From 33379025f80282e59b4f4aff60190f2951a768db Mon Sep 17 00:00:00 2001 From: yugui Date: Wed, 28 Jan 2009 11:09:51 +0000 Subject: merges r21660 from trunk into ruby_1_9_1. * vm_eval.c, eval.c (rb_f_block_given_p): move definition of "iterator?" and "block_given?" to make static. * vm.c (vm_get_ruby_level_caller_cfp): make it static. * eval_intern.h, vm_insnhelper.c: move decl. of vm_get_ruby_level_caller_cfp() from eval_intern.h to vm_insnhelper.c. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@21850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- vm_eval.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'vm_eval.c') diff --git a/vm_eval.c b/vm_eval.c index 74d70d33d7..2c98758dbe 100644 --- a/vm_eval.c +++ b/vm_eval.c @@ -1376,11 +1376,52 @@ rb_f_local_variables(void) return ary; } +/* + * call-seq: + * block_given? => true or false + * iterator? => true or false + * + * Returns true if yield would execute a + * block in the current context. The iterator? form + * is mildly deprecated. + * + * def try + * if block_given? + * yield + * else + * "no block" + * end + * end + * try #=> "no block" + * try { "hello" } #=> "hello" + * try do "hello" end #=> "hello" + */ + + +VALUE +rb_f_block_given_p(void) +{ + rb_thread_t *th = GET_THREAD(); + rb_control_frame_t *cfp = th->cfp; + cfp = vm_get_ruby_level_caller_cfp(th, RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp)); + + if (cfp != 0 && + (cfp->lfp[0] & 0x02) == 0 && + GC_GUARDED_PTR_REF(cfp->lfp[0])) { + return Qtrue; + } + else { + return Qfalse; + } +} + void Init_vm_eval(void) { rb_define_global_function("eval", rb_f_eval, -1); rb_define_global_function("local_variables", rb_f_local_variables, 0); + rb_define_global_function("iterator?", rb_f_block_given_p, 0); + rb_define_global_function("block_given?", rb_f_block_given_p, 0); rb_define_global_function("catch", rb_f_catch, -1); rb_define_global_function("throw", rb_f_throw, -1); -- cgit v1.2.3