diff --git a/lang/builders/include/builders_utils.hpp b/lang/builders/include/builders_utils.hpp
index 7323cab..7cf3022 100644
--- a/lang/builders/include/builders_utils.hpp
+++ b/lang/builders/include/builders_utils.hpp
@@ -13,6 +13,8 @@ using Names = names::NameTree;
 
 using Executor = utils::Executor<Exprs, Types, Names>;
 
+using ParserNode = parser::ParseTree::Node;
+
 using Node = nodes::Node_<nodes::NodePart<utils::Pos>>; // TODO
 
 template <typename N>
diff --git a/lang/builders/include/expression_builders.hpp b/lang/builders/include/expression_builders.hpp
index 5a52b6a..1e9614e 100644
--- a/lang/builders/include/expression_builders.hpp
+++ b/lang/builders/include/expression_builders.hpp
@@ -28,7 +28,7 @@ struct BuilderTask<nodes::ExpressionProxy>
     : public BuilderTaskBase<nodes::ExpressionProxy> {
   using BuilderTaskBase<nodes::ExpressionProxy>::BuilderTaskBase;
 
-  nodes::ExpressionProxy operator()(const parser::ParseTree::Node &parser_node,
+  nodes::ExpressionProxy operator()(const ParserNode &parser_node,
                                     const utils::None &args) override;
 };
 
@@ -37,7 +37,7 @@ struct BuilderTask<nodes::Match::Case>
     : public BuilderTaskBase<nodes::Match::Case> {
   using BuilderTaskBase<nodes::Match::Case>::BuilderTaskBase;
 
-  nodes::Match::Case operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Match::Case operator()(const ParserNode &parser_node,
                                 const utils::None &args) override;
 };
 
@@ -45,7 +45,7 @@ template <>
 struct BuilderTask<nodes::Match> : public BuilderTaskBase<nodes::Match> {
   using BuilderTaskBase<nodes::Match>::BuilderTaskBase;
 
-  nodes::Match operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Match operator()(const ParserNode &parser_node,
                           const utils::None &args) override;
 };
 
@@ -54,7 +54,7 @@ struct BuilderTask<nodes::Condition>
     : public BuilderTaskBase<nodes::Condition> {
   using BuilderTaskBase<nodes::Condition>::BuilderTaskBase;
 
-  nodes::Condition operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Condition operator()(const ParserNode &parser_node,
                               const utils::None &args) override;
 };
 
@@ -62,7 +62,7 @@ template <>
 struct BuilderTask<nodes::Loop> : public BuilderTaskBase<nodes::Loop> {
   using BuilderTaskBase<nodes::Loop>::BuilderTaskBase;
 
-  nodes::Loop operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Loop operator()(const ParserNode &parser_node,
                          const utils::None &args) override;
 };
 
@@ -73,7 +73,7 @@ struct BuilderTask<nodes::NameExpression, utils::CommaTag>
     : public BuilderTaskBase<nodes::NameExpression> {
   using BuilderTaskBase<nodes::NameExpression>::BuilderTaskBase;
 
-  nodes::NameExpression operator()(const parser::ParseTree::Node &parser_node,
+  nodes::NameExpression operator()(const ParserNode &parser_node,
                                    const utils::None &args) override;
 };
 
@@ -82,7 +82,7 @@ struct BuilderTask<nodes::NameExpression, utils::OperatorTag>
     : public BuilderTaskBase<nodes::NameExpression> {
   using BuilderTaskBase<nodes::NameExpression>::BuilderTaskBase;
 
-  nodes::NameExpression operator()(const parser::ParseTree::Node &parser_node,
+  nodes::NameExpression operator()(const ParserNode &parser_node,
                                    const utils::None &args) override;
 };
 
@@ -98,7 +98,7 @@ struct BuilderTask<nodes::Container, T>
   // '{' (expression ';')* '}'
   // or
   // '[[' expression+ ']]'
-  nodes::Container operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Container operator()(const ParserNode &parser_node,
                               const utils::None &) override {
     const auto container_type = std::is_same_v<T, utils::BlockTag>
                                     ? nodes::Container::BLOCK
@@ -124,7 +124,7 @@ template <>
 struct BuilderTask<nodes::Return> : public BuilderTaskBase<nodes::Return> {
   using BuilderTaskBase<nodes::Return>::BuilderTaskBase;
 
