[#71815] [Ruby trunk - Bug #11768] [Open] Add a polymorphic inline cache — tenderlove@...
Issue #11768 has been reported by Aaron Patterson.
6 messages
2015/12/03
[#71819] Re: [Ruby trunk - Bug #11768] [Open] Add a polymorphic inline cache
— Eric Wong <normalperson@...>
2015/12/03
tenderlove@ruby-lang.org wrote:
[#71821] Re: [Ruby trunk - Bug #11768] [Open] Add a polymorphic inline cache
— Aaron Patterson <tenderlove@...>
2015/12/03
On Thu, Dec 03, 2015 at 10:51:08PM +0000, Eric Wong wrote:
[#71824] Re: [Ruby trunk - Bug #11768] [Open] Add a polymorphic inline cache
— Eric Wong <normalperson@...>
2015/12/04
Aaron Patterson <tenderlove@ruby-lang.org> wrote:
[#71818] [Ruby trunk - Feature #11769] [Open] optimize case / when for `nil` — tenderlove@...
Issue #11769 has been reported by Aaron Patterson.
4 messages
2015/12/03
[#71825] Re: [Ruby trunk - Feature #11769] [Open] optimize case / when for `nil`
— Eric Wong <normalperson@...>
2015/12/04
tenderlove@ruby-lang.org wrote:
[#71931] [Ruby trunk - Feature #11786] [Open] [PATCH] micro-optimize case dispatch even harder — normalperson@...
Issue #11786 has been reported by Eric Wong.
9 messages
2015/12/08
[#71932] Re: [Ruby trunk - Feature #11786] [Open] [PATCH] micro-optimize case dispatch even harder
— Eric Wong <normalperson@...>
2015/12/08
Oops, I forgot to free the table when iseq is destroyed :x
[#71934] Re: [Ruby trunk - Feature #11786] [Open] [PATCH] micro-optimize case dispatch even harder
— SASADA Koichi <ko1@...>
2015/12/08
On 2015/12/08 12:43, Eric Wong wrote:
[#71936] Re: [Ruby trunk - Feature #11786] [Open] [PATCH] micro-optimize case dispatch even harder
— Eric Wong <normalperson@...>
2015/12/08
SASADA Koichi <ko1@atdot.net> wrote:
[#71938] Re: [Ruby trunk - Feature #11786] [Open] [PATCH] micro-optimize case dispatch even harder
— SASADA Koichi <ko1@...>
2015/12/08
On 2015/12/08 13:53, Eric Wong wrote:
[#72028] [Ruby trunk - Feature #11405] [Assigned] [PATCH] hash.c: minor speedups to int/fixnum keys — mame@...
Issue #11405 has been updated by Yusuke Endoh.
5 messages
2015/12/10
[#72040] Re: [Ruby trunk - Feature #11405] [Assigned] [PATCH] hash.c: minor speedups to int/fixnum keys
— Eric Wong <normalperson@...>
2015/12/10
mame@ruby-lang.org wrote:
[#72045] Ruby 2.3.0-preview2 Released — "NARUSE, Yui" <naruse@...>
We are pleased to announce the release of Ruby 2.3.0-preview2.
10 messages
2015/12/11
[#72047] Re: Ruby 2.3.0-preview2 Released
— SASADA Koichi <ko1@...>
2015/12/11
Please add your optimizations before RC1.
[#72054] Re: Ruby 2.3.0-preview2 Released
— Eric Wong <normalperson@...>
2015/12/11
SASADA Koichi <ko1@atdot.net> wrote:
[#72436] Re: Ruby 2.3.0-preview2 Released
— SASADA Koichi <ko1@...>
2015/12/22
On 2015/12/11 18:06, Eric Wong wrote:
[#72440] Re: Ruby 2.3.0-preview2 Released
— Eric Wong <normalperson@...>
2015/12/22
SASADA Koichi <ko1@atdot.net> wrote:
[#72069] [Ruby trunk - Feature #11405] [PATCH] hash.c: minor speedups to int/fixnum keys — mame@...
Issue #11405 has been updated by Yusuke Endoh.
