Add poc files

h_program-lang/big_grep.mli

@@ -0,0 +1,27 @@
+
+type index = {
+  big_string: string;
+  pos_to_entity: (int, Database_code.entity) Hashtbl.t;
+  case_sensitive: bool;
+}
+val empty_index: unit -> index
+
+(* the list is supposed to be sorted by importance so that the
+ * top n search returns first the most important entities
+ *)
+val build_index: 
+  ?case_sensitive:bool ->
+  Database_code.entity list -> index
+
+val top_n_search: 
+  top_n:int ->
+  query:string -> 
+  index -> 
+  Database_code.entity list
+
+val naive_top_n_search:
+  top_n:int ->
+  query:string -> 
+  Database_code.entity list ->
+  Database_code.entity list
+