Files
mruby-mruby/mrbgems/mruby-array-ext/mrblib/array.rb
T
Yukihiro "Matz" Matsumoto 90fd382a9e mruby-array-ext: implement Array#fetch with hybrid approach
Moved Array#fetch from Ruby to C using hybrid implementation for
better performance. The C implementation handles all non-block cases
with unified API that eliminates Ruby conditional logic.

Key improvements:
- Fast C implementation for common cases (no blocks)
- Shared index normalization helper reusable for other methods
- Unified C call eliminates NONE sentinel comparison in Ruby
- Block cases use C helper for index normalization

Added comprehensive test coverage including edge cases, default values,
block handling, and error message format verification. Combined tests
to focus on functionality rather than implementation details.

Co-authored-by: Atlassian Rovo Dev
2025-06-30 12:17:21 +09:00

724 lines
19 KiB
Ruby

class Array
##
# call-seq:
# ary.uniq! -> ary or nil
# ary.uniq! { |item| ... } -> ary or nil
#
# Removes duplicate elements from +self+.
# Returns <code>nil</code> if no changes are made (that is, no
# duplicates are found).
#
# a = [ "a", "a", "b", "b", "c" ]
# a.uniq! #=> ["a", "b", "c"]
# b = [ "a", "b", "c" ]
# b.uniq! #=> nil
# c = [["student","sam"], ["student","george"], ["teacher","matz"]]
# c.uniq! { |s| s.first } # => [["student", "sam"], ["teacher", "matz"]]
#
def uniq!(&block)
if block
hash = {}
result = []
self.each do |val|
key = block.call(val)
unless hash.key?(key)
hash[key] = true
result << val
end
end
if result.size == self.size
nil
else
self.replace(result)
end
else
__uniq!
end
end
##
# call-seq:
# ary.uniq -> new_ary
# ary.uniq { |item| ... } -> new_ary
#
# Returns a new array by removing duplicate values in +self+.
#
# a = [ "a", "a", "b", "b", "c" ]
# a.uniq #=> ["a", "b", "c"]
#
# b = [["student","sam"], ["student","george"], ["teacher","matz"]]
# b.uniq { |s| s.first } # => [["student", "sam"], ["teacher", "matz"]]
#
def uniq(&block)
if block
ary = self.dup
ary.uniq!(&block)
ary
else
__uniq
end
end
# for efficiency
def reverse_each(&block)
return to_enum :reverse_each unless block
i = self.size - 1
while i>=0
block.call(self[i])
i -= 1
end
self
end
##
# call-seq:
# ary.fetch(index) -> obj
# ary.fetch(index, default) -> obj
# ary.fetch(index) { |index| block } -> obj
#
# Tries to return the element at position +index+, but throws an IndexError
# exception if the referenced +index+ lies outside of the array bounds. This
# error can be prevented by supplying a second argument, which will act as a
# +default+ value.
#
# Alternatively, if a block is given it will only be executed when an
# invalid +index+ is referenced.
#
# Negative values of +index+ count from the end of the array.
#
# a = [ 11, 22, 33, 44 ]
# a.fetch(1) #=> 22
# a.fetch(-1) #=> 44
# a.fetch(4, 'cat') #=> "cat"
# a.fetch(100) { |i| puts "#{i} is out of bounds" }
# #=> "100 is out of bounds"
#
def fetch(n, ifnone=NONE, &block)
#warn "block supersedes default value argument" if !n.nil? && ifnone != NONE && block
if block
# Block case: use shared index helper + Ruby block handling
normalized_index = __normalize_index(n)
if normalized_index
self[normalized_index]
else
block.call(n)