-  nodes::Return operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Return operator()(const ParserNode &parser_node,
                            const utils::None &args) override;
 };
 
@@ -133,7 +133,7 @@ struct BuilderTask<nodes::NameDefinition>
     : public BuilderTaskBase<nodes::NameDefinition> {
   using BuilderTaskBase<nodes::NameDefinition>::BuilderTaskBase;
 
-  nodes::NameDefinition operator()(const parser::ParseTree::Node &parser_node,
+  nodes::NameDefinition operator()(const ParserNode &parser_node,
                                    const utils::None &args) override;
 };
 
@@ -142,7 +142,7 @@ struct BuilderTask<nodes::Access, utils::ArrayAccessTag>
     : public BuilderTaskBase<nodes::Access> {
   using BuilderTaskBase<nodes::Access>::BuilderTaskBase;
 
-  nodes::Access operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Access operator()(const ParserNode &parser_node,
                            const utils::None &args) override;
 };
 
@@ -151,7 +151,7 @@ struct BuilderTask<nodes::Access, utils::TupleAccessTag>
     : public BuilderTaskBase<nodes::Access> {
   using BuilderTaskBase<nodes::Access>::BuilderTaskBase;
 
-  nodes::Access operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Access operator()(const ParserNode &parser_node,
                            const utils::None &args) override;
 };
 
@@ -160,7 +160,7 @@ struct BuilderTask<nodes::LoopControl>
     : public BuilderTaskBase<nodes::LoopControl> {
   using BuilderTaskBase<nodes::LoopControl>::BuilderTaskBase;
 
-  nodes::LoopControl operator()(const parser::ParseTree::Node &parser_node,
+  nodes::LoopControl operator()(const ParserNode &parser_node,
                                 const utils::None &args) override;
 };
 
@@ -169,9 +169,8 @@ struct BuilderTask<nodes::ModifierExpression, utils::RefTag>
     : public BuilderTaskBase<nodes::ModifierExpression> {
   using BuilderTaskBase<nodes::ModifierExpression>::BuilderTaskBase;
 
-  nodes::ModifierExpression
-  operator()(const parser::ParseTree::Node &parser_node,
-             const utils::None &args) override;
+  nodes::ModifierExpression operator()(const ParserNode &parser_node,
+                                       const utils::None &args) override;
 };
 
 template <>
@@ -179,9 +178,8 @@ struct BuilderTask<nodes::ModifierExpression, utils::SuffixTag>
     : public BuilderTaskBase<nodes::ModifierExpression> {
   using BuilderTaskBase<nodes::ModifierExpression>::BuilderTaskBase;
 
-  nodes::ModifierExpression
-  operator()(const parser::ParseTree::Node &parser_node,
-             const utils::None &args) override;
+  nodes::ModifierExpression operator()(const ParserNode &parser_node,
+                                       const utils::None &args) override;
 };
 
 template <typename T>
@@ -194,9 +192,8 @@ struct BuilderTask<nodes::ModifierExpression, T>
   // _reference_ expression
   // or
   // expression ('?' | '!')
-  nodes::ModifierExpression
-  operator()(const parser::ParseTree::Node &parser_node,
-             const utils::None &) override {
+  nodes::ModifierExpression operator()(const ParserNode &parser_node,
+                                       const utils::None &) override {
     const size_t modifier_pos =
         std::is_same_v<T, utils::RefTag> ? 0 : parser_node.child_count() - 1;
 
@@ -214,7 +211,7 @@ struct BuilderTask<nodes::NameExpression, utils::FuncCallTag>
     : public BuilderTaskBase<nodes::NameExpression> {
   using BuilderTaskBase<nodes::NameExpression>::BuilderTaskBase;
 
-  nodes::NameExpression operator()(const parser::ParseTree::Node &parser_node,
+  nodes::NameExpression operator()(const ParserNode &parser_node,
                                    const utils::None &args) override;
 };
 
