vikrambkumar
7/13/2008 8:42:00 PM
Hi All,
I want to create a L2 cache object based on Hash.
Since it's a secondary cache, the object bound to the key may have
expired, but can be recreated.
However I want the get method itself to do get-get-set if the "value"
object has expired. Check the class definition:
#---------
class L2Cache
# use Hash for the store
def initialize
@h = Hash.new
end
# try the hash.. if not found and a block
# to recreate is provided, create the value
# and bind it again
def get(key)
value = @h[key]
if value.nil? && block_given?
puts "value is nil but recreating it using the block" if $DEBUG
value = self[key] = yield
elsif value.nil?
puts "value is nil but not recreate block found" if $DEBUG
end
value
end
# proxy to hash
def [](key)
@h[key]
end
# proxy to hash
def []=(key, value)
@h[key] = value
end
end
#---------
c = L2Cache.new
c[:k] # >> nil
c.get(:k) { "foo"} #>> foo
c[:foo] # >> foo
#----------------
However I cannot make the the default get method using [] take a block
as an argument.
If I define the method as:
#--------
def [](key)
value = @h[key]
if value.nil? && block_given?
puts "value is nil but recreating it using the block"
value = self[key] = yield
elsif value.nil?
puts "value is nil but not recreate block found"
end
value
end
#--------
I can't use c[:k] { block here }
#--------
c = L2Cache.new
c[:k] # >> nil
c.[:k] { "foo"} # >> syntax error, unexpected '{', expecting
$end
#--------
Is there a way to make methods names with special characters take
block arguments?