symbols_and_ranges/binary_search_parens.rb

tests/_examples/symbols_and_ranges/binary_search_parens.rb in the metorex repository.

# `bsearch` halves a numeric range: a block answering true or false finds the
# smallest element it says yes to, and one answering a number finds the
# element it answers zero for.
p((0..10).bsearch { |number| number >= 4 })
p((0...4).bsearch { |number| number >= 4 })
p((0..10).bsearch { |number| number < 3 ? 1 : number > 3 ? -1 : 0 })
p((0..10).bsearch { nil })
p((1.0..3.0).bsearch { |number| number >= 3.0 })
p((0..).bsearch { |number| number >= 7 })
p((..10).bsearch { |number| number >= 2 })
p((0..1).bsearch.class)

begin
  ("a".."e").bsearch { true }
rescue TypeError => problem
  puts(problem.message)
end

begin
  (0..1).bsearch { Object.new }
rescue TypeError => problem
  puts(problem.message)
end

Output:

4
nil
3
nil
3.0
7
2
Enumerator
can't do binary search for String
wrong argument type Object (must be numeric, true, false or nil)