@@ -223,7 +220,7 @@ struct BuilderTask<nodes::Constructor>
     : public BuilderTaskBase<nodes::Constructor> {
   using BuilderTaskBase<nodes::Constructor>::BuilderTaskBase;
 
-  nodes::Constructor operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Constructor operator()(const ParserNode &parser_node,
                                 const utils::None &args) override;
 };
 
@@ -231,7 +228,7 @@ template <>
 struct BuilderTask<nodes::Lambda> : public BuilderTaskBase<nodes::Lambda> {
   using BuilderTaskBase<nodes::Lambda>::BuilderTaskBase;
 
-  nodes::Lambda operator()(const parser::ParseTree::Node &parser_node,
+  nodes::Lambda operator()(const ParserNode &parser_node,
                            const utils::None &args) override;
 };
 
diff --git a/lang/builders/src/expression_builders.cpp b/lang/builders/src/expression_builders.cpp
index 65f6175..42d33b3 100644
--- a/lang/builders/src/expression_builders.cpp
+++ b/lang/builders/src/expression_builders.cpp
@@ -10,8 +10,9 @@
 
 namespace builders {
 
-nodes::ExpressionProxy BuilderTask<nodes::ExpressionProxy>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::ExpressionProxy
+BuilderTask<nodes::ExpressionProxy>::operator()(const ParserNode &parser_node,
+                                                const utils::None &) {
   tokens::Type type = tokens::string_to_type(parser_node.get_type());
 
   auto maybe_parenthesis = parser_node.previous_sibling();
@@ -19,150 +20,141 @@ nodes::ExpressionProxy BuilderTask<nodes::ExpressionProxy>::operator()(
       (!maybe_parenthesis.is_null() && !maybe_parenthesis.is_named() &&
        maybe_parenthesis.get_value() == "(");
 
