Possible ScriptEngine and parsing bug when converting block to a parameter

I was getting an error trying to use ScriptEngine to require
‘win32ole’ (Actually, I need this from C#, below example given because
its easier to show in IronRuby):

IronRuby.create_engine.execute_file(‘Libs\win32ole.rb’)
:0: `&’ interpreted as argument prefix
(Microsoft::Scripting::SyntaxErrorException)

Looks like it fails on this line(63):

result = strongly_typed_enumerable.each &b
#result = strongly_typed_enumerable.each(&b) #Works just fine if we
add parens around &b

However, ir.exe reads the file with NO error if we just do a normal
“require”.
This is where I’m not sure if this is a bug.
Do ScriptEngine and IR.exe (run interactively ONLY) have stricter
parsing requirements?
I investigated a bit further to get a simpler repro and found some
interesting results.

Fine processing the code directly:

ruby -e"b = lambda { |x| p x };result = [1,2].each &b"
1
2

rbx -e"b = lambda { |x| p x };result = [1,2].each &b"
1
2

Argument error comes ONLY when running interactively (or through the
ScriptEngine as shown above):

irb
irb(main):001:0> b = lambda { |x| p x };result = [1,2].each &b
1
2
=> [1, 2]

rbx
IronRuby 0.9.1.0 on .NET 2.0.50727.3082
Copyright © Microsoft Corporation. All rights reserved.

b = lambda { |x| p x };result = [1,2].each &b
unknown: `&’ interpreted as argument prefix
(Microsoft::Scripting::SyntaxErrorException)

Again, fine through ir.exe interactive if I parameterize the block:
b = lambda { |x| p x };result = [1,2].each(&b)

Thanks
Best Regards,
Kevin

Looks like a bug in win32ole.rb:

D:\M5\Merlin\Main\Languages\Ruby>ruby -w libs\win32ole.rb
libs/win32ole.rb:63: warning: `&’ interpreted as argument prefix

The default warning levels seem to be different when hosted. It would
probably be better to set the default warning level on the same level as
ir.exe/ruby does.

Will fix both.

Tomas

Great! Tomas, thanks also for the speedy follow-up email.
Best Regards,
Kevin

On Fri, Oct 2, 2009 at 12:41 PM, Tomas M.