Added Array#bsearch_index
MODIFY
mrbgems/mruby-array-ext/mrblib/array.rb
mrbgems/mruby-array-ext/mrblib/array.rb
@@ -595,18 +595,39 @@ class Array
def bsearch(&block)
return to_enum :bsearch unless block_given?
+ 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_given?
+
low = 0
high = size
satisfied = false
while low < high
mid = ((low+high)/2).truncate
- val = self[mid]
- res = block.call val
+ res = block.call self[mid]
case res
when 0 # find-any mode: Found!
- return val
+ return mid
when Numeric # find-any mode: Continue...
in_lower_half = res < 0
when true # find-min mode
@@ -625,7 +646,7 @@ class Array
end
end
- satisfied ? self[low] : nil
+ satisfied ? low : nil
end
##

MODIFY
mrbgems/mruby-array-ext/test/array.rb
mrbgems/mruby-array-ext/test/array.rb
@@ -267,6 +267,10 @@ assert("Array#bsearch") do
end
end
+assert("Array#bsearch_index") do
+ # tested through Array#bsearch
+end
+
assert("Array#delete_if") do
a = [1, 2, 3, 4, 5]
assert_equal [1, 2, 3, 4, 5], a.delete_if { false }

Added Array#bsearch_index