Source

twoq / twoq / mapping.py

# -*- coding: utf-8 -*-
'''twoq mapping mixins'''

from time import sleep
from copy import deepcopy
from threading import local
from operator import methodcaller
from itertools import starmap, repeat

from twoq.support import imap, ichain, items, xrange


class DelayMixin(local):

    '''delayed map mixin'''

    def delay_each(self, wait):
        '''
        invoke call with passed arguments, keywords in incoming things after
        delay `wait`

        @param wait: time in seconds
        '''
        def delay_each(x, y, wait=0, caller=None):
            sleep(wait)
            return caller(*x, **y)
        with self._context():
            de, call = delay_each, self._call
            return self._xtend(starmap(
                lambda x, y: de(x, y, wait, call), self._iterable,
            ))

    def delay_invoke(self, name, wait):
        '''
        invoke method `name` on each incoming thing with passed arguments,
        keywords after delay `wait` but return incoming thing instead if method
        returns `None`

        @param name: name of method
        @param wait: time in seconds
        '''
        def delay_invoke(x, wait=0, caller=None):
            sleep(wait)
            results = caller(x)
            return x if results is None else results
        with self._context():
            di, mc = delay_invoke, methodcaller
            args, kw = self._args, self._kw
            return self._xtend(imap(
                lambda x: di(x, wait, mc(name, *args, **kw)), self._iterable,
            ))

    def delay_map(self, wait):
        '''
        invoke call on each incoming thing after delay `wait`

        @param wait: time in seconds
        '''
        def delay_map(x, wait=None, caller=None):
            sleep(wait)
            return caller(x)
        with self._context():
            dm, call = delay_map, self._call
            return self._xtend(imap(
                lambda x: dm(x, wait, call), self._iterable,
            ))


class RepeatMixin(local):

    '''repetition mixin'''

    def copy(self):
        '''copy each incoming thing'''
        with self._context():
            return self._xtend(imap(deepcopy, self._iterable))

    def range(self, start, stop=0, step=1):
        '''
        put sequence of numbers in incoming things

        @param start: number to start with
        @param stop: number to stop with (default: 0)
        @param step: number of steps to advance per iteration (default: 1)
        '''
        with self._context():
            return self._xtend(
                xrange(start, stop, step) if stop else xrange(start)
            )

    def repeat(self, n):
        '''
        repeat incoming things `n` times

        @param n: number of times to repeat
        '''
        with self._context():
            return self._xtend(repeat(tuple(self._iterable), n))

    def times(self, n=None):
        '''
        repeat call with incoming things `n` times

        @param n: repeat call n times on incoming things (default: None)
        '''
        with self._context():
            if n is None:
                return self._xtend(starmap(
                    self._call, repeat(list(self._iterable)),
                ))
            return self._xtend(starmap(
                self._call, repeat(list(self._iterable), n),
            ))


class MapMixin(local):

    '''mapping mixin'''

    def each(self):
        '''invoke call with passed arguments, keywords in incoming things'''
        with self._context():
            return self._xtend(starmap(
                lambda x, y: self._call(*x, **y), self._iterable,
            ))

    def invoke(self, name):
        '''
        invoke method `name` on each incoming thing with passed arguments,
        keywords but return incoming thing instead if method returns `None`

        @param name: name of method
        '''
        def invoke(thing, caller=None):
            results = caller(thing)
            return thing if results is None else results
        with self._context():
            return self._xtend(imap(
                lambda x: invoke(
                    x, caller=methodcaller(name, *self._args, **self._kw)
                ),
                self._iterable
            ))

    def items(self):
        '''invoke call on each mapping to get key, value pairs'''
        with self._context():
            return self._xtend(starmap(
                self._call, ichain(imap(items, self._iterable))
            ))

    def map(self):
        '''invoke call on each incoming thing'''
        with self._context():
            return self._xtend(imap(self._call, self._iterable))

    def starmap(self):
        '''invoke call on each sequence of incoming things'''
        with self._context():
            return self._xtend(starmap(self._call, self._iterable))


class MappingMixin(DelayMixin, RepeatMixin, MapMixin):

    '''mapping mixin'''