Class: Array

Inherits:
Object show all
Defined in:
lib/mug/top.rb,
lib/mug/bool.rb,
lib/mug/array/minus.rb,
lib/mug/array/extend.rb,
lib/mug/array/samples.rb,
lib/mug/array/to_proc.rb,
lib/mug/array/delete_all.rb

Instance Method Summary collapse

Instance Method Details

#^(other) ⇒ Array

Get the elements unique to one of two arrays.

Duplicates in either array are included only once.

Parameters:

  • other (Array) —

    the array to compare against

Returns:

  • (Array) —

    elements unique to one of the two arrays



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# File 'lib/mug/array/minus.rb', line 53

def ^ other
  left = uniq
  right = []
  other.uniq.each do |x|
    if left.include? x
      left.delete x
    elsif ! right.include?(x)
      right << x
    end
  end
  left + right
end

#bottom!(n = 1) {|a, b| ... } ⇒ Array

Replaces this array with the bottom n items in place.

Parameters:

  • n (Integer) (defaults to: 1) —

    the number of items to keep

Yields:

  • (a, b) —

    optional comparison block

Returns:

See Also:



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# File 'lib/mug/top.rb', line 159

def bottom! n=1, &blk
  replace bottom(n, &blk)
end

#bottom_by!(n = 1) {|item| ... } ⇒ Array, Enumerator

Replaces this array with the bottom n items (by mapping) in place.

Parameters:

  • n (Integer) (defaults to: 1) —

    the number of items to keep

Yields:

  • (item) —

    mapping block

Returns:

See Also:



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# File 'lib/mug/top.rb', line 170

def bottom_by! n=1, &blk
  return enum_for(:bottom_by!, n) unless block_given?
  replace bottom_by(n, &blk)
end

#delete_all {|item| ... } ⇒ Array, Enumerator

Deletes every element of self for which block evaluates to true.

Returns an array of the deleted elements.

If no block is given, an Enumerator is returned instead.

Yields:

  • (item) —

    block that determines whether to delete

Returns:

See Also:



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# File 'lib/mug/array/delete_all.rb', line 18

def delete_all &_block
  return enum_for :delete_all unless block_given?
  [].tap do |removed|
    delete_if do |e|
      if yield e
        removed << e
        true
      end
    end
  end
end

#extend ⇒ Object

See Also:



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# File 'lib/mug/array/extend.rb', line 48

def extend(...)
  dup.extend!(...)
end

#extend!(size, *rest) ⇒ Object

Extend this Array.

In the first form, when a size and an optional obj are sent, the array is extended with size copies of obj. Take notice that all elements will reference the same object obj.

The second form appends a copy of the array passed as a parameter (the array is generated by calling #to_ary on the parameter). In the last form, the array is extended by the given size. Each new element in the array is created by passing the element's index to the given block and storing the return value.

@call-seq extend!(size=0, obj=nil) @call-seq extend!(array) @call-seq extend!(size) {|index| block }

Raises:

  • (ArgumentError)

See Also:

  • #concat
  • #+


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# File 'lib/mug/array/extend.rb', line 24

def extend! size, *rest
  raise ArgumentError, "wrong number of arguments (#{rest.length+1} for 1..2)" if rest.length > 1

  # Same logic as array.c/rb_ary_initialize
  if rest.empty? && !size.is_a?(Integer)
    warn 'warning: given block not used' if block_given?
    concat size.to_ary
    return self
  end

  raise ArgumentError, 'negative size' if size < 0

  a = length
  b = a+size
  if block_given?
    warn 'warning: block supersedes default value argument' if !rest.empty?
    fill(a...b) {|i| yield i }
  else
    obj = rest[0]
    fill(a...b) { obj }
  end
end

#minus(ary, remainder: false) ⇒ Array

Note:

For the single-argument case, Array#minus is similar to Array#difference (Ruby 2.6+). The remainder: option and Array#^ have no stdlib equivalent.

Subtract elements from this array.

This is similar to Array#- except that elements from this array are removed only once per instance in ary.

If remainder is given and true, returns a second array which is all elements in ary that were not present in this array.

@call-seq minus(ary) @call-seq minus(ary, remainder: true)

Parameters:

  • ary (Array) —

    elements to subtract

  • remainder (Boolean) (defaults to: false) —

    whether to return unmatched elements from ary

Returns:

  • (Array) —

    the resulting array (or a pair of arrays if remainder: is true)



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# File 'lib/mug/array/minus.rb', line 24

def minus ary, remainder: false

  result = dup
  rem = []

  ary.each do |x|
    i = result.index x
    if i
      result.delete_at i
    elsif remainder
      rem << x
    end
  end

  if remainder
    [result, rem]
  else
    result
  end
end

#samples(min: nil, max: nil, random: nil) ⇒ Array

Choose a random subset of elements from the array.

The elements are chosen by using random and unique indices into the array in order to ensure that an element doesn't repeat itself unless the array already contained duplicate elements.

If the array is empty, always returns an empty array.

The optional min and max arguments restrict the size of the returned array. min must be >= 0, and max must be >= min. (Both values are clamped to the size of the array.)

The optional random argument will be used as the random number generator.

Parameters:

  • min (Integer) (defaults to: nil) —

    minimum subset size (default: 1)

  • max (Integer) (defaults to: nil) —

    maximum subset size (default: array length)

  • random (#rand) (defaults to: nil) —

    random number generator

Returns:

  • (Array) —

    a new array containing the random subset

Raises:

  • (ArgumentError) 


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# File 'lib/mug/array/samples.rb', line 25

def samples min: nil, max: nil, random: nil
  min = 1 if min.nil?
  min = length if min > length

  max = length if max.nil?
  max = length if max > length

  raise ArgumentError, "min must be >= 0 (#{min})" if min < 0
  raise ArgumentError, "min (#{min}) must be <= max (#{max})" if min > max

  if random
    n = random.rand(min..max)
    sample n, random: random
  else
    n = rand(min..max)
    sample n
  end
end

#to_b ⇒ Boolean

Converts ary to a boolean. Returns true if not empty.

Returns:

  • (Boolean) —

    true if self is non-empty



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# File 'lib/mug/bool.rb', line 112

def to_b
  !empty?
end

#to_proc ⇒ Proc

Returns a Proc that accepts one or two arguments.

The Proc's parameter is used as an index into this array.

Examples:

require 'mug/array/to_proc'

lookup = ['zero', 'one', 'two']
[0, 2, 1].map(&lookup) #=> ['zero', 'two', 'one']

Returns:

  • (Proc) —

    a proc that indexes into this array

See Also:

  • #slice


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# File 'lib/mug/array/to_proc.rb', line 18

def to_proc
  method(:slice).to_proc
end

#top!(n = 1) {|a, b| ... } ⇒ Array

Replaces this array with the top n items in place.

Parameters:

  • n (Integer) (defaults to: 1) —

    the number of items to keep

Yields:

  • (a, b) —

    optional comparison block

Returns:

See Also:



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# File 'lib/mug/top.rb', line 137

def top! n=1, &blk
  replace top(n, &blk)
end

#top_by!(n = 1) {|item| ... } ⇒ Array, Enumerator

Replaces this array with the top n items (by mapping) in place.

Parameters:

  • n (Integer) (defaults to: 1) —

    the number of items to keep

Yields:

  • (item) —

    mapping block

Returns:

See Also:



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# File 'lib/mug/top.rb', line 148

def top_by! n=1, &blk
  return enum_for(:top_by!, n) unless block_given?
  replace top_by(n, &blk)
end