diff --git a/include/compiler/treeifier/ast.hh b/include/compiler/treeifier/ast.hh
index e1ecd3d..6842d6d 100644
--- a/include/compiler/treeifier/ast.hh
+++ b/include/compiler/treeifier/ast.hh
@@ -2,6 +2,7 @@
 
 #include <string>
 #include <set>
+#include <map>
 #include <unordered_map>
 #include <memory>
 #include "compiler/treeifier/tokenizer.hh"
@@ -56,6 +57,7 @@ namespace ppc::comp::tree::ast {
 
         void add_parser(const parser_t *parser);
         void add_parser(const parser_t *parser, const std::string &group);
+        void add_parser(const parser_t *parser, const std::string &group, const namespace_name_t &name);
         void add_group(const std::string &name);
 
         void add_parser(parser_adder_t factory) { factory(*this); }
@@ -107,7 +109,7 @@ namespace ppc::comp::tree::ast {
 
     class group_parser_t : public parser_t {
     private:
-        std::vector<std::pair<lang::namespace_name_t, const parser_t*>> named_parsers;
+        std::map<lang::namespace_name_t, const parser_t*> named_parsers;
         std::vector<const parser_t*> parsers;
     public:
         group_parser_t &add(const parser_t &parser);
diff --git a/include/lang/common.hh b/include/lang/common.hh
index b846bf8..6d193c8 100644
--- a/include/lang/common.hh
+++ b/include/lang/common.hh
@@ -32,8 +32,14 @@ namespace ppc::lang {
     struct namespace_name_t : public std::vector<std::string> {
         using base = std::vector<std::string>;
 
-        bool operator ==(const namespace_name_t &other)  const;
-        bool operator !=(const namespace_name_t &other)  const;
+        int compare(const namespace_name_t &other) const;
+
+        bool operator==(const namespace_name_t &other) const { return compare(other) == 0; }
+        bool operator!=(const namespace_name_t &other) const { return compare(other) != 0; }
+        bool operator<(const namespace_name_t &other) const { return compare(other) < 0; }
+        bool operator<=(const namespace_name_t &other) const { return compare(other) <= 0; }
+        bool operator>(const namespace_name_t &other) const  { return compare(other) > 0; }
+        bool operator>=(const namespace_name_t &other) const { return compare(other) >= 0; }
 
         operator std::string() const { return to_string(); }
         std::string to_string() const;
@@ -45,10 +51,16 @@ namespace ppc::lang {
     struct loc_namespace_name_t : public std::vector<located_t<std::string>> {
         using base = std::vector<located_t<std::string>>;
 
-        bool operator ==(const loc_namespace_name_t &other) const;
-        bool operator !=(const loc_namespace_name_t &other) const;
+        int compare(const loc_namespace_name_t &other) const;
 
-        namespace_name_t strip_location();
+        bool operator==(const loc_namespace_name_t &other) const { return compare(other) == 0; }
+        bool operator!=(const loc_namespace_name_t &other) const { return compare(other) != 0; }
+        bool operator<(const loc_namespace_name_t &other) const { return compare(other) < 0; }
+        bool operator<=(const loc_namespace_name_t &other) const { return compare(other) <= 0; }
+        bool operator>(const loc_namespace_name_t &other) const  { return compare(other) > 0; }
+        bool operator>=(const loc_namespace_name_t &other) const { return compare(other) >= 0; }
+
+        namespace_name_t strip_location() const;
 
         operator std::string() const { return to_string(); }
         std::string to_string() const;
diff --git a/src/compiler/treeifier/ast.cc b/src/compiler/treeifier/ast.cc
index aca1368..e0e66b8 100644
--- a/src/compiler/treeifier/ast.cc
+++ b/src/compiler/treeifier/ast.cc
@@ -28,6 +28,10 @@ namespace ppc::comp::tree::ast {
         add_parser(parser);
         this->group[group].add(*parser);
     }
+    void ast_ctx_t::add_parser(const parser_t *parser, const std::string &group, const namespace_name_t &name) {
+        add_parser(parser);
+        this->group[group].add(*parser, name);
+    }
     void ast_ctx_t::add_group(const std::string &name) {
         auto parser = new group_parser_t(name);
         if (parsers.find(parser->name()) != parsers.end()) throw "The parser '" + parser->name() + "' already exists.";
diff --git a/src/compiler/treeifier/ast/parsers/group.cc b/src/compiler/treeifier/ast/parsers/group.cc
index 7e19636..c52d103 100644
--- a/src/compiler/treeifier/ast/parsers/group.cc
+++ b/src/compiler/treeifier/ast/parsers/group.cc
@@ -10,26 +10,34 @@ using namespace ppc::comp::tree::ast;
 using namespace std::string_literals;
 using namespace std;
 
