib2to3/fixes/fix_tuple_params.pyc

Python Compiled Bytecode | 2009-04-20 | 5.3 KB | 164 lines

# Source Generated with Decompyle++
# File: in.pyc (Python 2.6)

'''Fixer for function definitions with tuple parameters.

def func(((a, b), c), d):
    ...

    ->

def func(x, d):
    ((a, b), c) = x
    ...

It will also support lambdas:

    lambda (x, y): x + y -> lambda t: t[0] + t[1]

    # The parens are a syntax error in Python 3
    lambda (x): x + y -> lambda x: x + y
'''
from  import pytree
from pgen2 import token
from  import fixer_base
from fixer_util import Assign, Name, Newline, Number, Subscript, syms

def is_docstring(stmt):
    if isinstance(stmt, pytree.Node):
        pass
    return stmt.children[0].type == token.STRING


class FixTupleParams(fixer_base.BaseFix):
    PATTERN = "\n              funcdef< 'def' any parameters< '(' args=any ')' >\n                       ['->' any] ':' suite=any+ >\n              |\n              lambda=\n              lambdef< 'lambda' args=vfpdef< '(' inner=any ')' >\n                       ':' body=any\n              >\n              "

    def transform(self, node, results):
        if 'lambda' in results:
            return self.transform_lambda(node, results)
        new_lines = []
        suite = results['suite']
        args = results['args']
        if suite[0].children[1].type == token.INDENT:
            start = 2
            indent = suite[0].children[1].value
            end = Newline()
        else:
            start = 0
            indent = '; '
            end = pytree.Leaf(token.INDENT, '')

        def handle_tuple(tuple_arg, add_prefix = (None, None, False)):
            n = Name(self.new_name())
            arg = tuple_arg.clone()
            arg.set_prefix('')
            stmt = Assign(arg, n.clone())
            if add_prefix:
                n.set_prefix(' ')

            tuple_arg.replace(n)
            new_lines.append(pytree.Node(syms.simple_stmt, [
                stmt,
                end.clone()]))

        if args.type == syms.tfpdef:
            handle_tuple(args)
        elif args.type == syms.typedargslist:
            for i, arg in enumerate(args.children):
                if arg.type == syms.tfpdef:
                    handle_tuple(arg, add_prefix = i > 0)
                    continue


        if not new_lines:
            return node
        for line in new_lines:
            line.parent = suite[0]

        after = start
        if start == 0:
            new_lines[0].set_prefix(' ')
        elif is_docstring(suite[0].children[start]):
            new_lines[0].set_prefix(indent)
            after = start + 1

        suite[0].children[after:after] = new_lines
        for i in range(after + 1, after + len(new_lines) + 1):
            suite[0].children[i].set_prefix(indent)

        suite[0].changed()


    def transform_lambda(self, node, results):
        args = results['args']
        body = results['body']
        inner = simplify_args(results['inner'])
        if inner.type == token.NAME:
            inner = inner.clone()
            inner.set_prefix(' ')
            args.replace(inner)
            return None
        params = find_params(args)
        to_index = map_to_index(params)
        tup_name = self.new_name(tuple_name(params))
        new_param = Name(tup_name, prefix = ' ')
        args.replace(new_param.clone())
        for n in body.post_order():
            if n.type == token.NAME and n.value in to_index:
                subscripts = [ c.clone() for c in to_index[n.value] ]
                new = pytree.Node(syms.power, [
                    new_param.clone()] + subscripts)
                new.set_prefix(n.get_prefix())
                n.replace(new)
                continue
            []




def simplify_args(node):
    if node.type in (syms.vfplist, token.NAME):
        return node
    if node.type == syms.vfpdef:
        while node.type == syms.vfpdef:
            node = node.children[1]
            continue
            node.type in (syms.vfplist, token.NAME)
        return node
    raise RuntimeError('Received unexpected node %s' % node)


def find_params(node):
    if node.type == syms.vfpdef:
        return find_params(node.children[1])
    if node.type == token.NAME:
        return node.value
    return _[1]


def map_to_index(param_list, prefix = [], d = None):
    if d is None:
        d = { }

    for i, obj in enumerate(param_list):
        trailer = [
            Subscript(Number(i))]
        if isinstance(obj, list):
            map_to_index(obj, trailer, d = d)
            continue
        d[obj] = prefix + trailer

    return d


def tuple_name(param_list):
    l = []
    for obj in param_list:
        if isinstance(obj, list):
            l.append(tuple_name(obj))
            continue
        l.append(obj)

    return '_'.join(l)