Ruby equivalent of Python's "dir"?
In Python we can "dir" a module, like this:
>>> import re
>>> dir(re)
And it lists all functions in the module. Is there a similar way to do this in Ruby?
As far as I know not exactly but you get somewhere with
object.methods.sort
I like to have this in my .irbrc:
class Object
def local_methods
(methods - Object.instance_methods).sort
end
end
So when I'm in irb:
>> Time.now.local_methods
=> ["+", "-", "<", "<=", "<=>", ">", ">=", "_dump", "asctime", "between?", "ctime", "day", "dst?", "getgm", "getlocal", "getutc", "gmt?", "gmt_offset", "gmtime", "gmtoff", "hour", "isdst", "localtime", "mday", "min", "mon", "month", "sec", "strftime", "succ", "to_f", "to_i", "tv_sec", "tv_usec", "usec", "utc", "utc?", "utc_offset", "wday", "yday", "year", "zone"]
Or even cuter - with grep:
>> Time.now.local_methods.grep /str/
=> ["strftime"]
Tip for "searching" for a method in irb:
"something".methods.select {|item| item =~ /query/ }
Tip for trying out methods on a value for comparison:
value = "something"
[:upcase, :downcase, :capitalize].collect {|method| [method, value.send(method)] }
Also, note that you won't get all the same information as Python's dir with object.methods. You have to use a combination of object.methods and class.constants, also class.singleton_methods to get the class methods.