Module: Enumerable

Included in:
Array, Enumerator, Enumerator::Chain, Enumerator::Generator, Hash, Range
Defined in:
mrblib/enum.rb,
src/enum.c,
mrbgems/mruby-enum-ext/mrblib/enum.rb,
mrbgems/mruby-enum-lazy/mrblib/lazy.rb,
mrbgems/mruby-enum-chain/mrblib/chain.rb,
mrbgems/mruby-enumerator/mrblib/enumerator.rb

Overview

chain.rb Enumerator::Chain class See Copyright Notice in mruby.h

Constant Summary collapse

NONE = 
Object.new

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.__update_hash ⇒ Object

internal method __update_hash(oldhash, index, itemhash)



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# File 'src/enum.c', line 11

static mrb_value
enum_update_hash(mrb_state *mrb, mrb_value self)
{
  mrb_int hash;
  mrb_int index;
  mrb_int hv;

  mrb_get_args(mrb, "iii", &hash, &index, &hv);
  hash ^= ((uint32_t)hv << (index % 16));

  return mrb_fixnum_value(hash);
}

Instance Method Details

#all?(pat = NONE, &block) ⇒ Boolean

ISO 15.3.2.2.1 call-seq: enum.all? [{ |obj| block } ] -> true or false enum.all?(pattern) -> true or false

Passes each element of the collection to the given block. The method returns true if the block never returns false or nil. If the block is not given, Ruby adds an implicit block of { |obj| obj } which will cause #all? to return +true+ when none of the collection members are +false+ or +nil+.

If a pattern is supplied instead, the method returns whether pattern === element for every collection member.

%w[ant bear cat].all? { |word| word.length >= 3 } #=> true
%w[ant bear cat].all? { |word| word.length >= 4 } #=> false
%w[ant bear cat].all?(/t/)                        #=> false
[1, 2i, 3.14].all?(Numeric)                       #=> true
[nil, true, 99].all?                              #=> false

Returns:

  • (Boolean) 


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# File 'mrblib/enum.rb', line 26

def all?(&block)
  if block
    self.each{|*val| return false unless block.call(*val)}
  else
    self.each{|*val| return false unless val.__svalue}
  end
  true
end

#any?(pat = NONE, &block) ⇒ Boolean

ISO 15.3.2.2.2 call-seq: enum.any? [{ |obj| block }] -> true or false enum.any?(pattern) -> true or false

Passes each element of the collection to the given block. The method returns true if the block ever returns a value other than false or nil. If the block is not given, Ruby adds an implicit block of { |obj| obj } that will cause #any? to return +true+ if at least one of the collection members is not +false+ or +nil+.

If a pattern is supplied instead, the method returns whether pattern === element for any collection member.

%w[ant bear cat].any? { |word| word.length >= 3 } #=> true
%w[ant bear cat].any? { |word| word.length >= 4 } #=> true
%w[ant bear cat].any?(/d/)                        #=> false
[nil, true, 99].any?(Integer)                     #=> true
[nil, true, 99].any?                              #=> true
[].any?                                           #=> false

Returns:

  • (Boolean) 


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# File 'mrblib/enum.rb', line 43

def any?(&block)
  if block
    self.each{|*val| return true if block.call(*val)}
  else
    self.each{|*val| return true if val.__svalue}
  end
  false
end

#chain(*args) ⇒ Object 



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# File 'mrbgems/mruby-enum-chain/mrblib/chain.rb', line 6

def chain(*args)
  Enumerator::Chain.new(self, *args)
end

#collect(&block) ⇒ Object Also known as: map

Call the given block for each element which is yield by +each+. Append all values of each block together and return this value.

ISO 15.3.2.2.3



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# File 'mrblib/enum.rb', line 59

def collect(&block)
  return to_enum :collect unless block

  ary = []
  self.each{|*val| ary.push(block.call(*val))}
  ary
end

#count(v = NONE, &block) ⇒ Object

call-seq: enum.count -> int enum.count(item) -> int enum.count { |obj| block } -> int

Returns the number of items in +enum+ through enumeration. If an argument is given, the number of items in +enum+ that are equal to +item+ are counted. If a block is given, it counts the number of elements yielding a true value.



