Module: Enumerable

Defined in:
lib/mug/top.rb,
lib/mug/bool.rb,
lib/mug/enumerable/counts.rb,
lib/mug/enumerable/hash-like.rb,
lib/mug/enumerable/any-and-all.rb

Instance Method Summary collapse

Instance Method Details

#any_and_all?(&block) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/mug/enumerable/any-and-all.rb', line 10

def any_and_all? &block
  block ||= proc {|obj| obj }

  result = false
  each do |x|
    return false unless block[x]
    result = true
  end
  result
end

#bottom(n = 1, &blk) ⇒ Object

Get the bottom n items, ordered from bottom to top.

Returns an Array even when n is 1.

See Also:

  • #sort


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# File 'lib/mug/top.rb', line 58

def bottom n=1, &blk
  if block_given?
    sort(&blk)[0...n]
  else
    #bottom_by(n) {|x| x }
    sort[0...n]
  end
end

#bottom_by(n = 1, &blk) ⇒ Object

Get the bottom n items, in order from bottom to top, ordered by mapping the values through the given block.

Returns an Array even when n is 1. Values that are tied after mapping are returned in the initial order.

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

See Also:

  • #sort_by


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# File 'lib/mug/top.rb', line 78

def bottom_by n=1, &blk
  return enum_for(:bottom_by, n) unless block_given?
  chain = {}
  each do |x|
    y = yield x
    chain[y] ||= []
    chain[y] << x
  end
  ary = []
  chain.keys.sort.each do |k|
    ary += chain[k]
    break if ary.length > n
  end
  ary[0...n]
end

#counts(&block) ⇒ Object

Returns a hash of item=>count showing how many of each item are in this Enumerable.



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# File 'lib/mug/enumerable/counts.rb', line 8

def counts &block
  return counts_by(&block) if block_given?
  hsh = Hash.new{|h,k| h[k] = 0 }
  each do |k|
    hsh[k] += 1
  end
  hsh
end

#counts_by(&block) ⇒ Object

Passes each element in turn to the block, and returns a hash of result=>count.

If no block is given, an enumerator is returned.



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# File 'lib/mug/enumerable/counts.rb', line 23

def counts_by &block
  return enum_for(:counts_by) unless block_given?
  hsh = Hash.new{|h,k| h[k] = 0 }
  each do |j|
    k = yield j
    hsh[k] += 1
  end
  hsh
end

#each_key ⇒ Object

Calls block once for each key in the enum, passing the key as a parameter. If no block is given, an enumerator is returned instead.

@call-seq each_key {| key | block } -> hsh @call-seq each_key -> an_enumerator



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# File 'lib/mug/enumerable/hash-like.rb', line 23

def each_key
  return enum_for(:each_key) unless block_given?

  # FIXME
  each_with_index {|_,i| yield i }
end

#each_pair ⇒ Object

Calls block once for each key in the enum, passing the key-value pair as parameters. If no block is given, an enumerator is returned instead.

@call-seq each_pair {| key, value | block } -> hsh @call-seq each_pair -> an_enumerator



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# File 'lib/mug/enumerable/hash-like.rb', line 11

def each_pair
  return enum_for(:each_pair) unless block_given?
  each_with_index {|e,i| yield i, e }
end

#fetch(*args) ⇒ Object

Returns a value from the enum for the given key. If the key can’t be found, there are several options: With no other arguments, it will raise a KeyError exception; if default is given, then that will be returned; if the optional code block is specified, then that will be run and its result returned.

@call-seq fetch(key [, default] ) -> obj @call-seq fetch(key) { |key| block } -> obj

Raises:

  • (ArgumentError) 


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# File 'lib/mug/enumerable/hash-like.rb', line 42

def fetch *args
  raise ArgumentError, "incorrect number of arguments (#{args.length} for 1..2)" if args.length < 1 || args.length > 2
  key, default = *args

  each_pair do |k,v|
    return v if k == key
  end
  if args.length > 1
    return default
  elsif block_given?
    yield key
  else
    raise KeyError, 'key not found'
  end
end

#fetch_values(*keys) ⇒ Object

Returns an array containing the values associated with the given keys but also raises KeyError when one of keys can’t be found. Also see #values_at and #fetch.

@call-seq fetch_values(key, …) -> array @call-seq fetch_values(key, …) { |key| block } -> array



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# File 'lib/mug/enumerable/hash-like.rb', line 66

def fetch_values *keys
  key_map = {}
  keys.each_with_index do |key, index|
    key_map[key] ||= []
    key_map[key] << index
  end

  remain = keys.length
  result = [nil] * keys.length
  define = [nil] * keys.length

  each_pair do |k,v|
    break if remain < 1

    key_indices = key_map[k]
    if key_indices
      key_indices.each do |key_index|
        result[key_index] = v
        define[key_index] = true
        remain -= 1
      end
    end
  end

  if remain > 0
    if block_given?
      define.each_with_index do |isdef, index|
        next if isdef
        result[index] = yield keys[index]
      end
    else
      index = define.index nil
      raise KeyError, "key not found: #{keys[index].inspect}"
    end
  end

  result
end

#key?(key) ⇒ Boolean Also known as: has_key?

