Hi!
Is there a way that methods defined with define_method can take a block?
Here’s my fighting module:
module Taikwando
def self.add_warrior(n)
define_method(n) do
puts “#{n} fights!”
yield
end
end
def fight(*names)
names.each do |n|
Taikwando.add_warrior(n)
end
end
end
include Taikwando
…when I require it, I can do this:
fight “morpheus”, “neo”
=> [“morpheus”, “neo”]
neo do
?> puts “karate chop!”
end
neo fights!
LocalJumpError: no block given
from ./kungfu.rb:102:in `neo’
from (irb):5
- the yield does not work. Any ideas?
Les
2008/6/27 Leslie V. [email protected]:
from (irb):5
- the yield does not work. Any ideas?
AFAIK there is no way (yet) to define a method that needs a block via
define_method. I believe you can try to work around this by doing
self.class.class_eval “def #{m}; puts ‘#{m} fights’; yield; end”
Kind regards
robert
On 6/27/08, Robert K. [email protected] wrote:
yield
include Taikwando
neo fights!
self.class.class_eval “def #{m}; puts ‘#{m} fights’; yield; end”
Kind regards
robert
I can explicitly pass a block to my fight method too, but it’s so ugly:
neo(lambda do
puts “flying kick”
end
)
I’ve re-arranged a bit your code… maybe this way can be more
nice-looking:
module Taikwando
def self.add_warrior(n)
define_method(n) do |blk|
puts “#{n} fights!”
blk.call
end
end
def fight(*names)
names.each do |n|
Taikwando.add_warrior(n)
end
end
def moves (fighter,&block)
self.send(fighter,block)
end
end
include Taikwando
fight “morpheus”, “neo”
moves(“neo”) do
puts “karate chop!”
end
On Fri, Jun 27, 2008 at 11:48 AM, Leslie V.
[email protected]
2008/6/27 Robert D. [email protected]:
On Fri, Jun 27, 2008 at 1:21 PM, Leslie V. [email protected] wrote:
Hi!
Is there a way that methods defined with define_method can take a block?
Short answers
1.8 : No
1.9 : Yes
1.9 is still a bit inconsistent here IMHO:
irb(main):001:0> RUBY_VERSION
=> “1.9.0”
irb(main):002:0> class Foo
irb(main):003:1> define_method(:bar) do
irb(main):004:2* yield 123
irb(main):005:2> end
irb(main):006:1> end
=> #<Proc:0x7feeea10@(irb):4 (lambda)>
irb(main):007:0> Foo.new.bar {|x| p x}
LocalJumpError: no block given (yield)
from (irb):4:in block (1 levels) in <class:Foo>' from (irb):7 from /opt/lib/ruby/1.9.0/irb.rb:149:in block (2 levels) in
eval_input’
from /opt/lib/ruby/1.9.0/irb.rb:262:in signal_status' from /opt/lib/ruby/1.9.0/irb.rb:146:in block in eval_input’
from /opt/lib/ruby/1.9.0/irb.rb:145:in eval_input' from /opt/lib/ruby/1.9.0/irb.rb:69:in block in start’
from /opt/lib/ruby/1.9.0/irb.rb:68:in catch' from /opt/lib/ruby/1.9.0/irb.rb:68:in start’
from /opt/bin/irb19:12:in `’
irb(main):008:0> class Foo
irb(main):009:1> define_method(:bar) do |&b|
irb(main):010:2* b[123]
irb(main):011:2> end
irb(main):012:1> end
=> #<Proc:0x7fee49c0@(irb):10 (lambda)>
irb(main):013:0> Foo.new.bar {|x| p x}
123
=> 123
irb(main):014:0>
Kind regards
robert
On Fri, Jun 27, 2008 at 1:21 PM, Leslie V.
[email protected] wrote:
Hi!
Is there a way that methods defined with define_method can take a block?
Short answers
1.8 : No
1.9 : Yes
HTH
Robert
–
http://ruby-smalltalk.blogspot.com/
AALST (n.) One who changes his name to be further to the front
D.Adams; The Meaning of LIFF
On Fri, Jun 27, 2008 at 4:45 PM, Robert K.
[email protected] wrote:
2008/6/27 Robert D. [email protected]:
On Fri, Jun 27, 2008 at 1:21 PM, Leslie V. [email protected] wrote:
Hi!
Is there a way that methods defined with define_method can take a block?
Short answers
1.8 : No
1.9 : Yes
Good of Robert to point out that 1.9 is not yet stable of course, but
this is a feature that will work :).
Cheers
Robert
–
http://ruby-smalltalk.blogspot.com/
AALST (n.) One who changes his name to be further to the front
D.Adams; The Meaning of LIFF
On 6/27/08, Sandro P. [email protected] wrote:
end
end
end
include Taikwando
fight “morpheus”, “neo”
moves(“neo”) do
puts “karate chop!”
end
Ok, that’s a bit better, thanks!
Les