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 249

def count(v=NONE, &block)
  count = 0
  if block
    self.each do |*val|
      count += 1 if block.call(*val)
    end
  else
    if v == NONE
      self.each { count += 1 }
    else
      self.each do |*val|
        count += 1 if val.__svalue == v
      end
    end
  end
  count
end

#cycle(nv = nil, &block) ⇒ Object

call-seq: enum.cycle(n=nil) { |obj| block } -> nil enum.cycle(n=nil) -> an_enumerator

Calls block for each element of enum repeatedly n times or forever if none or +nil+ is given. If a non-positive number is given or the collection is empty, does nothing. Returns +nil+ if the loop has finished without getting interrupted.

Enumerable#cycle saves elements in an internal array so changes to enum after the first pass have no effect.

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

a = ["a", "b", "c"]
a.cycle { |x| puts x }  # print, a, b, c, a, b, c,.. forever.
a.cycle(2) { |x| puts x }  # print, a, b, c, a, b, c.



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 664

def cycle(nv = nil, &block)
  return to_enum(:cycle, nv) unless block

  n = nil

  if nv.nil?
    n = -1
  else
    n = nv.__to_int
    return nil if n <= 0
  end

  ary = []
  each do |*i|
    ary.push(i)
    yield(*i)
  end
  return nil if ary.empty?

  while n < 0 || 0 < (n -= 1)
    ary.each do |i|
      yield(*i)
    end
  end

  nil
end

#detect(ifnone = nil, &block) ⇒ Object Also known as: find

Return the first element for which value from the block is true. If no object matches, calls +ifnone+ and returns its result. Otherwise returns +nil+.

ISO 15.3.2.2.4



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# File 'mrblib/enum.rb', line 75

def detect(ifnone=nil, &block)
  return to_enum :detect, ifnone unless block

  self.each{|*val|
    if block.call(*val)
      return val.__svalue
    end
  }
  ifnone.call unless ifnone.nil?
end

#drop(n) ⇒ Object

call-seq: enum.drop(n) -> array

Drops first n elements from enum, and returns rest elements in an array.

a = [1, 2, 3, 4, 5, 0] a.drop(3) #=> [4, 5, 0]

Raises:



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 15

def drop(n)
  n = n.__to_int
  raise ArgumentError, "attempt to drop negative size" if n < 0

  ary = []
  self.each {|*val| n == 0 ? ary << val.__svalue : n -= 1 }
  ary
end

#drop_while(&block) ⇒ Object

call-seq: enum.drop_while {|arr| block } -> array enum.drop_while -> an_enumerator

Drops elements up to, but not including, the first element for which the block returns +nil+ or +false+ and returns an array containing the remaining elements.

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

a = [1, 2, 3, 4, 5, 0] a.drop_while {|i| i < 3 } #=> [3, 4, 5, 0]



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 38

def drop_while(&block)
  return to_enum :drop_while unless block

  ary, state = [], false
  self.each do |*val|
    state = true if !state and !block.call(*val)
    ary << val.__svalue if state
  end
  ary
end

#each_cons(n, &block) ⇒ nil

Iterates the given block for each array of consecutive elements.

Examples:

(1..10).each_cons(3) {|a| p a}
# outputs below
[1, 2, 3]
[2, 3, 4]
[3, 4, 5]
[4, 5, 6]
[5, 6, 7]
[6, 7, 8]
[7, 8, 9]
[8, 9, 10]

Returns:

  • (nil)

Raises:



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 114

def each_cons(n, &block)
  n = n.__to_int
  raise ArgumentError, "invalid size" if n <= 0

  return to_enum(:each_cons,n) unless block
  ary = []
  n = n.to_i
  self.each do |*val|
    ary.shift if ary.size == n
    ary << val.__svalue
    block.call(ary.dup) if ary.size == n
  end
  nil
end

#each_slice(n, &block) ⇒ nil

Iterates the given block for each slice of elements.

