107 lines
3.4 KiB
Ruby
107 lines
3.4 KiB
Ruby
require 'enumerator'
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module ActiveSupport #:nodoc:
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module CoreExtensions #:nodoc:
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module Array #:nodoc:
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module Grouping
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# Splits or iterates over the array in groups of size +number+,
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# padding any remaining slots with +fill_with+ unless it is +false+.
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#
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# %w(1 2 3 4 5 6 7).in_groups_of(3) {|group| p group}
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# ["1", "2", "3"]
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# ["4", "5", "6"]
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# ["7", nil, nil]
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#
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# %w(1 2 3).in_groups_of(2, ' ') {|group| p group}
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# ["1", "2"]
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# ["3", " "]
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#
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# %w(1 2 3).in_groups_of(2, false) {|group| p group}
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# ["1", "2"]
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# ["3"]
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def in_groups_of(number, fill_with = nil)
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if fill_with == false
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collection = self
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else
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# size % number gives how many extra we have;
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# subtracting from number gives how many to add;
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# modulo number ensures we don't add group of just fill.
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padding = (number - size % number) % number
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collection = dup.concat([fill_with] * padding)
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end
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if block_given?
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collection.each_slice(number) { |slice| yield(slice) }
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else
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[].tap do |groups|
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collection.each_slice(number) { |group| groups << group }
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end
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end
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end
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# Splits or iterates over the array in +number+ of groups, padding any
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# remaining slots with +fill_with+ unless it is +false+.
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#
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# %w(1 2 3 4 5 6 7 8 9 10).in_groups(3) {|group| p group}
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# ["1", "2", "3", "4"]
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# ["5", "6", "7", nil]
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# ["8", "9", "10", nil]
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#
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# %w(1 2 3 4 5 6 7).in_groups(3, ' ') {|group| p group}
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# ["1", "2", "3"]
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# ["4", "5", " "]
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# ["6", "7", " "]
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#
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# %w(1 2 3 4 5 6 7).in_groups(3, false) {|group| p group}
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# ["1", "2", "3"]
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# ["4", "5"]
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# ["6", "7"]
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def in_groups(number, fill_with = nil)
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# size / number gives minor group size;
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# size % number gives how many objects need extra accomodation;
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# each group hold either division or division + 1 items.
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division = size / number
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modulo = size % number
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# create a new array avoiding dup
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groups = []
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start = 0
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number.times do |index|
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length = division + (modulo > 0 && modulo > index ? 1 : 0)
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padding = fill_with != false &&
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modulo > 0 && length == division ? 1 : 0
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groups << slice(start, length).concat([fill_with] * padding)
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start += length
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end
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if block_given?
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groups.each{|g| yield(g) }
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else
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groups
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end
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end
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# Divides the array into one or more subarrays based on a delimiting +value+
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# or the result of an optional block.
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#
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# [1, 2, 3, 4, 5].split(3) # => [[1, 2], [4, 5]]
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# (1..10).to_a.split { |i| i % 3 == 0 } # => [[1, 2], [4, 5], [7, 8], [10]]
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def split(value = nil)
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using_block = block_given?
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inject([[]]) do |results, element|
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if (using_block && yield(element)) || (value == element)
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results << []
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else
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results.last << element
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end
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results
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end
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end
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end
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end
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end
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end
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