Adding column names functionality

src/esqlite3.erl

@@ -71,7 +71,8 @@ foreach(F, Sql, Connection) ->
 %%
 foreach_s(F, Statement) ->    
     case try_step(Statement, 0) of
-	'$done' -> ok;
+	'$done' -> 
+	    ok;
 	Row when is_tuple(Row) ->
 	    F(Row),
 	    foreach_s(F, Statement)
@@ -82,7 +83,7 @@ map_s(F, Statement) ->
     case try_step(Statement, 0) of
 	'$done' ->
 	    [];
-	Row -> 
+	Row when is_tuple(Row) -> 
 	    [F(Row) | map_s(F, Statement)]
     end.
 
@@ -95,11 +96,13 @@ do_steps(Statement) ->
 	    [Row | do_steps(Statement)]
     end.  
 
+%% Try the step, when the database is busy, 
 try_step(_Statement, Tries) when Tries > 5 ->
     throw(too_many_tries);
 try_step(Statement, Tries) ->
     case esqlite3:step(Statement) of
 	'$busy' -> 
+	    timer:sleep(100 * Tries),
 	    try_step(Statement, Tries + 1);
 	Something -> 
 	    Something

src/esqlite3_nif.erl

@@ -27,6 +27,7 @@
 	 prepare/4,
 	 step/3,
 	 bind/4,
+	 column_names/3,
 	 close/3
 ]).
 
@@ -70,16 +71,22 @@ prepare(_Db, _Ref, _Dest, _Sql) ->
 
 %% @doc
 %%
-%% @spec step(connection(), reference(), pid()) -> ok | {error, message()}
+%% @spec step(statement(), reference(), pid()) -> ok | {error, message()}
 step(_Stmt, _Ref, _Dest) ->
     exit(nif_library_not_loaded).
 
 %% @doc Bind parameters to a prepared statement. 
 %%
-%% @spec bind(connection(), reference(), pid(), []) -> ok | {error, message()} 
+%% @spec bind(statement(), reference(), pid(), []) -> ok | {error, message()} 
 bind(_Stmt, _Ref, _Dest, _Args) ->
     exit(nif_library_not_loaded).
 
+%% @doc Retrieve the column names of the prepared statement
+%%
+%% @spec column_names(statement(), reference(), pid()) -> {ok, tuple()} | {error, message()} 
+column_names(_Stmt, _Ref, _Dest) ->
+    exit(nif_library_not_loaded).
+
 %% @doc Close the connection.
 %%
 %% @spec close(connection(), reference(), pid()) -> ok | {error, message()}