Introspection question

S

Srijayanth Sridhar

Hello,

Let us say we have a hash:

a = Hash.new

Can I do something of this sort:

class Hash
def who_am_i?
"#{self.symbol}"
end
end

Where self.symbol gives me "a"?

I basically want the variable name. I looked a bit and saw that you
could intern a symbol from a string, but is there an easy way to get
the name of a variable from within the object itself? I am writing a
to_xml method for hashes and it would be immensely helpful if I can
use the name of the variable as the root element.

Thank you,

Jayanth
 
D

David A. Black

Hi --

Hello,

Let us say we have a hash:

a = Hash.new

Can I do something of this sort:

class Hash
def who_am_i?
"#{self.symbol}"
end
end

Where self.symbol gives me "a"?

I basically want the variable name. I looked a bit and saw that you
could intern a symbol from a string, but is there an easy way to get
the name of a variable from within the object itself? I am writing a
to_xml method for hashes and it would be immensely helpful if I can
use the name of the variable as the root element.

The hash has no knowledge of how many identifiers refer to it.
Consider this:

a = Hash.new
b = a
c = b

The three identifiers are in exactly the same relation to the hash.
What is the hash supposed to think?


David
 
R

Ryan Davis

Can I do something of this sort:

class Hash
def who_am_i?
"#{self.symbol}"
end
end

Where self.symbol gives me "a"?

I totally agree with David but will take his idea a bit further:

What you're asking has what we call a "bad design smell"... I have
never seen a legitimate need for what you're asking for all the good
reasons that David mentioned. You need to look at the design of your
code and ask what you're really trying to accomplish. Something is
currently wrong with the design you're currently attempting.
 
S

Srijayanth Sridhar

Thank you both.

Jayanth

I totally agree with David but will take his idea a bit further:

What you're asking has what we call a "bad design smell"... I have never
seen a legitimate need for what you're asking for all the good reasons that
David mentioned. You need to look at the design of your code and ask what
you're really trying to accomplish. Something is currently wrong with the
design you're currently attempting.
 

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