From: Daniel Berger <djberg96@...>
Date: 2007-05-30T11:55:17+09:00
Subject: Range#each and stringified floats - bug or feature?

Hi all,

Ruby 1.8.6
OS X 10.4.9

I searched the archives but didn't find anything definitive. Is the 
following behavior a bug or feature?

irb(main):001:0> r1 = Range.new(1.0, 3.0)
=> 1.0..3.0
irb(main):002:0> r2 = Range.new("1.0", "3.0")
=> "1.0".."3.0"
irb(main):003:0> r1.each{ |r| p r }
TypeError: can't iterate from Float
         from (irb):3:in `each'
         from (irb):3
irb(main):004:0> r2.each{ |r| p r }
"1.0"
"1.1"
"1.2"
"1.3"
"1.4"
"1.5"
"1.6"
"1.7"
"1.8"
"1.9"
"2.0"
"2.1"
"2.2"
"2.3"
"2.4"
"2.5"
"2.6"
"2.7"
"2.8"
"2.9"
"3.0"

This feels inconsistent to me, because I'm not sure what the precision 
rules are. More precise floats will give you different behavior. I 
*think* the behavior is to round to the nearest .1 of the longest 
mantissa, but that theory falls down as soon as the mantissas don't match:

irb(main):009:0> Range.new("1.0", "1.345").each{ |r| p r }
"1.0"
"1.1"
"1.2"
...
"999.9" # ???

Bug, right?

Dan