Ruby - Question about Inheritance

Author

Question about Inheritance

Michael Jessop

2005-08-30, 7:02 pm

I have two simple classes. One inherits from the other and calls
"super()" in its initialize method. But the super does not seem to do
what I expect it to do. I expect the super() to initialize two
variables, but when I call the method to display the initialized
errors, I do not get the value (it things @errmsg is nil). Here they
are:

class DBBase
def initalize
@failed = false
@errmsg = 'n/a'
end

def clear
@failed = false
@errmsg = 'n/a'
end

def failure
@failed
end

def success
@failed != true
end

def error
"Error: #{@errmsg}"
end

def connect
SQLite::Database.new(DBNAME)
end

attr_accessor :failed, :errmsg
end

(and here is the shortened version of the inheriting class)...

## This class models the People table. It allows the creation,
## loading, modification and saving of a single person.

class Person < DBBase
def initialize(id=nil, lname=nil, fname=nil, mname=nil, nname=nil,
sex=nil, dob=nil)
super()
@id = id
@lname = lname
@fname = fname
@mname = mname
@nname = nname
@sex = sex
@dob = dob

if @id != nil
@added = false
else
@added = true
end

@modified = false
@loaded = false
end

--------------------------

Jamey Cribbs

2005-08-30, 7:02 pm

Michael Jessop wrote:

> I have two simple classes. One inherits from the other and calls
> "super()" in its initialize method. But the super does not seem to do
> what I expect it to do. I expect the super() to initialize two
> variables, but when I call the method to display the initialized
> errors, I do not get the value (it things @errmsg is nil). Here they
> are:
>
> class DBBase
> def initalize
> @failed = false
> @errmsg = 'n/a'
> end

The initialize method in class DBBase is spelled incorrectly.

Jamey

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Michael Jessop

2005-08-30, 7:02 pm

Oh for the love of friggin' PETE! I spent an hour on this!!!!!!!!!!

I wish you were here so you could smack me with bat.

Thanks!

Mike

On 2005-08-30 13:28:46 -0700, Jamey Cribbs <cribbsj@oakwood.org> said:

> Michael Jessop wrote:
>
>
> The initialize method in class DBBase is spelled incorrectly.
>
> Jamey
>
> Confidentiality Notice: This email message, including any attachments,
> is for the sole use of the intended recipient(s) and may contain
> confidential and/or privileged information. If you are not the intended
> recipient(s), you are hereby notified that any dissemination,
> unauthorized review, use, disclosure or distribution of this email and
> any materials contained in any attachments is prohibited. If you
> receive this message in error, or are not the intended recipient(s),
> please immediately notify the sender by email and destroy all copies of
> the original message, including attachments.

Joel VanderWerf

2005-08-30, 7:02 pm

Just for fun...

$ ruby code-nanny.rb
Did you type too fast again? 'initalize' != 'initialize'
Did you type too fast again? 'intialize' != 'initialize'
Did you type too fast again? 'inaltiaez' != 'initialize'
Did you type too fast again? 'initiliaze' != 'initialize'
$ cat code-nanny.rb
module CodeNanny
def method_added(m)
if /^in[ital]{2,6}[alize]{2,6}\b/ =~ m.to_s
if m != :initialize
warn "Did you type too fast again? '#{m}' != 'initialize'"
end
end
end
end

class Foo
extend CodeNanny
def initialize
end

def initalize
end

def intialize
end

def inaltiaez
end

def initiliaze
end
end

Foo.new

Michael Jessop wrote:
> Oh for the love of friggin' PETE! I spent an hour on this!!!!!!!!!!
>
> I wish you were here so you could smack me with bat.
>
> Thanks!
>
> Mike
>
> On 2005-08-30 13:28:46 -0700, Jamey Cribbs <cribbsj@oakwood.org> said:
>
>
>
>

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

Martin DeMello

2005-08-31, 7:57 am

Joel VanderWerf <vjoel@path.berkeley.edu> wrote:
>
> Just for fun...
>
> $ ruby code-nanny.rb
> Did you type too fast again? 'initalize' != 'initialize'
> Did you type too fast again? 'intialize' != 'initialize'
> Did you type too fast again? 'inaltiaez' != 'initialize'
> Did you type too fast again? 'initiliaze' != 'initialize'
> $ cat code-nanny.rb
> module CodeNanny
> def method_added(m)
> if /^in[ital]{2,6}[alize]{2,6}\b/ =~ m.to_s
> if m != :initialize
> warn "Did you type too fast again? '#{m}' != 'initialize'"
> end
> end
> end
> end

You missed 'initialise'! (I remember various ruby-lint projects being
mentioned in the past - anyone know what happened to them?)

martin

Joel VanderWerf

2005-08-31, 7:00 pm

Martin DeMello wrote:
> Joel VanderWerf <vjoel@path.berkeley.edu> wrote:
>
>
>
> You missed 'initialise'! (I remember various ruby-lint projects being
> mentioned in the past - anyone know what happened to them?)
>
> martin

:) I almost added that, but I coudn't think of a humorous way to accuse
the programmer of being a Queen's English speaker (maybe that's humorous
enough as it is).

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

Joel VanderWerf

2005-08-31, 7:00 pm

If any one really wants to use this, then to make sure there are no
false positives, we should permit #initial. According to one local
dictionary on my system, initial and initialize are the only matches for
the regex.

module CodeNanny
def method_added(m)
if /^in[ital]{2,6}[alize]{2,6}\b/ =~ m.to_s
if m != :initialize and m != :initial
warn "Did you type too fast again? '#{m}' != 'initialize'"
end
end
end
end

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

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