+  std::optional<nodes::Expression::Type> expr;
   switch (type) {
   // --- flow control
   case tokens::Type::MATCH:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), Run<nodes::Match>(parser_node), is_scoped));
+    expr = Run<nodes::Match>(parser_node);
+    break;
   case tokens::Type::CONDITION:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          Run<nodes::Condition>(parser_node), is_scoped));
+    return state<Exprs>().add_expression({build_node(parser_node),
+                                          Run<nodes::Condition>(parser_node),
+                                          is_scoped});
+    expr = Run<nodes::Match>(parser_node);
+    break;
   case tokens::Type::LOOP:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), Run<nodes::Loop>(parser_node), is_scoped));
+    return state<Exprs>().add_expression(
+        {build_node(parser_node), Run<nodes::Loop>(parser_node), is_scoped});
+    expr = Run<nodes::Match>(parser_node);
+    break;
   // --- operators
   case tokens::Type::COMMA_EXPRESSION:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::NameExpression, utils::CommaTag>(parser_node), is_scoped));
+    expr = Run<nodes::NameExpression, utils::CommaTag>(parser_node);
+    break;
   case tokens::Type::OPERATOR_EXPRESSION:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::NameExpression, utils::OperatorTag>(parser_node),
-        is_scoped));
+    expr = Run<nodes::NameExpression, utils::OperatorTag>(parser_node);
+    break;
   // --- containers
   case tokens::Type::BLOCK:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::Container, utils::BlockTag>(parser_node), is_scoped));
+    expr = Run<nodes::Container, utils::BlockTag>(parser_node);
+    break;
   case tokens::Type::ARRAY:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::Container, utils::ArrayTag>(parser_node), is_scoped));
+    expr = Run<nodes::Container, utils::ArrayTag>(parser_node);
+    break;
   // --- modifiers
   case tokens::Type::RETURN:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), Run<nodes::Return>(parser_node), is_scoped));
+    expr = Run<nodes::Return>(parser_node);
+    break;
   case tokens::Type::NAME_DEFINITION:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          Run<nodes::NameDefinition>(parser_node), is_scoped));
+    expr = Run<nodes::NameDefinition>(parser_node);
+    break;
   case tokens::Type::ARRAY_ACCESS:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::Access, utils::ArrayAccessTag>(parser_node), is_scoped));
+    expr = Run<nodes::Access, utils::ArrayAccessTag>(parser_node);
+    break;
   case tokens::Type::TUPLE_ACCESS:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::Access, utils::TupleAccessTag>(parser_node), is_scoped));
+    expr = Run<nodes::Access, utils::TupleAccessTag>(parser_node);
+    break;
   case tokens::Type::LOOP_CONTROL:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          Run<nodes::LoopControl>(parser_node), is_scoped));
+    expr = Run<nodes::LoopControl>(parser_node);
+    break;
   case tokens::Type::REFERENCE_EXPRESSION:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::ModifierExpression, utils::RefTag>(parser_node), is_scoped));
+    expr = Run<nodes::ModifierExpression, utils::RefTag>(parser_node);
+    break;
   case tokens::Type::SUFFIX_EXPRESSION:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::ModifierExpression, utils::SuffixTag>(parser_node),
-        is_scoped));
+    expr = Run<nodes::ModifierExpression, utils::SuffixTag>(parser_node);
+    break;
   // --- other
   case tokens::Type::NAME_EXPRESSION:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node),
-        Run<nodes::NameExpression, utils::FuncCallTag>(parser_node),
-        is_scoped));
+    expr = Run<nodes::NameExpression, utils::FuncCallTag>(parser_node);
+    break;
   case tokens::Type::ARGUMENT_NAME_IDENTIFIER:
   case tokens::Type::SIMPLE_NAME_IDENTIFIER:
   case tokens::Type::PLACEHOLDER:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          nodes::NameExpression(build_node(parser_node),
-                                                build_identifier(parser_node)),
-                          is_scoped));
+    expr = nodes::NameExpression(build_node(parser_node),
+                                 build_identifier(parser_node));
+    break;
   case tokens::Type::CONSTRUCTOR:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          Run<nodes::Constructor>(parser_node), is_scoped));
+    expr = Run<nodes::Constructor>(parser_node);
+    break;
   case tokens::Type::LAMBDA:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), Run<nodes::Lambda>(parser_node), is_scoped));
+    expr = Run<nodes::Lambda>(parser_node);
+    break;
   // --- literals
   case tokens::Type::FLOAT_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_float_literal(parser_node), is_scoped));
+    expr = build_float_literal(parser_node);
+    break;
   case tokens::Type::DOUBLE_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_double_literal(parser_node), is_scoped));
+    expr = build_double_literal(parser_node);
+    break;
   case tokens::Type::INT_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_int_literal(parser_node), is_scoped));
+    expr = build_int_literal(parser_node);
+    break;
   case tokens::Type::LONG_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_long_literal(parser_node), is_scoped));
+    expr = build_long_literal(parser_node);
+    break;
   case tokens::Type::INDEX_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_index_literal(parser_node), is_scoped));
+    expr = build_index_literal(parser_node);
+    break;
   case tokens::Type::STRING_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_string_literal(parser_node), is_scoped));
+    expr = build_string_literal(parser_node);
+    break;
   case tokens::Type::UNICODE_STRING_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_unicode_string_literal(parser_node),
-        is_scoped));
+    expr = build_unicode_string_literal(parser_node);
+    break;
   case tokens::Type::CHAR_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_char_literal(parser_node), is_scoped));
+    expr = build_char_literal(parser_node);
+    break;
   case tokens::Type::UNICODE_LITERAL:
-    return state<Exprs>().add_expression(
-        nodes::Expression(build_node(parser_node),
-                          build_unicode_literal(parser_node), is_scoped));
+    expr = build_unicode_literal(parser_node);
+    break;
   case tokens::Type::BOOL_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_bool_literal(parser_node), is_scoped));
+    expr = build_bool_literal(parser_node);
+    break;
   case tokens::Type::UNIT_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_unit_literal(parser_node), is_scoped));
+    expr = build_unit_literal(parser_node);
+    break;
   case tokens::Type::NULL_LITERAL:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_null_literal(parser_node), is_scoped));
+    expr = build_null_literal(parser_node);
+    break;
   case tokens::Type::EXTRA:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_extra(parser_node), is_scoped));
+    expr = build_extra(parser_node);
+    break;
   case tokens::Type::EMPTY_LINES:
-    return state<Exprs>().add_expression(nodes::Expression(
-        build_node(parser_node), build_empty_lines(parser_node), is_scoped));
+    expr = build_empty_lines(parser_node);
+    break;
   default:
-    error_handling::handle_parsing_error("Unexprected expression node type",
-                                         parser_node);
+    utils::Assert(true,
+                  std::format("Unexpected expression node type {}",
+                              static_cast<int>(type))); // TODO: magic_enum
+    // FIXME: change to fatal error ?
   }
 
