From: Ales Marecek Date: 2011-09-14T00:48:05+09:00 Subject: [ruby-core:39525] [Ruby 1.9 - Bug #4576] Range#step miss the last value, if end-exclusive and has float number Issue #4576 has been updated by Ales Marecek. Hi Kenta, thanks for the hint. The bug is about "three-dotted" range, not "double-dotted". Test with Bigdecimal works, with "quo" does NOT, with "quo" using rational lib does. $ ruby -rbigdecimal -e 'p (BigDecimal("1.0")...BigDecimal("6.4")).step(BigDecimal("1.8")).to_a' [#, #, #] $ ruby -e 'p (1...64.quo(10)).step(18.quo(10)).to_a' [1.0, 2.8, 4.6, 6.4] $ ruby -rrational -ve 'p (1...64.quo(10)).step(18.quo(10)).to_a' [1, Rational(14, 5), Rational(23, 5)] But it doesn't solve the issue we're discussing here: we have method that doesn't work in some circumstances which aren't hacks / exploits / non-standard use / on non-standard hardware... It happens on standard hardware with correct usage. ---------------------------------------- Bug #4576: Range#step miss the last value, if end-exclusive and has float number http://redmine.ruby-lang.org/issues/4576 Author: Joey Zhou Status: Closed Priority: Normal Assignee: Category: Target version: ruby -v: - =begin Hi, I find that: * if: range.exclude_end? == true * and: any one in [begin_obj, end_obj, step] is a true Float(f.to_i != f) * and: unless begin_obj + step*int == end_obj * then: the result will miss the last value. for example: p (1...6.3).step.to_a # => [1.0, 2.0, 3.0, 4.0, 5.0], no 6.0 p (1.1...6).step.to_a # => [1.1, 2.1, 3.1, 4.1], no 5.1 p (1...6).step(1.1).to_a # => [1.0, 2.1, 3.2, 4.300000000000001], no 5.4 p (1.0...6.6).step(1.9).to_a # => [1.0, 2.9], no 4.8 p (1.0...6.7).step(1.9).to_a # => [1.0, 2.9, 4.8] p (1.0...6.8).step(1.9).to_a # => [1.0, 2.9, 4.8], no 6.7 Maybe the #step is ok on integers, but there's something wrong if the range is end-exclusive and contain float numbers. =end -- http://redmine.ruby-lang.org