[BUG] Unexpected syntax error

ruby-talk
1

$ ruby -v
ruby 1.8.4 (2005-12-24) [powerpc-darwin8.3.0]

# Example to illustrate the problem
def foo1
   p (1..10).method(:each)
end

def foo2()
   p((1..10).method(:each))
end

def foo3()
   p (1..10).method(:each)
end

foo1 # -> No error
foo2 # -> No error
foo3 # -> Error

__END__

-- Daniel

2

Daniel Harple wrote:

$ ruby -v
ruby 1.8.4 (2005-12-24) [powerpc-darwin8.3.0]

# Example to illustrate the problem
def foo1
   p (1..10).method(:each)
end

def foo2()
   p((1..10).method(:each))
end

def foo3()
   p (1..10).method(:each)
end

foo1 # -> No error
foo2 # -> No error
foo3 # -> Error

__END__

This is quite bizarre. The parentheses on foo3 cause
the problem; leaving them out, adding a semicolon after
them or creating a temporary variable instead of the
direct p will all solve the error.

I would, though, venture that this should not be an
error :slight_smile:

-- Daniel

E

···

--
Posted via http://www.ruby-forum.com/\.

3

Hi,

From: Daniel Harple <dharple@generalconsumption.org>
Reply-To: ruby-talk@ruby-lang.org
To: ruby-talk@ruby-lang.org (ruby-talk ML)
Subject: [BUG] Unexpected syntax error
Date: Mon, 20 Feb 2006 09:10:54 +0900

$ ruby -v
ruby 1.8.4 (2005-12-24) [powerpc-darwin8.3.0]

# Example to illustrate the problem
def foo1
  p (1..10).method(:each)
end

def foo2()
  p((1..10).method(:each))
end

def foo3()
  p (1..10).method(:each)
end

foo1 # -> No error
foo2 # -> No error
foo3 # -> Error

__END__

-- Daniel

It reminds me an old thread
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/12896

def foo1
  p (2.4/0.2).to_i
end
def foo2()
  p ((2.4/0.2).to_i)
end
def foo3()
  p (2.4/0.2).to_i
end

foo1 # -> 11
foo2 # -> 11
foo3 # -> 12.0

__END__

Regards,

Park Heesob

4

Ruby thinks those are argument parentheses. This may not be a bug.

-:11: warning: don't put space before argument parentheses
#<Method: Range#each>
1..10
-:11:in `method': undefined method `each' for class `NilClass' (NameError)
         from -:11:in `foo3'
         from -:16
$ parse_tree_show -f
p (1..10).method(:each)
(eval):1: warning: (...) interpreted as grouped expression
[[:class,
   :Example,
   :Object,
   [:defn,
    :example,
    [:scope,
     [:block,
      [:args],
      [:fcall,
       :p,
       [:array, [:call, [:lit, 1..10], :method, [:array, [:lit, :each]]]]]]]]]]

···

On Feb 19, 2006, at 4:10 PM, Daniel Harple wrote:

$ ruby -v
ruby 1.8.4 (2005-12-24) [powerpc-darwin8.3.0]

# Example to illustrate the problem
def foo1
  p (1..10).method(:each)
end

def foo2()
  p((1..10).method(:each))
end

def foo3()
  p (1..10).method(:each)
end

foo1 # -> No error
foo2 # -> No error
foo3 # -> Error

--
Eric Hodel - drbrain@segment7.net - http://segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com

5

Hi,

···

In message "Re: Unexpected syntax error" on Tue, 21 Feb 2006 04:07:51 +0900, Eric Hodel <drbrain@segment7.net> writes:

Ruby thinks those are argument parentheses. This may not be a bug.

This is a bug, and I fixed it last night(JST).

              matz.