-  error_handling::handle_general_error("Unreachable");
-  exit(1); // unreachable
+  utils::Assert(expr.has_value(), "Expression should have value");
+
+  return state<Exprs>().add_expression(
+      {build_node(parser_node), expr.value(), is_scoped});
 }
 
 // --- flow control
 
 // (':=' | '=:') expression (('??' | 'if') expression)? (_do_ expression)?
-nodes::Match::Case BuilderTask<nodes::Match::Case>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Match::Case
+BuilderTask<nodes::Match::Case>::operator()(const ParserNode &parser_node,
+                                            const utils::None &) {
   std::string case_type = parser_node.nth_child(0).get_value();
 
-  std::optional<parser::ParseTree::Node> condition_node;
-  std::optional<parser::ParseTree::Node> expression_node;
+  std::optional<ParserNode> condition_node;
+  std::optional<ParserNode> expression_node;
 
   auto current_node = parser_node.nth_named_child(1);
 
@@ -192,8 +184,9 @@ nodes::Match::Case BuilderTask<nodes::Match::Case>::operator()(
 }
 
 // expression case+
-nodes::Match BuilderTask<nodes::Match>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Match
+BuilderTask<nodes::Match>::operator()(const ParserNode &parser_node,
+                                      const utils::None &) {
   std::vector<nodes::Match::Case> cases;
 
   auto current_node = parser_node.nth_named_child(1);
@@ -210,8 +203,9 @@ nodes::Match BuilderTask<nodes::Match>::operator()(
 
 // ('??' | 'if') expression _do_ expression (('!!' | 'elif') expression _do_
 // expression)* (('!!=>', 'else') expression)?
-nodes::Condition BuilderTask<nodes::Condition>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Condition
+BuilderTask<nodes::Condition>::operator()(const ParserNode &parser_node,
+                                          const utils::None &) {
   size_t named_child_count = parser_node.named_child_count();
 
   std::vector<std::pair<nodes::ExpressionProxy, nodes::ExpressionProxy>> cases;
@@ -238,32 +232,48 @@ nodes::Condition BuilderTask<nodes::Condition>::operator()(
 }
 
 // ('@' | 'for') (expression | expression ':' expression)? _do_ expression
-nodes::Loop
-BuilderTask<nodes::Loop>::operator()(const parser::ParseTree::Node &parser_node,
-                                     const utils::None &) {
+nodes::Loop BuilderTask<nodes::Loop>::operator()(const ParserNode &parser_node,
+                                                 const utils::None &) {
   size_t named_child_count = parser_node.named_child_count();
 
   if (named_child_count == 1) { // body
     return nodes::Loop(
         build_node(parser_node),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)));
-  } else if (named_child_count == 2) { // condition, body
+  } else if (named_child_count == 2) { // condition,
+                                       // body
     return nodes::Loop(
         build_node(parser_node),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(1)));
-  } else if (named_child_count == 3) { // variable, interval, body
+  } else if (named_child_count == 3) { // variable,
+                                       // interval,
+                                       // body
     return nodes::Loop(
         build_node(parser_node),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(1)),
         Run<nodes::ExpressionProxy>(parser_node.nth_named_child(2)));
   } else {
-    error_handling::handle_parsing_error(
-        "Unexprected named expression amount in loop", parser_node);
+    error_handling::handle_parsing_error("Unex"
+                                         "prec"
+                                         "ted "
+                                         "name"
+                                         "d "
+                                         "expr"
+                                         "essi"
+                                         "on "
+                                         "amou"
+                                         "nt "
+                                         "in "
+                                         "loo"
+                                         "p",
+                                         parser_node);
   }
 
