Probaly still prefer: https://github.com/hashie/hashie over this

This doesn't actually seem to be an example of destructure/splat. (When it said "destructure the contents ... out to a block", I was surprised and confused, because splatting is when you splat it into an argument or another hash — never a block.)

An example of destructure/splat would be more like

method_that_takes_kwargs(**symbol_mash)

La colección (o contenedor) del STL que guarda pares ordenados key/value en un hash table se llama el unordered map.

hash the source/destination IP:port tuples to the same worker thread.

http://geohash.org/c216ne:Mt_Hood http://geohash.org/?q=45.37,-121.7&format=gpx http://geohash.org/?q=45.37,-121.7&format=url&redirect=0

• osm — open the location in OpenStreetMaps
• gmaps — open the location in Google Maps
• gc — go to the nearest geocaches in Geocaching.com
• gpx — go directly to GPX download page
• garmin — go directly to Garmin download page
• text — show coordinates as plain text
• url — show Geohash URL as plain text
• maxlen — maximum length of the Geohash

hash://sha256/9f86d081884c7d659a2feaa0?type=text/plain#top \__/ \____/ \______________________/ \_____________/ \_/ | | | | | scheme algorithm hash query fragment

Collision reduction in Hash Tables : Open Addressing

Didn't understand it at first, but now I think it's a pretty clever/decent solution.

Just a bit more verbose than one might like...

At first I had reservations about the fact that this requires you to pass a hash ... or rather, once you start using a hash as your "list", you can't just "switch back" to an array (a "problem" I've noticed in RSpec, where you have some tags that are symbols, and some that are hashes: you have to list the symbols first: describe 'thing', :happy_path, driver: :chrome):

{}.bury(users: Array, 0, 'Value')

But I think that's okay in practice. Just use a hash for all "elements" in your list:

{}.bury(users: Array, 0 => 'Value')

No docs?!

[ Some docs here; First saw it here: ] https://bugs.ruby-lang.org/issues/11747#note-7

equivalent in javascript:

{a, b, ...rest} = {a: 1, b: 2, c: 3, d: 4}

Not a bad replacement for that! I still find javascript's syntax a little more easily readable and natural, but given that we can't use the same syntax (probably because it would be incompatible with existing syntax rules that we can't break for compatibility reasons, unfortunately), this is a pretty good compromise/solution that they've come up with.

具体实现：

#!/usr/bin/python

import glob
import os
import sys

from PIL import Image

EXTS = 'jpg', 'jpeg', 'JPG', 'JPEG', 'gif', 'GIF', 'png', 'PNG'

def avhash(im):
    if not isinstance(im, Image.Image):
        im = Image.open(im)
    im = im.resize((8, 8), Image.ANTIALIAS).convert('L')
    avg = reduce(lambda x, y: x + y, im.getdata()) / 64.
    return reduce(lambda x, (y, z): x | (z << y),
                  enumerate(map(lambda i: 0 if i < avg else 1, im.getdata())),
                  0)

def hamming(h1, h2):
    h, d = 0, h1 ^ h2
    while d:
        h += 1
        d &= d - 1
    return h

if __name__ == '__main__':
    if len(sys.argv) <= 1 or len(sys.argv) > 3:
        print "Usage: %s image.jpg [dir]" % sys.argv[0]
    else:
        im, wd = sys.argv[1], '.' if len(sys.argv) < 3 else sys.argv[2]
        h = avhash(im)

        os.chdir(wd)
        images = []
        for ext in EXTS:
            images.extend(glob.glob('*.%s' % ext))

        seq = []
        prog = int(len(images) > 50 and sys.stdout.isatty())
        for f in images:
            seq.append((f, hamming(avhash(f), h)))
            if prog:
                perc = 100. * prog / len(images)
                x = int(2 * perc / 5)
                print '\rCalculating... [' + '#' * x + ' ' * (40 - x) + ']',
                print '%.2f%%' % perc, '(%d/%d)' % (prog, len(images)),
                sys.stdout.flush()
                prog += 1

        if prog: print
        for f, ham in sorted(seq, key=lambda i: i[1]):
            print "%d\t%s" % (ham, f)

参考代码：

1. http://www.ruanyifeng.com/blog/2011/07/imgHash.txt