-static bool read_nmsp(ast_ctx_t &ctx, size_t &i, const lang::namespace_name_t &name) {
+static bool read_nmsp(ast_ctx_t &ctx, size_t &i, lang::loc_namespace_name_t &name) {
     tree_helper_t h(ctx, i);
-
-    size_t equal_i = 0;
-
-    while (true) {
-        if (h.ended()) break;
-        if (equal_i >= name.size()) return false;
-        auto &curr = h.curr();
-        if (!curr.is_identifier()) return false;
-
-        if (name[equal_i] != curr.identifier()) return false;
-
-        if (h.try_advance() && h.curr().is_operator(operator_t::DOUBLE_COLON)) {
-            equal_i++;
+    map_t res;
+    if (!h.parse("$_nmsp", res)) return false;
+    name = conv::map_to_nmsp(res);
+    return true;
+}
+template <class T>
+static bool resolve_nmsp(ast_ctx_t &ctx, const lang::namespace_name_t &name, T begin, T end, lang::namespace_name_t &actual_name) {
+    for (auto it = begin; it != end; it++) {
+        const namespace_name_t &curr = it->first;
+        if (curr == name) {
+            actual_name = name;
+            return true;
         }
-        else break;
     }
-
-    return equal_i != name.size();
+    for (const auto &import : ctx.imports) {
+        auto new_name = name;
+        new_name.insert(new_name.begin(), import.begin(), import.end());
+        for (auto it = begin; it != end; it++) {
+            const namespace_name_t &curr = it->first;
+            if (curr == new_name) {
+                actual_name = name;
+                return true;
+            }
+        }
+    }
+    return false;
 }
 
 
@@ -38,11 +46,14 @@ bool group_parser_t::parse(ast_ctx_t &ctx, size_t &i, data::map_t &out) const {
 
     if (h.ended()) return false;
 
-    for (auto &pair : named_parsers) {
-        if (!read_nmsp(ctx, i, pair.first)) continue;
-        auto &parser = *pair.second;
-        if (parser(ctx, i, out)) return true;
-        else throw message_t::error("Unexpected construct specifier.", h.res_loc());
+    loc_namespace_name_t name;
+    if (read_nmsp(ctx, h.i, name)) {
+        namespace_name_t actual;
+        if (resolve_nmsp(ctx, name.strip_location(), named_parsers.begin(), named_parsers.end(), actual)) {
+            auto &parser = *this->named_parsers.find(actual)->second;
+            if (parser(ctx, i, out)) return true;
+            else throw message_t::error("Unexpected construct specifier.", h.res_loc());
+        }
     }
 
     unordered_map<string, message_t> errors;
@@ -66,7 +77,7 @@ group_parser_t &group_parser_t::add(const parser_t &parser, const lang::namespac
         throw "Parser '" + name.to_string() + "' already in group.";
     }
 
-    named_parsers.push_back({ name, &parser });
+    named_parsers[name] = &parser;
 
     return *this;
 }
diff --git a/src/lang/common.cc b/src/lang/common.cc
index 36f1e8a..bf4bd70 100644
--- a/src/lang/common.cc
+++ b/src/lang/common.cc
@@ -23,46 +23,31 @@ namespace ppc::lang {
 
         return res.str();
     }
-    
-    bool loc_namespace_name_t::operator==(const loc_namespace_name_t &other) const {
-        if (other.size() != size()) return false;
 
-        for (size_t i = 0; i < size(); i++) {
-            if (other[i] != (*this)[i]) return false;
+    int namespace_name_t::compare(const namespace_name_t &b) const {
+        const auto &a = *this;
+        for (size_t i = 0; i < a.size() && i < b.size(); i++) {
+            auto cmp = a[i].compare(b[i]);
+            if (cmp != 0) return cmp;
         }
 
-        return true;
+        if (a.size() > b.size()) return 1;
+        else if (a.size() == b.size()) return 0;
+        else return -1;
     }
-    bool loc_namespace_name_t::operator!=(const loc_namespace_name_t &other) const {
-        if (other.size() != size()) return true;
-
-        for (size_t i = 0; i < size(); i++) {
-            if (other[i] == (*this)[i]) return false;
+    int loc_namespace_name_t::compare(const loc_namespace_name_t &b) const {
+        const auto &a = *this;
+        for (size_t i = 0; i < a.size() && i < b.size(); i++) {
+            auto cmp = a[i].compare(b[i]);
+            if (cmp != 0) return cmp;
         }
 
-        return true;
+        if (a.size() > b.size()) return 1;
+        else if (a.size() == b.size()) return 0;
+        else return -1;
     }
 
-    bool namespace_name_t::operator==(const namespace_name_t &other) const {
-        if (other.size() != size()) return false;
-
-        for (size_t i = 0; i < size(); i++) {
-            if (other[i] != (*this)[i]) return false;
-        }
-
-        return true;
-    }
-    bool namespace_name_t::operator!=(const namespace_name_t &other) const {
-        if (other.size() != size()) return true;
-
-        for (size_t i = 0; i < size(); i++) {
-            if (other[i] == (*this)[i]) return false;
-        }
-
-        return true;
-    }
-
-    namespace_name_t loc_namespace_name_t::strip_location() {
+    namespace_name_t loc_namespace_name_t::strip_location() const {
         namespace_name_t res;
 
         for (const auto &el : *this) {
@@ -71,6 +56,5 @@ namespace ppc::lang {
 
         return res;
     }
-
 }