2 files changed, 11 insertions, 1 deletions
diff --git a/nerv.c b/nerv.c
index d586867..0bc661e 100644
--- a/nerv.c
+++ b/nerv.c
@@ -17,8 +17,18 @@ void nerv_utils_init(lua_State *L) {
 
 int luaopen_libnerv(lua_State *L) {
     lua_newtable(L);
+    /* duplicate table */
     lua_pushvalue(L, -1);
+    /* set table to global index */
     lua_setfield(L, LUA_GLOBALSINDEX, "nerv");
+    /* A table reference still remains.
+     *
+     * The following initialization functions should obey to the rule that they
+     * maintain the stack properly to guarantee the stack stays the same before
+     * and after invoking the call (i.e. stay balanced).
+     *
+     * Also note that they can make use of the value at top of the stack which
+     * references to the `nerv` global table. */
     nerv_utils_init(L);
     nerv_point_init(L);
     nerv_matrix_init(L);
diff --git a/nerv.lua b/nerv.lua
index 1c4ba39..d7f7e91 100644
--- a/nerv.lua
+++ b/nerv.lua
@@ -1,7 +1,6 @@
 require 'libnerv'
 require 'matrix.init'
 require 'io.init'
--- nerv.class = require 'pl.class'
 nerv.utils = require 'pl.utils'
 
 function nerv.error(fmt, ...)
@@ -12,6 +11,7 @@ function nerv.error_method_not_implement()
     nerv.error("method not implemented");
 end
 
+-- Torch C API wrapper
 function nerv.class(tname, parenttname)
 
    local function constructor(...)