rb_require() for strings

[Guilherme T.]

I'd like to use rb_require(), but instead of a filename give it a
string with the contents to be required. How would I go about doing
this?

Thanks in advance

 

[Robert Klemme]

I'd like to use rb_require(), but instead of a filename give it a
string with the contents to be required. How would I go about doing
this?

What you want to do is basically execute a piece of code once, right? In
that case you could do something like this:

Cheap solution:

$code_snippets ||= Hash.new {|h,code| h

 = eval( code ) }


# will print "buh!" only once
$code_snippets[ 'puts "buh"' ]
# ...
$code_snippets[ 'puts "buh"' ]


A bit nicer

module Code
def self.snippets
@code_snippets ||= Hash.new {|h,code| h[code] = eval( code ) }
end

def self.require( code )
snippets[ code ]
end
end

# will print "bah!" only once
Code.require 'puts "bah!"'
Code.require 'puts "bah!"'
Code.require 'puts "bah!"'
Code.require 'puts "bah!"'

Regards

robert

 

[Charles Mills]

I'd like to use rb_require(), but instead of a filename give it a
string with the contents to be required. How would I go about doing
this?

Thanks in advance

I think you want rb_eval_string() from ruby.h
Basically the string you pass is evaluated by the parser. For example:
rb_eval_string("puts 'hey'");
would return Qnil and print "hey\n" to standard out.

Others you may want to consider:
$ grep rb_eval *.h
intern.h:VALUE rb_eval_cmd _((VALUE, VALUE, int));
ruby.h:VALUE rb_eval_string _((const char*));
ruby.h:VALUE rb_eval_string_protect _((const char*, int*));
ruby.h:VALUE rb_eval_string_wrap _((const char*, int*));

-Charlie