end
else
# Fast C implementation for non-block cases
__fetch(n, ifnone, NONE)
end
end
##
# call-seq:
# ary.fill(obj) -> ary
# ary.fill(obj, start [, length]) -> ary
# ary.fill(obj, range ) -> ary
# ary.fill { |index| block } -> ary
# ary.fill(start [, length] ) { |index| block } -> ary
# ary.fill(range) { |index| block } -> ary
#
# The first three forms set the selected elements of +self+ (which
# may be the entire array) to +obj+.
#
# A +start+ of +nil+ is equivalent to zero.
#
# A +length+ of +nil+ is equivalent to the length of the array.
#
# The last three forms fill the array with the value of the given block,
# which is passed the absolute index of each element to be filled.
#
# Negative values of +start+ count from the end of the array, where +-1+ is
# the last element.
#
# a = [ "a", "b", "c", "d" ]
# a.fill("x") #=> ["x", "x", "x", "x"]
# a.fill("w", -1) #=> ["x", "x", "x", "w"]
# a.fill("z", 2, 2) #=> ["x", "x", "z", "z"]
# a.fill("y", 0..1) #=> ["y", "y", "z", "z"]
# a.fill { |i| i*i } #=> [0, 1, 4, 9]
# a.fill(-2) { |i| i*i*i } #=> [0, 1, 8, 27]
# a.fill(1, 2) { |i| i+1 } #=> [0, 2, 3, 27]
# a.fill(0..1) { |i| i+1 } #=> [1, 2, 3, 27]
#
def fill(arg0=nil, arg1=nil, arg2=nil, &block)
if arg0.nil? && arg1.nil? && arg2.nil? && !block
raise ArgumentError, "wrong number of arguments (given 0, expected 1..3)"
end
# Use shared C argument parser for all cases
start, length = __fill_parse_arg(arg0, arg1, arg2, &block)
if block
# Block-based filling in Ruby
i = start
while i < start + length
self[i] = block.call(i)
i += 1
end
else
# Use fast C implementation for value filling
__fill_exec(start, length, arg0)
end
self
end
##
# call-seq:
# ary.delete_if { |item| block } -> ary
# ary.delete_if -> Enumerator
#
# Deletes every element of +self+ for which block evaluates to +true+.
#
# The array is changed instantly every time the block is called, not after
# the iteration is over.
#
# See also Array#reject!
#
# If no block is given, an Enumerator is returned instead.
#
# scores = [ 97, 42, 75 ]
# scores.delete_if {|score| score < 80 } #=> [97]
def delete_if(&block)
return to_enum :delete_if unless block
result = []
idx = 0
len = size
while idx < len
elem = self[idx]
result << elem unless block.call(elem)
idx += 1
end
self.replace(result)
end
##
# call-seq:
# ary.reject! { |item| block } -> ary or nil
# ary.reject! -> Enumerator
#
# Equivalent to Array#delete_if, deleting elements from +self+ for which the
# block evaluates to +true+, but returns +nil+ if no changes were made.
#
# The array is changed instantly every time the block is called, not after
# the iteration is over.
#
# See also Enumerable#reject and Array#delete_if.
#
# If no block is given, an Enumerator is returned instead.
def reject!(&block)
return to_enum :reject! unless block
result = []
idx = 0
len = size
while idx < len
elem = self[idx]
result << elem unless block.call(elem)
idx += 1
end
return nil if len == result.size
self.replace(result)
end
##
# call-seq:
# ary.bsearch {|x| block } -> elem
#
# By using binary search, finds a value from this array which meets
# the given condition in O(log n) where n is the size of the array.
#
# You can use this method in two use cases: a find-minimum mode and
# a find-any mode. In either case, the elements of the array must be
# monotone (or sorted) with respect to the block.
#
# In find-minimum mode (this is a good choice for typical use case),
# the block must return true or false, and there must be an index i
# (0 <= i <= ary.size) so that:
#
# - the block returns false for any element whose index is less than
# i, and
# - the block returns true for any element whose index is greater
# than or equal to i.
#
# This method returns the i-th element. If i is equal to ary.size,
# it returns nil.
#
# ary = [0, 4, 7, 10, 12]
# ary.bsearch {|x| x >= 4 } #=> 4
# ary.bsearch {|x| x >= 6 } #=> 7
# ary.bsearch {|x| x >= -1 } #=> 0
# ary.bsearch {|x| x >= 100 } #=> nil
#
# In find-any mode (this behaves like libc's bsearch(3)), the block
# must return a number, and there must be two indices i and j
# (0 <= i <= j <= ary.size) so that:
#
# - the block returns a positive number for ary[k] if 0 <= k < i,
# - the block returns zero for ary[k] if i <= k < j, and
# - the block returns a negative number for ary[k] if
# j <= k < ary.size.
#
# Under this condition, this method returns any element whose index
# is within i...j. If i is equal to j (i.e., there is no element
# that satisfies the block), this method returns nil.
#
# ary = [0, 4, 7, 10, 12]
# # try to find v such that 4 <= v < 8
# ary.bsearch {|x| 1 - (x / 4).truncate } #=> 4 or 7
# # try to find v such that 8 <= v < 10
# ary.bsearch {|x| 4 - (x / 2).truncate } #=> nil
#
# You must not mix the two modes at a time; the block must always
# return either true/false, or always return a number. It is
# undefined which value is actually picked up at each iteration.
def bsearch(&block)
return to_enum :bsearch unless block
if idx = bsearch_index(&block)
self[idx]
else
nil
end
end
##
# call-seq:
# ary.bsearch_index {|x| block } -> int or nil
#
# By using binary search, finds an index of a value from this array which
# meets the given condition in O(log n) where n is the size of the array.
#
# It supports two modes, depending on the nature of the block and they are
# exactly the same as in the case of #bsearch method with the only difference
# being that this method returns the index of the element instead of the
# element itself. For more details consult the documentation for #bsearch.
def bsearch_index(&block)
return to_enum :bsearch_index unless block
low = 0
high = size
satisfied = false
while low < high
mid = ((low+high)/2).truncate
res = block.call self[mid]
case res
when 0 # find-any mode: Found!