3 messages
2015/12/12
[#72115] Re: [ruby-cvs:60264] duerst:r53112 (trunk): * enc/ebcdic.h: new dummy encoding EBCDIC-US — "U.NAKAMURA" <usa@...>
Hi,
7 messages
2015/12/14
[#72124] Re: [ruby-cvs:60264] duerst:r53112 (trunk): * enc/ebcdic.h: new dummy encoding EBCDIC-US
— Martin J. Dürst <duerst@...>
2015/12/14
On 2015/12/14 22:34, U.NAKAMURA wrote:
[#72125] Re: [ruby-cvs:60264] duerst:r53112 (trunk): * enc/ebcdic.h: new dummy encoding EBCDIC-US
— "U.NAKAMURA" <usa@...>
2015/12/15
Hi,
[ruby-core:72363] [Ruby trunk - Feature #11815] Proposal for method `Array#difference`
From:
duerst@...
Date:
2015-12-18 10:17:39 UTC
List:
ruby-core #72363
Issue #11815 has been updated by Martin D端rst.
Ryan Beltran wrote:
> I think I have a pretty good example. I'm implementing a function in Ruby that finds triples in an array for use in a pokerbot (recognizes if a hand is a triple). I already defined a function to check for doubles (which is relatively trivial to implement by comparing the original array to array.uniq), but triples are a little bit harder. There are several ways I could implement checking for triples, but a concise and efficient option would be to simply call:
>
> `getDoubles(array.difference(array.uniq))`
>
> ~~~ ruby
> doubles = array.difference(array.uniq)
> triples = doubles.difference(doubles)
> fours = triples.difference(triples)
> ~~~
An even more straightforward way is to use group_by:
~~~ ruby
n_tuples = array.group_by {|e| e}.values.group_by(&:length)
doubles = n_tuples[2]
triples = n_tuples[3]
fours = n_tuples[4]
# and so on
~~~ ruby
We need group_by two times because the first one groups items with the same value, and the second organizes these by numbers. As an example, if we start with [1,2,2,3,3,3,4,4,4,4,5,5,5,7,8,8] then after the first group_by, we have
{1=>[1], 2=>[2, 2], 3=>[3, 3, 3], 4=>[4, 4, 4, 4], 5=>[5, 5, 5], 7=>[7], 8=>[8, 8]}.
Of this, we only need the values: [[1], [2, 2], [3, 3, 3], [4, 4, 4, 4], [5, 5, 5], [7], [8, 8]].
Then we group by length and get:
{1=>[[1], [7]], 2=>[[2, 2], [8, 8]], 3=>[[3, 3, 3], [5, 5, 5]], 4=>[[4, 4, 4, 4]]}
To get an unique value (i.e. 3 instead of [3, 3, 3]), just use .map(&:first).
----------------------------------------
Feature #11815: Proposal for method `Array#difference`
https://bugs.ruby-lang.org/issues/11815#change-55656
* Author: Cary Swoveland
* Status: Open
* Priority: Normal
* Assignee:
----------------------------------------
I propose that a method `Array#difference` be added to the Ruby core. It is similar to [Array#-](http://ruby-doc.org/core-2.2.0/Array.html#method-i-2D) but for each element of the (array) argument it removes only one matching element from the receiver. For example:
a = [1,2,3,4,3,2,2,4]
b = [2,3,4,4,4]
a - b #=> [1]
c = a.difference b #=> [1, 3, 2, 2]
As you see, `a` contains three `2`'s and `b` contains `1`, so the first `2` in `a` has been removed from `a` in constructing `c`. When `b` contains as least as many instances of an element as does `a`, `c` contains no instances of that element.
It could be implemented as follows:
class Array
def difference(other)
dup.tap do |cpy|
other.each do |e|
ndx = cpy.index(e)
cpy.delete_at(ndx) if ndx
end
end
end
end
Here are a few examples of its use:
*Identify an array's unique elements*
a = [1,3,2,4,3,4]
u = a.uniq #=> [1, 2, 3, 4]
u - a.difference(u) #=> [1, 2]
*Determine if two words of the same size are anagrams of each other*
w1, w2 = "stop", "pots"
w1.chars.difference(w2.chars).empty?
#=> true
*Identify a maximal number of 1-1 matches between the elements of two arrays and return an array of all elements from both arrays that were not matched*
a = [1, 2, 4, 2, 1, 7, 4, 2, 9]
b = [4, 7, 3, 2, 2, 7]
a.difference(b).concat(b.difference(a))
#=> [1, 1, 4, 2, 9, 3, 7]
To remove elements from `a` starting at the end (rather the beginning) of `a`:
a = [1,2,3,4,3,2,2,4]
b = [2,3,4,4,4]
a.reverse.difference(b).reverse #=> [1,2,3,2]
`Array#difference!` could be defined in the obvious way.
--
https://bugs.ruby-lang.org/