Examples:

(1..10).each_slice(3) {|a| p a}
# outputs below
[1, 2, 3]
[4, 5, 6]
[7, 8, 9]
[10]

Returns:

  • (nil)

Raises:



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 142

def each_slice(n, &block)
  n = n.__to_int
  raise ArgumentError, "invalid slice size" if n <= 0

  return to_enum(:each_slice,n) unless block
  ary = []
  n = n.to_i
  self.each do |*val|
    ary << val.__svalue
    if ary.size == n
      block.call(ary)
      ary = []
    end
  end
  block.call(ary) unless ary.empty?
  nil
end

#each_with_index(&block) ⇒ Object

Call the given block for each element which is yield by +each+. Pass an index to the block which starts at 0 and increase by 1 for each element.

ISO 15.3.2.2.5



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# File 'mrblib/enum.rb', line 93

def each_with_index(&block)
  return to_enum :each_with_index unless block

  i = 0
  self.each{|*val|
    block.call(val.__svalue, i)
    i += 1
  }
  self
end

#each_with_object(obj, &block) ⇒ Object

call-seq: enum.each_with_object(obj) { |(*args), memo_obj| … } -> obj enum.each_with_object(obj) -> an_enumerator

Iterates the given block for each element with an arbitrary object given, and returns the initially given object.

If no block is given, returns an enumerator.

(1..10).each_with_object([]) { |i, a| a << i*2 }
#=> [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 607

def each_with_object(obj, &block)
  return to_enum(:each_with_object, obj) unless block

  self.each {|*val| block.call(val.__svalue, obj) }
  obj
end

#entries ⇒ Object Also known as: to_a

Return an array of all elements which are yield by +each+.

ISO 15.3.2.2.6



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# File 'mrblib/enum.rb', line 109

def entries
  ary = []
  self.each{|*val|
    # __svalue is an internal method
    ary.push val.__svalue
  }
  ary
end

#filter_map(&blk) ⇒ Object 



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 830

def filter_map(&blk)
  return to_enum(:filter_map) unless blk

  ary = []
  self.each do |x|
    x = blk.call(x)
    ary.push x if x
  end
  ary
end

#find_all(&block) ⇒ Object Also known as: select

Call the given block for each element which is yield by +each+. Return an array which contains all elements whose block value was true.

ISO 15.3.2.2.8



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# File 'mrblib/enum.rb', line 131

def find_all(&block)
  return to_enum :find_all unless block

  ary = []
  self.each{|*val|
    ary.push(val.__svalue) if block.call(*val)
  }
  ary
end

#find_index(val = NONE, &block) ⇒ Object

call-seq: enum.find_index(value) -> int or nil enum.find_index { |obj| block } -> int or nil enum.find_index -> an_enumerator

Compares each entry in enum with value or passes to block. Returns the index for the first for which the evaluated value is non-false. If no object matches, returns nil

If neither block nor argument is given, an enumerator is returned instead.

(1..10).find_index  { |i| i % 5 == 0 and i % 7 == 0 }  #=> nil
(1..100).find_index { |i| i % 5 == 0 and i % 7 == 0 }  #=> 34
(1..100).find_index(50)                                #=> 49



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 710

def find_index(val=NONE, &block)
  return to_enum(:find_index, val) if !block && val == NONE

  idx = 0
  if block
    self.each do |*e|
      return idx if block.call(*e)
      idx += 1
    end
  else
    self.each do |*e|
      return idx if e.__svalue == val
      idx += 1
    end
  end
  nil
end

#first(*args) ⇒ Object

call-seq: enum.first -> obj or nil enum.first(n) -> an_array

Returns the first element, or the first +n+ elements, of the enumerable. If the enumerable is empty, the first form returns nil, and the second form returns an empty array.



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 216

def first(*args)
  case args.length
  when 0
    self.each do |*val|
      return val.__svalue
    end
    return nil
  when 1
    i = args[0].__to_int
    raise ArgumentError, "attempt to take negative size" if i < 0
    ary = []
    return ary if i == 0
    self.each do |*val|
      ary << val.__svalue
      i -= 1
      break if i == 0
    end
    ary
  else
    raise ArgumentError, "wrong number of arguments (given #{args.length}, expected 0..1)"
  end
end

#flat_map(&block) ⇒ Object Also known as: collect_concat

call-seq: enum.flat_map { |obj| block } -> array enum.collect_concat { |obj| block } -> array enum.flat_map -> an_enumerator enum.collect_concat -> an_enumerator

Returns a new array with the concatenated results of running block once for every element in enum.

