method

class_eval

v1_8_7_330 - Show latest stable - 0 notes - Class: Module

class_eval(...) public

Evaluates the string or block in the context of mod. This can be used to add methods to a class. module_eval returns the result of evaluating its argument. The optional filename and lineno parameters set the text for error messages.

class Thing
end
a = %q{def hello() "Hello there!" end}
Thing.module_eval(a)
puts Thing.new.hello()
Thing.module_eval("invalid code", "dummy", 123)

produces:

Hello there!
dummy:123:in `module_eval': undefined local variable
    or method `code' for Thing:Class

Show source

/*
 *  call-seq:
 *     mod.class_eval(string [, filename [, lineno]])  => obj
 *     mod.module_eval {|| block }                     => obj
 *  
 *  Evaluates the string or block in the context of _mod_. This can
 *  be used to add methods to a class. <code>module_eval</code> returns
 *  the result of evaluating its argument. The optional _filename_
 *  and _lineno_ parameters set the text for error messages.
 *     
 *     class Thing
 *     end
 *     a = %q{def hello() "Hello there!" end}
 *     Thing.module_eval(a)
 *     puts Thing.new.hello()
 *     Thing.module_eval("invalid code", "dummy", 123)
 *     
 *  <em>produces:</em>
 *     
 *     Hello there!
 *     dummy:123:in `module_eval': undefined local variable
 *         or method `code' for Thing:Class
 */

VALUE
rb_mod_module_eval(argc, argv, mod)
    int argc;
    VALUE *argv;
    VALUE mod;
{
    return specific_eval(argc, argv, mod, mod);
}

class_eval

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