Increasing docs coverage

.yardopts

 --plugin mruby
 --plugin coderay
 --output-dir doc/api
+
+src/**/*.c
+mrblib/**/*.rb
+include/**/*.h
+
+mrbgems/*/src/**/*.c
+mrbgems/*/mrblib/**/*.rb
+mrbgems/*/include/**/*.h
 -
 AUTHORS
 MITL

include/mruby.h

@@ -887,9 +887,26 @@ MRB_API mrb_value mrb_attr_get(mrb_state *mrb, mrb_value obj, mrb_sym id);
 MRB_API mrb_bool mrb_respond_to(mrb_state *mrb, mrb_value obj, mrb_sym mid);
 MRB_API mrb_bool mrb_obj_is_instance_of(mrb_state *mrb, mrb_value obj, struct RClass* c);
 
-/* fiber functions (you need to link mruby-fiber mrbgem to use) */
+
+/*
+ * Resume a Fiber
+ *
+ * @mrbgem mruby-fiber
+ */
 MRB_API mrb_value mrb_fiber_resume(mrb_state *mrb, mrb_value fib, mrb_int argc, const mrb_value *argv);
+
+/*
+ * Yield a Fiber
+ *
+ * @mrbgem mruby-fiber
+ */
 MRB_API mrb_value mrb_fiber_yield(mrb_state *mrb, mrb_int argc, const mrb_value *argv);
+
+/*
+ * FiberError reference
+ *
+ * @mrbgem mruby-fiber
+ */
 #define E_FIBER_ERROR (mrb_class_get(mrb, "FiberError"))
 
 /* memory pool implementation */

src/array.c

@@ -1068,7 +1068,7 @@ mrb_init_array(mrb_state *mrb)
 {
   struct RClass *a;
 
-  a = mrb->array_class = mrb_define_class(mrb, "Array", mrb->object_class);            /* 15.2.12 */
+  mrb->array_class = a = mrb_define_class(mrb, "Array", mrb->object_class);            /* 15.2.12 */
   MRB_SET_INSTANCE_TT(a, MRB_TT_ARRAY);
 
   mrb_define_class_method(mrb, a, "[]",        mrb_ary_s_create,     MRB_ARGS_ANY());  /* 15.2.12.4.1 */

src/hash.c

@@ -827,7 +827,7 @@ mrb_init_hash(mrb_state *mrb)
 {
   struct RClass *h;
 
-  h = mrb->hash_class = mrb_define_class(mrb, "Hash", mrb->object_class);              /* 15.2.13 */
+  mrb->hash_class = h = mrb_define_class(mrb, "Hash", mrb->object_class);              /* 15.2.13 */
   MRB_SET_INSTANCE_TT(h, MRB_TT_HASH);
 
   mrb_define_method(mrb, h, "[]",              mrb_hash_aget,        MRB_ARGS_REQ(1)); /* 15.2.13.4.2  */

src/kernel.c

@@ -1097,7 +1097,7 @@ mrb_init_kernel(mrb_state *mrb)
 {
   struct RClass *krn;
 
-  krn = mrb->kernel_module = mrb_define_module(mrb, "Kernel");                                                    /* 15.3.1 */
+  mrb->kernel_module = krn = mrb_define_module(mrb, "Kernel");                                                    /* 15.3.1 */
   mrb_define_class_method(mrb, krn, "block_given?",         mrb_f_block_given_p_m,           MRB_ARGS_NONE());    /* 15.3.1.2.2  */
   mrb_define_class_method(mrb, krn, "global_variables",     mrb_f_global_variables,          MRB_ARGS_NONE());    /* 15.3.1.2.4  */
   mrb_define_class_method(mrb, krn, "iterator?",            mrb_f_block_given_p_m,           MRB_ARGS_NONE());    /* 15.3.1.2.5  */

src/numeric.c

@@ -1161,7 +1161,7 @@ mrb_init_numeric(mrb_state *mrb)
   mrb_define_method(mrb, integer, "to_int", int_to_i, MRB_ARGS_NONE());
 
   /* Fixnum Class */
-  fixnum = mrb->fixnum_class = mrb_define_class(mrb, "Fixnum", integer);
+  mrb->fixnum_class = fixnum = mrb_define_class(mrb, "Fixnum", integer);
   mrb_define_method(mrb, fixnum,  "+",        fix_plus,          MRB_ARGS_REQ(1)); /* 15.2.8.3.1  */
   mrb_define_method(mrb, fixnum,  "-",        fix_minus,         MRB_ARGS_REQ(1)); /* 15.2.8.3.2  */
   mrb_define_method(mrb, fixnum,  "*",        fix_mul,           MRB_ARGS_REQ(1)); /* 15.2.8.3.3  */
@@ -1181,7 +1181,7 @@ mrb_init_numeric(mrb_state *mrb)
   mrb_define_method(mrb, fixnum,  "divmod",   fix_divmod,        MRB_ARGS_REQ(1)); /* 15.2.8.3.30 (x) */
 