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

[1, 2, 3, 4].flat_map { e [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4]
[[1, 2], [3, 4]].flat_map { e e + [100] } #=> [1, 2, 100, 3, 4, 100] 


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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 281

def flat_map(&block)
  return to_enum :flat_map unless block

  ary = []
  self.each do |*e|
    e2 = block.call(*e)
    if e2.respond_to? :each
      e2.each {|e3| ary.push(e3) }
    else
      ary.push(e2)
    end
  end
  ary
end

#grep(pattern, &block) ⇒ Object

Call the given block for each element which is yield by +each+ and which return value was true when invoking === with +pattern+. Return an array with all elements or the respective block values.

ISO 15.3.2.2.9



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# File 'mrblib/enum.rb', line 149

def grep(pattern, &block)
  ary = []
  self.each{|*val|
    sv = val.__svalue
    if pattern === sv
      ary.push((block)? block.call(*val): sv)
    end
  }
  ary
end

#group_by(&block) ⇒ Object

call-seq: enum.group_by {| obj | block } -> a_hash enum.group_by -> an_enumerator

Returns a hash, which keys are evaluated result from the block, and values are arrays of elements in enum corresponding to the key.

(1..6).group_by {|i| i%3}   #=> {0=>[3, 6], 1=>[1, 4], 2=>[2, 5]}



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 171

def group_by(&block)
  return to_enum :group_by unless block

  h = {}
  self.each do |*val|
    key = block.call(*val)
    sv = val.__svalue
    h.key?(key) ? (h[key] << sv) : (h[key] = [sv])
  end
  h
end

#hash ⇒ Object

redefine #hash 15.3.1.3.15



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# File 'mrblib/enum.rb', line 344

def hash
  h = 12347
  i = 0
  self.each do |e|
    h = __update_hash(h, i, e.hash)
    i += 1
  end
  h
end

#include?(obj) ⇒ Boolean Also known as: member?

Return true if at least one element which is yield by +each+ returns a true value by invoking == with +obj+. Otherwise return false.

ISO 15.3.2.2.10

Returns:

  • (Boolean) 


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# File 'mrblib/enum.rb', line 167

def include?(obj)
  self.each{|*val|
    return true if val.__svalue == obj
  }
  false
end

#inject(*args, &block) ⇒ Object Also known as: reduce

Call the given block for each element which is yield by +each+. Return value is the sum of all block values. Pass to each block the current sum and the current element.

ISO 15.3.2.2.11

Raises:



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# File 'mrblib/enum.rb', line 182

def inject(*args, &block)
  raise ArgumentError, "too many arguments" if args.size > 2
  if Symbol === args[-1]
    sym = args[-1]
    block = ->(x,y){x.__send__(sym,y)}
    args.pop
  end
  if args.empty?
    flag = true  # no initial argument
    result = nil
  else
    flag = false
    result = args[0]
  end
  self.each{|*val|
    val = val.__svalue
    if flag
      # push first element as initial
      flag = false
      result = val
    else
      result = block.call(result, val)
    end
  }
  result
end

#lazy ⇒ Object

= Enumerable#lazy implementation

Enumerable#lazy returns an instance of Enumerator::Lazy. You can use it just like as normal Enumerable object, except these methods act as ‘lazy’:

  • map collect
  • select find_all
  • reject
  • grep
  • drop
  • drop_while
  • take_while
  • flat_map collect_concat
  • zip


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# File 'mrbgems/mruby-enum-lazy/mrblib/lazy.rb', line 18

def lazy
  Enumerator::Lazy.new(self)
end

#max(&block) ⇒ Object

Return the maximum value of all elements yield by +each+. If no block is given <=> will be invoked to define this value. If a block is given it will be used instead.

