Hello,
I have the following:
class DSL
def DSL.load filename
dsl = new
dsl.instance_eval(File.read(filename))
dsl
end
def to sym,*args,&block
if block_given?
b=class << self;self;end
b.instance_eval {
define_method(sym,*args,&block)
}
end
end
def method_missing sym,*args
"#{sym}"
end
alias :say puts
end
foo=DSL.load("sample.dsl")
sample.dsl:
to smile do
say ":)"
end
to be_polite {
say "thank you"
}
smile
be_polite
The resulting output is:
moonwolf@trantor:~/ruby/dsl/todo$ ./dsl.rb
moonwolf@trantor:~/ruby/dsl/todo$
be_polite and indeed, anything enclosded in {} doesn't seem to be eval-ed as
blocks. Why is this?
Jayanth
This is definitely not a block_given thing.
block is coming through as a NilClass it seems.
puts block.class yields NilClass. The strange bit is that when I do it
outside of instance_eval with just a define_method under irb, it works as
expected. I am lost.
Anyone?
Jayanth
···
On Fri, May 8, 2009 at 11:19 AM, Srijayanth Sridhar <srijayanth@gmail.com>wrote:
Hello,
I have the following:
class DSL
def DSL.load filename
dsl = new
dsl.instance_eval(File.read(filename))
dsl
end
def to sym,*args,&block
if block_given?
b=class << self;self;end
b.instance_eval {
define_method(sym,*args,&block)
}
end
end
def method_missing sym,*args
"#{sym}"
end
alias :say puts
end
foo=DSL.load("sample.dsl")
sample.dsl:
to smile do
say ":)"
end
to be_polite {
say "thank you"
}
smile
be_polite
The resulting output is:
moonwolf@trantor:~/ruby/dsl/todo$ ./dsl.rb
moonwolf@trantor:~/ruby/dsl/todo$
be_polite and indeed, anything enclosded in {} doesn't seem to be eval-ed
as
blocks. Why is this?
Jayanth
[Note: parts of this message were removed to make it a legal post.]
This is definitely not a block_given thing.
It's an operator precedence thing. {} binds at a higher precedence than
do/end, meaning that, in the absence of parentheses, in one case, it's
the first function that takes the block and in the other, it's the
second one.
For instance :
def test ; (block_given? ? 'block' : 'no block') ; end
=> nil
puts test do end
no block
=> nil
puts test { }
block
In the first case, it's puts who gets the block (and discards it). In
the second case, it's my function. Compare to :
puts(test) do end
no block
=> nil
puts(test) {}
no block
=> nil
puts(test do end)
block
=> nil
puts(test {})
block
Fred
···
Le 08 mai à 11:42, Srijayanth Sridhar a écrit :
--
Just a reflection Just a glimpse Just a little reminder Of all the
what abouts And all the might have Could have beens Another day Some
other way But not another reason to continue And now you're one of us
The wretched (Nine Inch Nails, The Wretched)