Reimplement String#upto

[ksss]

The documented code didn't working as expected.

"9".upto("11").to_a   #=> []
"25".upto("5").to_a   #=> ["25"]
"07".upto("11").to_a  #=> ["07", "08", "09", "10", "11"]

I've fixed like this.

"9".upto("11").to_a   #=> ["9", "10", "11"]
"25".upto("5").to_a   #=> []
"07".upto("11").to_a  #=> ["07", "08", "09", "10", "11"]

The ruby/spec for String#upto passed all without Enumerator#size (using by mruby-spec)

https://github.com/ruby/spec/blob/97fe8c7cfd7a7e4833ae2edab4df21e3ea6bc093/core/string/upto_spec.rb

before

$ make TESTS=spec/core/string/upto
...
mruby 1.2.0 (2015-11-17)

1)
String#upto doesn't call block with self even if self is less than stop but stop length is less than self length FAILED
Expected ["25"] to equal []
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:20:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each

2)
String#upto tries to convert other to string using to_str ERROR
TypeError: non float value
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrbgems/mruby-string-ext/mrblib/string.rb:341:in upto
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:51:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each

3)
String#upto returns non-alphabetic characters in the ASCII range for single letters FAILED
Expected ["9"] to equal ["9", ":", ";", "<", "=", ">", "?", "@", "A"]
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:66:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each

4)
String#upto on sequence of numbers calls the block as Integer#upto FAILED
Expected [] to equal ["8", "9", "10", "11"]
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:79:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each

5)
String#upto when no block is given returned Enumerator size should return nil ERROR
NoMethodError: undefined method 'size' for #<Enumerator:0x7fa215023510>
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:93:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
[- | ==================100%================== | 00:00:00]      3     F      2     E

Finished in 0.012235 seconds

1 file, 15 examples, 16 expectations, 3 failures, 2 errors, 0 tagged
make: *** [run] Error 1

after

$ make TESTS=spec/core/string/upto
...
mruby 1.2.0 (2015-11-17)

1)
String#upto when no block is given returned Enumerator size should return nil ERROR
NoMethodError: undefined method 'size' for #<Enumerator:0x7ff048057300>
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:93:in protect
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/enum.rb:26:in all?
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/numeric.rb:77:in times
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
/Users/ksss/src/github.com/ksss/mruby-spec/spec/core/string/upto_spec.rb:98
/Users/ksss/src/github.com/ksss/mruby-spec/mruby/mrblib/array.rb:17:in each
[- | ==================100%================== | 00:00:00]      0     F      1     E

Finished in 0.007707 seconds

1 file, 15 examples, 19 expectations, 0 failures, 1 error, 0 tagged
make: *** [run] Error 1

[matz]

Thank you. But under the current implementation, we want to avoid using mrb_yield from C code. Using break within a block may cause unexpected result.

[ksss]

@matz Should I write in Ruby?
It's somewhat inefficient.

class String
  def upto(other_str, excl=false, &block)
    return to_enum :upto, other_str, excl unless block
    unless other_str = String.try_convert(other_str)
      raise TypeError, "no implicit conversion of #{other_str.class} into String"
    end

    # single character
    if bytesize == 1 && other_str.bytesize == 1
      c = bytes[0]
      e = other_str.bytes[0]
      return self if c > e || excl && c == e
      while 1
        block.call(c.chr)
        break if !excl && c == e
        c += 1
        break if excl && c == e
      end

      return self
    end

    # both edges are all digits
    if self != "0" && other_str != "0" && (b = self.to_i) > 0 && (e = other_str.to_i) > 0
      min_width = length
      max_width = other_str.length
      while b <= e
        break if excl && b == e
        bs = b.to_s
        bs = "#{"0" * (min_width - bs.length)}#{bs}" if min_width > bs.length
        block.call(bs)
        b += 1
      end

      return self
    end

    # normal case
    n = self <=> other_str
    return self if n > 0 || (excl && n == 0)
    after_end = other_str.succ
    current = dup
    while current != after_end
      nxt = nil
      nxt = current.succ if excl || current != other_str
      block.call(current)
      break if nxt.nil?
      current = nxt
      break if excl && current == other_str
      break if current.length > other_str.length || current.empty?
    end

    self
  end
end

t.rb

t = Time.now
"000001".upto("100000").each {}
p Time.now - t

t = Time.now
"aaa".upto("zzz").each {}
p Time.now - t

C implementation

$ mruby t.rb
0.112704
0.056333

Ruby implementation

$ mruby t.rb
0.416623
0.121773

[matz]

I am trying to solve the issue, but at the moment, I don't recommend to use mrb_yield in your C code.

[matz]

I am talking about #3359

[ksss]

Thank you so much!