ISO 15.3.2.2.13



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# File 'mrblib/enum.rb', line 223

def max(&block)
  flag = true  # 1st element?
  result = nil
  self.each{|*val|
    val = val.__svalue
    if flag
      # 1st element
      result = val
      flag = false
    else
      if block
        result = val if block.call(val, result) > 0
      else
        result = val if (val <=> result) > 0
      end
    end
  }
  result
end

#max_by(&block) ⇒ Object

call-seq: enum.max_by {|obj| block } -> obj enum.max_by -> an_enumerator

Returns the object in enum that gives the maximum value from the given block.

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

%w[albatross dog horse].max_by { x x.length } #=> “albatross” 


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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 309

def max_by(&block)
  return to_enum :max_by unless block

  first = true
  max = nil
  max_cmp = nil

  self.each do |*val|
    if first
      max = val.__svalue
      max_cmp = block.call(*val)
      first = false
    else
      if (cmp = block.call(*val)) > max_cmp
        max = val.__svalue
        max_cmp = cmp
      end
    end
  end
  max
end

#min(&block) ⇒ Object

Return the minimum value of all elements yield by +each+. If no block is given <=> will be invoked to define this value. If a block is given it will be used instead.

ISO 15.3.2.2.14



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# File 'mrblib/enum.rb', line 250

def min(&block)
  flag = true  # 1st element?
  result = nil
  self.each{|*val|
    val = val.__svalue
    if flag
      # 1st element
      result = val
      flag = false
    else
      if block
        result = val if block.call(val, result) < 0
      else
        result = val if (val <=> result) < 0
      end
    end
  }
  result
end

#min_by(&block) ⇒ Object

call-seq: enum.min_by {|obj| block } -> obj enum.min_by -> an_enumerator

Returns the object in enum that gives the minimum value from the given block.

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

%w[albatross dog horse].min_by { x x.length } #=> “dog” 


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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 343

def min_by(&block)
  return to_enum :min_by unless block

  first = true
  min = nil
  min_cmp = nil

  self.each do |*val|
    if first
      min = val.__svalue
      min_cmp = block.call(*val)
      first = false
    else
      if (cmp = block.call(*val)) < min_cmp
        min = val.__svalue
        min_cmp = cmp
      end
    end
  end
  min
end

#minmax(&block) ⇒ Object

call-seq: enum.minmax -> [min, max] enum.minmax { |a, b| block } -> [min, max]

Returns two elements array which contains the minimum and the maximum value in the enumerable. The first form assumes all objects implement Comparable; the second uses the block to return a <=> b.

a = %w(albatross dog horse)
a.minmax                                  #=> ["albatross", "horse"]
a.minmax { |a, b| a.length <=> b.length } #=> ["dog", "albatross"]



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 379

def minmax(&block)
  max = nil
  min = nil
  first = true

  self.each do |*val|
    if first
      val = val.__svalue
      max = val
      min = val
      first = false
    else
      val = val.__svalue
      if block
        max = val if block.call(val, max) > 0
        min = val if block.call(val, min) < 0
      else
        max = val if (val <=> max) > 0
        min = val if (val <=> min) < 0
      end
    end
  end
  [min, max]
end

#minmax_by(&block) ⇒ Object

call-seq: enum.minmax_by { |obj| block } -> [min, max] enum.minmax_by -> an_enumerator

Returns a two element array containing the objects in enum that correspond to the minimum and maximum values respectively from the given block.

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

%w(albatross dog horse).minmax_by { |x| x.length }   #=> ["dog", "albatross"]



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 417

def minmax_by(&block)
  return to_enum :minmax_by unless block

  max = nil
  max_cmp = nil
  min = nil
  min_cmp = nil
  first = true

  self.each do |*val|
    if first
      max = min = val.__svalue
      max_cmp = min_cmp = block.call(*val)
      first = false
   else
      if (cmp = block.call(*val)) > max_cmp
        max = val.__svalue
        max_cmp = cmp
      end
      if (cmp = block.call(*val)) < min_cmp
        min = val.__svalue
        min_cmp = cmp
      end
    end
  end
  [min, max]
end

#none?(pat = NONE, &block) ⇒ Boolean

call-seq: enum.none? [{ |obj| block }] -> true or false enum.none?(pattern) -> true or false

Passes each element of the collection to the given block. The method returns true if the block never returns true for all elements. If the block is not given, none? will return true only if none of the collection members is true.

