modules/system: Split helpers header into smaller bits

There is a very good reason for this, I think...

modules/system/include/moon/mrb/helpers.hxx

@@ -1,40 +1,9 @@
 #ifndef MOON_MRB_HELPERS
 #define MOON_MRB_HELPERS
 
-#include <mruby.h>
-#include <mruby/data.h>
-#include <mruby/string.h>
-#include <mruby/variable.h>
+#include "moon/mrb/helpers/class.hxx"
+#include "moon/mrb/helpers/variable.hxx"
+#include "moon/mrb/helpers/error.hxx"
+#include "moon/mrb/helpers/data.hxx"
 
-#define IVget(_name_) mrb_iv_get(mrb, self, mrb_intern_lit(mrb, _name_))
-#define IVset(_name_, _value_) mrb_iv_set(mrb, self, mrb_intern_lit(mrb, _name_), _value_)
-
-#define KEY_SHADER "@shader"
-#define KEY_VBO "@vbo"
-#define KEY_ORIGIN "@origin"
-
-#define MOON_GET_CLASS(__name__) mrb_class_get_under(mrb, mrb_module_get(mrb, "Moon"), __name__)
-#define MOON_GET_MODULE(__name__) mrb_module_get_under(mrb, mrb_module_get(mrb, "Moon"), __name__)
-;
-
-static inline mrb_value
-moon_iv_get(mrb_state *mrb, mrb_value self, const char *name)
-{
-  mrb_value iv_value = mrb_iv_get(mrb, self, mrb_intern_cstr(mrb, name));
-  if (mrb_nil_p(iv_value)) {
-    mrb_raisef(mrb, E_ARGUMENT_ERROR, "Cannot use a nil %S", mrb_str_new_cstr(mrb, name));
-  }
-  return iv_value;
-}
-
-static inline void
-moon_data_cleanup(mrb_state *mrb, mrb_value self)
-{
-  void *ptr = DATA_PTR(self);
-  const struct mrb_data_type* type = DATA_TYPE(self);
-  if (ptr && type) {
-    type->dfree(mrb, ptr);
-  }
-  DATA_PTR(self) = NULL;
-}
 #endif

modules/system/include/moon/mrb/helpers/class.hxx

@@ -0,0 +1,10 @@
+#ifndef MOON_MRB_CLASS_HELPERS
+#define MOON_MRB_CLASS_HELPERS
+
+#include <mruby.h>
+#include <mruby/class.h>
+
+#define MOON_GET_CLASS(__name__) mrb_class_get_under(mrb, mrb_module_get(mrb, "Moon"), __name__)
+#define MOON_GET_MODULE(__name__) mrb_module_get_under(mrb, mrb_module_get(mrb, "Moon"), __name__)
+
+#endif

modules/system/include/moon/mrb/helpers/data.hxx

@@ -0,0 +1,18 @@
+#ifndef MOON_MRB_DATA_HELPERS
+#define MOON_MRB_DATA_HELPERS
+
+#include <mruby.h>
+#include <mruby/data.h>
+
+static inline void
+moon_data_cleanup(mrb_state* mrb, mrb_value self)
+{
+  void *ptr = DATA_PTR(self);
+  const struct mrb_data_type* type = DATA_TYPE(self);
+  if (ptr && type) {
+    type->dfree(mrb, ptr);
+  }
+  DATA_PTR(self) = NULL;
+}
+
+#endif

modules/system/include/moon/mrb/helpers/error.hxx

@@ -0,0 +1,8 @@
+#ifndef MOON_MRB_ERROR_HELPERS
+#define MOON_MRB_ERROR_HELPERS
+
+#include "moon/mrb/helpers/class.hxx"
+
+#define MOON_E_FILE_NOT_FOUND MOON_GET_CLASS("FileNotFoundError")
+
+#endif

modules/system/include/moon/mrb/helpers/variable.hxx

@@ -0,0 +1,23 @@
+#ifndef MOON_MRB_VARIABLE_HELPERS
+#define MOON_MRB_VARIABLE_HELPERS
+
+#include <mruby.h>
+#include <mruby/variable.h>
+#include <mruby/string.h>
+
+#define IVget(_name_) mrb_iv_get(mrb, self, mrb_intern_lit(mrb, _name_))
+#define IVset(_name_, _value_) mrb_iv_set(mrb, self, mrb_intern_lit(mrb, _name_), _value_)
+
+static inline mrb_value
+moon_iv_get(mrb_state* mrb, mrb_value self, const char* name)
+{
+  mrb_value iv_value = mrb_iv_get(mrb, self, mrb_intern_cstr(mrb, name));
+  if (mrb_nil_p(iv_value)) {
+    mrb_raisef(mrb, E_ARGUMENT_ERROR, "Cannot use a nil %S", mrb_str_new_cstr(mrb, name));
+  }
+  return iv_value;
+}
+
+#define KEY_VBO "@vbo"
+
+#endif

modules/system/include/moon/mrb_err.hxx

@@ -6,6 +6,6 @@
 #include <mruby/class.h>
 #include <mruby/value.h>
 
-extern bool mmrb_check_class(mrb_state *mrb, mrb_value obj, struct RClass *klass, bool quiet);
+extern bool mmrb_check_class(mrb_state *mrb, mrb_value obj, struct RClass* klass, bool quiet);
 
 #endif

modules/system/mrblib/file_not_found_error.rb

@@ -0,0 +1,5 @@
+module Moon
+  # Error raised when a resource cannot be found on disk
+  class FileNotFoundError < RuntimeError
+  end
+end