   /* Float Class */
-  fl = mrb->float_class = mrb_define_class(mrb, "Float", numeric);                 /* 15.2.9 */
+  mrb->float_class = fl = mrb_define_class(mrb, "Float", numeric);                 /* 15.2.9 */
   mrb_undef_class_method(mrb,  fl, "new");
   mrb_define_method(mrb, fl,      "+",         flo_plus,         MRB_ARGS_REQ(1)); /* 15.2.9.3.1  */
   mrb_define_method(mrb, fl,      "-",         flo_minus,        MRB_ARGS_REQ(1)); /* 15.2.9.3.2  */

src/object.c

@@ -264,7 +264,7 @@ mrb_init_object(mrb_state *mrb)
   struct RClass *t;
   struct RClass *f;
 
-  n = mrb->nil_class   = mrb_define_class(mrb, "NilClass",   mrb->object_class);
+  mrb->nil_class   = n = mrb_define_class(mrb, "NilClass",   mrb->object_class);
   mrb_undef_class_method(mrb, n, "new");
   mrb_define_method(mrb, n, "&",    false_and,      MRB_ARGS_REQ(1));  /* 15.2.4.3.1  */
   mrb_define_method(mrb, n, "^",    false_xor,      MRB_ARGS_REQ(1));  /* 15.2.4.3.2  */
@@ -273,7 +273,7 @@ mrb_init_object(mrb_state *mrb)
   mrb_define_method(mrb, n, "to_s", nil_to_s,       MRB_ARGS_NONE());  /* 15.2.4.3.5  */
   mrb_define_method(mrb, n, "inspect", nil_inspect, MRB_ARGS_NONE());
 
-  t = mrb->true_class  = mrb_define_class(mrb, "TrueClass",  mrb->object_class);
+  mrb->true_class  = t = mrb_define_class(mrb, "TrueClass",  mrb->object_class);
   mrb_undef_class_method(mrb, t, "new");
   mrb_define_method(mrb, t, "&",    true_and,       MRB_ARGS_REQ(1));  /* 15.2.5.3.1  */
   mrb_define_method(mrb, t, "^",    true_xor,       MRB_ARGS_REQ(1));  /* 15.2.5.3.2  */
@@ -281,7 +281,7 @@ mrb_init_object(mrb_state *mrb)
   mrb_define_method(mrb, t, "|",    true_or,        MRB_ARGS_REQ(1));  /* 15.2.5.3.4  */
   mrb_define_method(mrb, t, "inspect", true_to_s,   MRB_ARGS_NONE());
 
-  f = mrb->false_class = mrb_define_class(mrb, "FalseClass", mrb->object_class);
+  mrb->false_class = f = mrb_define_class(mrb, "FalseClass", mrb->object_class);
   mrb_undef_class_method(mrb, f, "new");
   mrb_define_method(mrb, f, "&",    false_and,      MRB_ARGS_REQ(1));  /* 15.2.6.3.1  */
   mrb_define_method(mrb, f, "^",    false_xor,      MRB_ARGS_REQ(1));  /* 15.2.6.3.2  */

src/string.c

@@ -2674,7 +2674,7 @@ mrb_init_string(mrb_state *mrb)
 
   mrb_static_assert(RSTRING_EMBED_LEN_MAX < (1 << 5), "pointer size too big for embedded string");
 
-  s = mrb->string_class = mrb_define_class(mrb, "String", mrb->object_class);             /* 15.2.10 */
+  mrb->string_class = s = mrb_define_class(mrb, "String", mrb->object_class);             /* 15.2.10 */
   MRB_SET_INSTANCE_TT(s, MRB_TT_STRING);
 
   mrb_define_method(mrb, s, "bytesize",        mrb_str_bytesize,        MRB_ARGS_NONE());

src/symbol.c

@@ -478,7 +478,7 @@ mrb_init_symbol(mrb_state *mrb)
 {
   struct RClass *sym;
 
-  sym = mrb->symbol_class = mrb_define_class(mrb, "Symbol", mrb->object_class);                 /* 15.2.11 */
+  mrb->symbol_class = sym = mrb_define_class(mrb, "Symbol", mrb->object_class);                 /* 15.2.11 */
 
   mrb_define_method(mrb, sym, "===",             sym_equal,      MRB_ARGS_REQ(1));              /* 15.2.11.3.1  */
   mrb_define_method(mrb, sym, "id2name",         mrb_sym_to_s,   MRB_ARGS_NONE());              /* 15.2.11.3.2  */