If a pattern is supplied instead, the method returns whether pattern === element for none of the collection members.

%w(ant bear cat).none? { |word| word.length == 5 } #=> true
%w(ant bear cat).none? { |word| word.length >= 4 } #=> false
%w{ant bear cat}.none?(/d/)                        #=> true
[1, 3.14, 42].none?(Float)                         #=> false
[].none?                                           #=> true
[nil, false].none?                                 #=> true
[nil, true].none?                                  #=> false

Returns:

  • (Boolean) 


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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 466

def none?(pat=NONE, &block)
  if pat != NONE
    self.each do |*val|
      return false if pat === val.__svalue
    end
  elsif block
    self.each do |*val|
      return false if block.call(*val)
    end
  else
    self.each do |*val|
      return false if val.__svalue
    end
  end
  true
end

#one?(pat = NONE, &block) ⇒ Boolean

call-seq: enum.one? [{ |obj| block }] -> true or false enum.one?(pattern) -> true or false

Passes each element of the collection to the given block. The method returns true if the block returns true exactly once. If the block is not given, one? will return true only if exactly one of the collection members is true.

If a pattern is supplied instead, the method returns whether pattern === element for exactly one collection member.

%w(ant bear cat).one? { |word| word.length == 4 } #=> true %w(ant bear cat).one? { |word| word.length > 4 } #=> false %w(ant bear cat).one? { |word| word.length < 4 } #=> false %wbear cat.one?(/t/) #=> false [nil, true, 99].one? #=> false [nil, true, false].one? #=> true [ nil, true, 99 ].one?(Integer) #=> true [].one? #=> false

Returns:

  • (Boolean) 


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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 506

def one?(pat=NONE, &block)
  count = 0
  if pat!=NONE
    self.each do |*val|
      count += 1 if pat === val.__svalue
      return false if count > 1
    end
  elsif block
    self.each do |*val|
      count += 1 if block.call(*val)
      return false if count > 1
    end
  else
    self.each do |*val|
      count += 1 if val.__svalue
      return false if count > 1
    end
  end

  count == 1 ? true : false
end

#partition(&block) ⇒ Object

Call the given block for each element which is yield by +each+. Return an array which contains two arrays. The first array contains all elements whose block value was true. The second array contains all elements whose block value was false.

ISO 15.3.2.2.16



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# File 'mrblib/enum.rb', line 286

def partition(&block)
  return to_enum :partition unless block

  ary_T = []
  ary_F = []
  self.each{|*val|
    if block.call(*val)
      ary_T.push(val.__svalue)
    else
      ary_F.push(val.__svalue)
    end
  }
  [ary_T, ary_F]
end

#reject(&block) ⇒ Object

Call the given block for each element which is yield by +each+. Return an array which contains only the elements whose block value was false.

ISO 15.3.2.2.17



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# File 'mrblib/enum.rb', line 308

def reject(&block)
  return to_enum :reject unless block

  ary = []
  self.each{|*val|
    ary.push(val.__svalue) unless block.call(*val)
  }
  ary
end

#reverse_each(&block) ⇒ Object

call-seq: enum.reverse_each { |item| block } -> enum enum.reverse_each -> an_enumerator

Builds a temporary array and traverses that array in reverse order.

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

 (1..3).reverse_each { |v| p v }

produces:

 3
 2
 1



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 632

def reverse_each(&block)
  return to_enum :reverse_each unless block

  ary = self.to_a
  i = ary.size - 1
  while i>=0
    block.call(ary[i])
    i -= 1
  end
  self
end

#sort(&block) ⇒ Object

Return a sorted array of all elements which are yield by +each+. If no block is given <=> will be invoked on each element to define the order. Otherwise the given block will be used for sorting.