return mid
when Numeric # find-any mode: Continue...
in_lower_half = res < 0
when true # find-min mode
in_lower_half = true
satisfied = true
when false, nil # find-min mode
in_lower_half = false
else
raise TypeError, 'invalid block result (must be numeric, true, false or nil)'
end
if in_lower_half
high = mid
else
low = mid + 1
end
end
satisfied ? low : nil
end
##
# call-seq:
# ary.keep_if { |item| block } -> ary
# ary.keep_if -> Enumerator
#
# Deletes every element of +self+ for which the given block evaluates to
# +false+.
#
# See also Array#select!
#
# If no block is given, an Enumerator is returned instead.
#
# a = [1, 2, 3, 4, 5]
# a.keep_if { |val| val > 3 } #=> [4, 5]
def keep_if(&block)
return to_enum :keep_if unless block
result = []
idx = 0
len = size
while idx < len
elem = self[idx]
result << elem if block.call(elem)
idx += 1
end
self.replace(result)
end
##
# call-seq:
# ary.select! {|item| block } -> ary or nil
# ary.select! -> Enumerator
#
# Invokes the given block passing in successive elements from +self+,
# deleting elements for which the block returns a +false+ value.
#
# If changes were made, it will return +self+, otherwise it returns +nil+.
#
# See also Array#keep_if
#
# If no block is given, an Enumerator is returned instead.
def select!(&block)
return to_enum :select! unless block
result = []
idx = 0
len = size
while idx < len
elem = self[idx]
result << elem if block.call(elem)
idx += 1
end
return nil if len == result.size
self.replace(result)
end
##
# call-seq:
# ary.dig(idx, ...) -> object
#
# Extracts the nested value specified by the sequence of <i>idx</i>
# objects by calling +dig+ at each step, returning +nil+ if any
# intermediate step is +nil+.
#
def dig(idx,*args)
idx = idx.__to_int
n = self[idx]
if args.size > 0
n&.dig(*args)
else
n
end
end
##
# call-seq:
# ary.permutation { |p| block } -> ary
# ary.permutation -> Enumerator
# ary.permutation(n) { |p| block } -> ary
# ary.permutation(n) -> Enumerator
#
# When invoked with a block, yield all permutations of length +n+ of the
# elements of the array, then return the array itself.
#
# If +n+ is not specified, yield all permutations of all elements.
#
# The implementation makes no guarantees about the order in which the
# permutations are yielded.
#
# If no block is given, an Enumerator is returned instead.
#
# Examples:
#
# a = [1, 2, 3]
# a.permutation.to_a #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
# a.permutation(1).to_a #=> [[1],[2],[3]]
# a.permutation(2).to_a #=> [[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]]
# a.permutation(3).to_a #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
# a.permutation(0).to_a #=> [[]] # one permutation of length 0
# a.permutation(4).to_a #=> [] # no permutations of length 4
def permutation(n=self.size, &block)
n = n.__to_int
return to_enum(:permutation, n) unless block
size = self.size
if n == 0
yield []
elsif 0 < n && n <= size
i = 0
while i<size
result = [self[i]]
if n-1 > 0
ary = self[0...i] + self[i+1..-1]
ary.permutation(n-1) do |c|
yield result + c
end
else
yield result
end
i += 1
end
end
self
end
##
# call-seq:
# ary.combination(n) { |c| block } -> ary
# ary.combination(n) -> Enumerator
#
# When invoked with a block, yields all combinations of length +n+ of elements
# from the array and then returns the array itself.
#
# The implementation makes no guarantees about the order in which the
# combinations are yielded.
#
# If no block is given, an Enumerator is returned instead.
#
# Examples:
#
# a = [1, 2, 3, 4]
# a.combination(1).to_a #=> [[1],[2],[3],[4]]
# a.combination(2).to_a #=> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]
# a.combination(3).to_a #=> [[1,2,3],[1,2,4],[1,3,4],[2,3,4]]
# a.combination(4).to_a #=> [[1,2,3,4]]
# a.combination(0).to_a #=> [[]] # one combination of length 0
# a.combination(5).to_a #=> [] # no combinations of length 5
def combination(n, &block)
n = n.__to_int
return to_enum(:combination, n) unless block
size = self.size
if n == 0
yield []
elsif n == 1
i = 0
while i<size
yield [self[i]]
i += 1
end
elsif n <= size
i = 0
while i<size
result = [self[i]]
self[i+1..-1].combination(n-1) do |c|
yield result + c
end
i += 1
end
end
self
end
##
# call-seq:
# ary.transpose -> new_ary
#
# Assumes that self is an array of arrays and transposes the rows and columns.
#
# If the length of the subarrays don't match, an IndexError is raised.
#
# Examples:
#
# a = [[1,2], [3,4], [5,6]]
# a.transpose #=> [[1, 3, 5], [2, 4, 6]]
def transpose
return [] if empty?
