converting strings to booleans, symbols, etc

[an an]

Hi,

I am parsing an xml document, and I wanted to know if there is a quick
built in way to convert a string to a symbol or a boolean. an example
xml doc would be:

<test id="first" search="false">data</test>

Now I know I can do some string compares, and set the variable
accordingly, but I was wondering if there are shortcuts, much like the
to_i method.

thanks!

 

[Day]

I am parsing an xml document, and I wanted to know if there is a quick
built in way to convert a string to a symbol or a boolean.

The symbol is easy, anyway:
http://www.ruby-doc.org/core/classes/String.html#M000825

Once you're there, making a compare for true/false isn't so much code.
But maybe someone else has a cleaner solution to that.


Ben

 

[an an]

The symbol is easy, anyway:
http://www.ruby-doc.org/core/classes/String.html#M000825

Once you're there, making a compare for true/false isn't so much code.
But maybe someone else has a cleaner solution to that.


Ben

thanks...thats the type of stuff i was looking for...im used to java,
and I am actively tried to avoid coding Java style in ruby, but
sometimes its hard to figure out the shortcuts that ruby provides

 

[Tim Pease]

Hi,

I am parsing an xml document, and I wanted to know if there is a quick
built in way to convert a string to a symbol or a boolean. an example
xml doc would be:

<test id="first" search="false">data</test>

Now I know I can do some string compares, and set the variable
accordingly, but I was wondering if there are shortcuts, much like the
to_i method.

Here some sample code to get your brain churning ...

class String
# The inverse of 'to_s'
def s_ot
begin
return Integer(self)
rescue ArgumentError
(return Float(self)) rescue nil
end

case self
when %r/^true|yes$/i; true
when %r/^false|no$/i; false
when %r/^nil|none$/i; nil
when %r/^:\w+$/; self.tr(':','').to_sym
else self end
end
end

"1.0".s_ot #=> 1.0 (as a Float)
"2".s_ot #=> 2 (as a Fixnum)
"no".s_ot #=> false
"none".s_ot #=> nil
":string".s_ot #=> :string (as a Symbol)


Happy Friday everyone!

Blessings,
TwP

 

[Robert Klemme]

Hi,

I am parsing an xml document, and I wanted to know if there is a quick
built in way to convert a string to a symbol or a boolean. an example
xml doc would be:

<test id="first" search="false">data</test>

Now I know I can do some string compares, and set the variable
accordingly, but I was wondering if there are shortcuts, much like the
to_i method.

You can create yourself some. One example:

CONV = {
"false" => false,
"true" => true,
"0" => 0,
"1" => 1,
# more common / important values
}

def convert(s)
x = CONV

if x.nil?
x = case x
when /\A[+-]?\d+\z/
s.to_i
when /\A[+-]?\d+(?:\.\d+)?\z/
s.to_f
# more
else
x
end
end

x
end

Kind regards

robert