object.c

00001 #include "mruby.h"
00002 #include "mruby/array.h"
00003 #include "mruby/class.h"
00004 
00005 /*
00006  *  call-seq:
00007  *     nil.to_a    -> []
00008  *
00009  *  Always returns an empty array.
00010  */
00011 
00012 static mrb_value
00013 nil_to_a(mrb_state *mrb, mrb_value obj)
00014 {
00015   return mrb_ary_new(mrb);
00016 }
00017 
00018 /*
00019  *  call-seq:
00020  *     nil.to_f    -> 0.0
00021  *
00022  *  Always returns zero.
00023  */
00024 
00025 static mrb_value
00026 nil_to_f(mrb_state *mrb, mrb_value obj)
00027 {
00028   return mrb_float_value(mrb, 0.0);
00029 }
00030 
00031 /*
00032  *  call-seq:
00033  *     nil.to_i    -> 0
00034  *
00035  *  Always returns zero.
00036  */
00037 
00038 static mrb_value
00039 nil_to_i(mrb_state *mrb, mrb_value obj)
00040 {
00041   return mrb_fixnum_value(0);
00042 }
00043 
00044 /*
00045  *  call-seq:
00046  *     obj.instance_exec(arg...) {|var...| block }                       -> obj
00047  *
00048  *  Executes the given block within the context of the receiver
00049  *  (_obj_). In order to set the context, the variable +self+ is set
00050  *  to _obj_ while the code is executing, giving the code access to
00051  *  _obj_'s instance variables.  Arguments are passed as block parameters.
00052  *
00053  *     class KlassWithSecret
00054  *       def initialize
00055  *         @secret = 99
00056  *       end
00057  *     end
00058  *     k = KlassWithSecret.new
00059  *     k.instance_exec(5) {|x| @secret+x }   #=> 104
00060  */
00061 
00062 static mrb_value
00063 mrb_obj_instance_exec(mrb_state *mrb, mrb_value self)
00064 {
00065   mrb_value *argv;
00066   mrb_int argc;
00067   mrb_value blk;
00068   struct RClass *c;
00069 
00070   mrb_get_args(mrb, "*&", &argv, &argc, &blk);
00071 
00072   if (mrb_nil_p(blk)) {
00073     mrb_raise(mrb, E_ARGUMENT_ERROR, "no block given");
00074   }
00075 
00076   switch (mrb_type(self)) {
00077   case MRB_TT_SYMBOL:
00078   case MRB_TT_FIXNUM:
00079   case MRB_TT_FLOAT:
00080     c = NULL;
00081     break;
00082   default:
00083     c = mrb_class_ptr(mrb_singleton_class(mrb, self));
00084     break;
00085   }
00086 
00087   return mrb_yield_with_class(mrb, blk, argc, argv, self, c);
00088 }
00089 
00090 void
00091 mrb_mruby_object_ext_gem_init(mrb_state* mrb)
00092 {
00093   struct RClass * n = mrb->nil_class;
00094 
00095   mrb_define_method(mrb, n, "to_a", nil_to_a,       MRB_ARGS_NONE());
00096   mrb_define_method(mrb, n, "to_f", nil_to_f,       MRB_ARGS_NONE());
00097   mrb_define_method(mrb, n, "to_i", nil_to_i,       MRB_ARGS_NONE());
00098 
00099   mrb_define_method(mrb, mrb->object_class, "instance_exec", mrb_obj_instance_exec, MRB_ARGS_ANY() | MRB_ARGS_BLOCK());
00100 }
00101 
00102 void
00103 mrb_mruby_object_ext_gem_final(mrb_state* mrb)
00104 {
00105 }
00106