Returns true if the given key is present in this enum.

@call-seq key?(key) -> true or false

Returns:

  • (Boolean) 


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# File 'lib/mug/enumerable/hash-like.rb', line 112

def key? key
  each_pair.find {|k, _| key == k } && true
end

#keys ⇒ Object

Returns a new array populated with the keys from this enum.

@call-seq keys -> array



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# File 'lib/mug/enumerable/hash-like.rb', line 122

def keys
  each_with_index.map {|_, index| index }
end

#length ⇒ Object Also known as: size

Returns the number of key-value pairs in the hash.

@call-seq length -> integer



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# File 'lib/mug/enumerable/hash-like.rb', line 131

def length
  reduce(0) {|sum,_| sum + 1 }
end

#member?(key) ⇒ Boolean

Returns true if the given key is present in this enum.

@call-seq member?(key) -> true or false

Returns:

  • (Boolean) 


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# File 'lib/mug/enumerable/hash-like.rb', line 141

def member? key
  fetch(key, nil) && true
end

#slice(*keys) ⇒ Object

Returns a hash containing only the given keys and their values.

@call-seq slice(*keys) -> a_hash



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# File 'lib/mug/enumerable/hash-like.rb', line 150

def slice *keys
  missing = {}
  values = fetch_values(*keys) {|key| missing[key] = nil }

  result = {}
  values.each_with_index do |val, i|
    key = keys[i]
    next if missing.key? key
    next if result.key? key
    result[key] = val
  end
  result
end

#to_b ⇒ Object

Converts enum to a boolean. Returns true if there are any elements.



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# File 'lib/mug/bool.rb', line 86

def to_b
  any?{ true }
end

#top(n = 1, &blk) ⇒ Object

Get the top n items, in order from top to bottom.

Returns an Array even when n is 1.

See Also:

  • #sort


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# File 'lib/mug/top.rb', line 11

def top n=1, &blk
  if block_given?
    sort{|x,y| yield y, x }[0...n]
  else
    #top_by(n) {|x| x }
    if n <= length
      sort[-n..-1].reverse
    else
      sort.reverse
    end
  end
end

#top_by(n = 1, &blk) ⇒ Object

Get the top n items, in order from top to bottom, ordered by mapping the values through the given block.

Returns an Array even when n is 1. Values that are tied after mapping are returned in the initial order.

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

See Also:

  • #sort_by


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# File 'lib/mug/top.rb', line 35

def top_by n=1, &blk
  return enum_for(:top_by, n) unless block_given?
  chain = {}
  each do |x|
    y = yield x
    chain[y] ||= []
    chain[y] << x
  end
  ary = []
  chain.keys.sort.reverse.each do |k|
    ary += chain[k]
    break if ary.length > n
  end
  ary[0...n]
end

#transform_keys ⇒ Object

Returns a new hash with the results of running the block once for every key. If no block is given, an enumerator is returned instead.

@call-seq transform_keys {|key| block } -> new_hash @call-seq transform_keys -> an_enumerator



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# File 'lib/mug/enumerable/hash-like.rb', line 171

def transform_keys
  return enum_for(:transform_keys) unless block_given?
  result = {}
  each_pair do |key, value|
    newkey = yield key
    result[newkey] = value
  end
  result
end

#transform_values ⇒ Object

Returns a new hash with the results of running the block once for every value. If no block is given, an enumerator is returned instead.

@call-seq transform_values {|value| block } -> new_hash @call-seq transform_values -> an_enumerator



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# File 'lib/mug/enumerable/hash-like.rb', line 188

def transform_values
  return enum_for(:transform_values) unless block_given?
  result = {}
  each_pair do |key, value|
    newvalue = yield value
    result[key] = newvalue
  end
  result
end

#value?(value) ⇒ Boolean Also known as: has_value?

Returns true if the given value is present for some key.

@call-seq value?(value) -> true or false

Returns:

  • (Boolean) 


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# File 'lib/mug/enumerable/hash-like.rb', line 203

def value? value
  include? value
end

#values ⇒ Object

Returns a new array populated with the values from this enum.

@call-seq values -> array



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# File 'lib/mug/enumerable/hash-like.rb', line 213

def values
  to_a
end

#values_at(*keys) ⇒ Object

Return an array containing the values associated with the given keys.

@call-seq values_at(key, …) -> array



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# File 'lib/mug/enumerable/hash-like.rb', line 222

def values_at *keys
  fetch_values(*keys) {|key| nil }
end