ISO 15.3.2.2.19



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# File 'mrblib/enum.rb', line 333

def sort(&block)
  self.map{|*val| val.__svalue}.sort(&block)
end

#sort_by(&block) ⇒ Object

call-seq: enum.sort_by { |obj| block } -> array enum.sort_by -> an_enumerator

Sorts enum using a set of keys generated by mapping the values in enum through the given block.

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



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 193

def sort_by(&block)
  return to_enum :sort_by unless block

  ary = []
  orig = []
  self.each_with_index{|e, i|
    orig.push(e)
    ary.push([block.call(e), i])
  }
  if ary.size > 1
    ary.sort!
  end
  ary.collect{|e,i| orig[i]}
end

#take(n) ⇒ Object

call-seq: enum.take(n) -> array

Returns first n elements from enum.

a = [1, 2, 3, 4, 5, 0] a.take(3) #=> [1, 2, 3]

Raises:



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 58

def take(n)
  n = n.__to_int
  i = n.to_i
  raise ArgumentError, "attempt to take negative size" if i < 0
  ary = []
  return ary if i == 0
  self.each do |*val|
    ary << val.__svalue
    i -= 1
    break if i == 0
  end
  ary
end

#take_while(&block) ⇒ Object

call-seq: enum.take_while {|arr| block } -> array enum.take_while -> an_enumerator

Passes elements to the block until the block returns +nil+ or +false+, then stops iterating and returns an array of all prior elements.

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

a = [1, 2, 3, 4, 5, 0]
a.take_while {|i| i < 3 }   #=> [1, 2]



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 85

def take_while(&block)
  return to_enum :take_while unless block

  ary = []
  self.each do |*val|
    return ary unless block.call(*val)
    ary << val.__svalue
  end
  ary
end

#tally ⇒ Object

call-seq: enum.tally -> a_hash

Tallys the collection. Returns a hash where the keys are the elements and the values are numbers of elements in the collection that correspond to the key.

[“a”, “b”, “c”, “b”].tally #=> “b”=>2, “c”=>1



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 852

def tally
  hash = {}
  self.each do |x|
    hash[x] = (hash[x]||0)+1
  end
  hash
end

#to_h(&blk) ⇒ Object

call-seq: enum.to_h -> hash

Returns the result of interpreting enum as a list of [key, value] pairs.

%i[hello world].each_with_index.to_h
  # => {:hello => 0, :world => 1}



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 794

def to_h(&blk)
  h = {}
  if blk
    self.each do |v|
      v = blk.call(v)
      raise TypeError, "wrong element type #{v.class} (expected Array)" unless v.is_a? Array
      raise ArgumentError, "element has wrong array length (expected 2, was #{v.size})" if v.size != 2
      h[v[0]] = v[1]
    end
  else
    self.each do |*v|
      v = v.__svalue
      raise TypeError, "wrong element type #{v.class} (expected Array)" unless v.is_a? Array
      raise ArgumentError, "element has wrong array length (expected 2, was #{v.size})" if v.size != 2
      h[v[0]] = v[1]
    end
  end
  h
end

#uniq(&block) ⇒ Object 



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 814

def uniq(&block)
  hash = {}
  if block
    self.each do|*v|
      v = v.__svalue
      hash[block.call(v)] ||= v
    end
  else
    self.each do|*v|
      v = v.__svalue
      hash[v] ||= v
    end
  end
  hash.values
end

#zip(*args, &block) ⇒ Object

use Enumerator to use infinite sequence



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# File 'mrbgems/mruby-enum-ext/mrblib/enum.rb', line 755

def zip(*arg, &block)
  result = block ? nil : []
  arg = arg.map do |a|
    unless a.respond_to?(:to_a)
      raise TypeError, "wrong argument type #{a.class} (must respond to :to_a)"
    end
    a.to_a
  end

  i = 0
  self.each do |*val|
    a = []
    a.push(val.__svalue)
    idx = 0
    while idx < arg.size
      a.push(arg[idx][i])
      idx += 1
    end
    i += 1
    if result.nil?
      block.call(a)
    else
      result.push(a)
    end
  end
  result
end