column_count = nil
self.each do |row|
raise TypeError unless row.is_a?(Array)
column_count ||= row.size
raise IndexError, 'element size differs' unless column_count == row.size
end
Array.new(column_count) do |column_index|
self.map { |row| row[column_index] }
end
end
##
# call-seq:
# ary.to_h -> Hash
# ary.to_h{|item| ... } -> Hash
#
# Returns the result of interpreting <i>array</i> as an array of
# <tt>[key, value]</tt> pairs. If a block is given, it should
# return <tt>[key, value]</tt> pairs to construct a hash.
#
# [[:foo, :bar], [1, 2]].to_h
# # => {:foo => :bar, 1 => 2}
# [1, 2].to_h{|x| [x, x*2]}
# # => {1 => 2, 2 => 4}
#
def to_h(&blk)
h = {}
self.each do |v|
v = blk.call(v) if blk
raise TypeError, "wrong element type #{v.class}" unless Array === v
raise ArgumentError, "wrong array length (expected 2, was #{v.length})" unless v.length == 2
h[v[0]] = v[1]
end
h
end
alias append push
alias prepend unshift
alias filter! select!
##
# call-seq:
# ary.fetch_values(idx, ...) -> array
# ary.fetch_values(idx, ...) { |i| block } -> array
#
# Returns an array containing the values associated with the given indexes.
# but also raises <code>IndexError</code> when one of indexes can't be found.
# Also see <code>Array#values_at</code> and <code>Array#fetch</code>.
#
# a = ["cat", "dog", "cow"]
#
# a.fetch_values(2, 0) #=> ["cow", "cat"]
# a.fetch_values(2, 5) # raises KeyError
# a.fetch_values(2, 5) {|i| "BIRD" } #=> ["cow", "BIRD"]
#
def fetch_values(*idx, &block)
idx.map do |i|
self.fetch(i, &block)
end
end
##
# call-seq:
# ary.product(*arys) -> array
# ary.product(*arys) { |item| ... } -> self
def product(*arys, &block)
size = arys.size
i = size
while i > 0
i -= 1
unless arys[i].kind_of?(Array)
raise TypeError, "no implicit conversion into Array"
end
end
i = size
total = self.size
total *= arys[i -= 1].size while i > 0
if block
result = self
list = ->(*, e) { block.call e }
class << list; alias []= call; end
else
result = [nil] * total
list = result
end
i = 0
while i < total
group = [nil] * (size + 1)
j = size
n = i
while j > 0
j -= 1
a = arys[j]
b = a.size
group[j + 1] = a[n % b]
n /= b
end
group[0] = self[n]
list[i] = group
i += 1
end
result
end
##
# call-seq:
# ary.repeated_combination(n) { |combination| ... } -> self
# ary.repeated_combination(n) -> enumerator
#
# A +combination+ method that contains the same elements.
def repeated_combination(n, &block)
raise TypeError, "no implicit conversion into Integer" unless 0 <=> n
return to_enum(:repeated_combination, n) unless block
__repeated_combination(n, false, &block)
end
##
# call-seq:
# ary.repeated_permutation(n) { |permutation| ... } -> self
# ary.repeated_permutation(n) -> enumerator
#
# A +permutation+ method that contains the same elements.
def repeated_permutation(n, &block)
n = n.__to_int
raise TypeError, "no implicit conversion into Integer" unless 0 <=> n
return to_enum(:repeated_permutation, n) unless block
__repeated_combination(n, true, &block)
end
def __repeated_combination(n, permutation, &block)
n = n.__to_int
case n
when 0
yield []
when 1
i = 0
while i < self.size
yield [self[i]]
i += 1
end
else
if n > 0
v = [0] * n
while true
tmp = [nil] * n
i = 0
while i < n
tmp[i] = self[v[i]]
i += 1
end
yield tmp
tmp = self.size
i = n - 1
while i >= 0
v[i] += 1
break if v[i] < tmp
i -= 1
end
break unless v[0] < tmp
i = 1
while i < n
unless v[i] < tmp
if permutation
v[i] = 0
else
v[i] = v[i - 1]
end
end
i += 1
end
end
end
end
self
end
end