-  error_handling::handle_general_error("Unreachable");
+  error_handling::handle_general_error("Unreac"
+                                       "habl"
+                                       "e");
   exit(1); // unreachable
 }
 
@@ -272,7 +282,7 @@ BuilderTask<nodes::Loop>::operator()(const parser::ParseTree::Node &parser_node,
 // expression ',' expression
 nodes::NameExpression
 BuilderTask<nodes::NameExpression, utils::CommaTag>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+    const ParserNode &parser_node, const utils::None &) {
   std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
       arguments;
 
@@ -293,8 +303,10 @@ BuilderTask<nodes::NameExpression, utils::CommaTag>::operator()(
 // expression operator expression
 nodes::NameExpression
 BuilderTask<nodes::NameExpression, utils::OperatorTag>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
-  auto name_node = parser_node.child_by_field_name("name");
+    const ParserNode &parser_node, const utils::None &) {
+  auto name_node = parser_node.child_by_field_name("na"
+                                                   "m"
+                                                   "e");
 
   std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
       arguments;
@@ -317,19 +329,25 @@ BuilderTask<nodes::NameExpression, utils::OperatorTag>::operator()(
 // --- modifiers
 
 // ('return' | 'bring') expression
-nodes::Return BuilderTask<nodes::Return>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Return
+BuilderTask<nodes::Return>::operator()(const ParserNode &parser_node,
+                                       const utils::None &) {
   std::string modifier = parser_node.nth_child(0).get_value();
 
   return nodes::Return(
       build_node(parser_node),
-      modifier == "return" ? nodes::Return::RETURN : nodes::Return::BRING,
+      modifier == "re"
+                  "tu"
+                  "rn"
+          ? nodes::Return::RETURN
+          : nodes::Return::BRING,
       Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)));
 }
 
 // _var_let_ (simple_name_identifier | placeholder)
-nodes::NameDefinition BuilderTask<nodes::NameDefinition>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::NameDefinition
+BuilderTask<nodes::NameDefinition>::operator()(const ParserNode &parser_node,
+                                               const utils::None &) {
   std::string modifier = parser_node.nth_child(0).get_value();
 
   auto name_node = parser_node.nth_named_child(0);
@@ -343,7 +361,7 @@ nodes::NameDefinition BuilderTask<nodes::NameDefinition>::operator()(
 
 // expression '[' expression ']'
 nodes::Access BuilderTask<nodes::Access, utils::ArrayAccessTag>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+    const ParserNode &parser_node, const utils::None &) {
   return nodes::Access(
       build_node(parser_node), nodes::Access::ARRAY,
       Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)),
@@ -352,20 +370,23 @@ nodes::Access BuilderTask<nodes::Access, utils::ArrayAccessTag>::operator()(
 
 // expression '.' number_literal
 nodes::Access BuilderTask<nodes::Access, utils::TupleAccessTag>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+    const ParserNode &parser_node, const utils::None &) {
   return nodes::Access(
       build_node(parser_node), nodes::Access::TUPLE,
       Run<nodes::ExpressionProxy>(parser_node.nth_named_child(0)),
-      state<Exprs>().add_expression(nodes::Expression(
-          build_node(parser_node.nth_named_child(1)),
-          build_index_literal(parser_node.nth_named_child(1)), false)));
+      state<Exprs>().add_expression(
+          {build_node(parser_node.nth_named_child(1)),
+           build_index_literal(parser_node.nth_named_child(1)), false}));
 }
 
 // 'break' | 'continue'
-nodes::LoopControl BuilderTask<nodes::LoopControl>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::LoopControl
+BuilderTask<nodes::LoopControl>::operator()(const ParserNode &parser_node,
+                                            const utils::None &) {
   return nodes::LoopControl(build_node(parser_node),
-                            parser_node.get_value() == "break"
+                            parser_node.get_value() == "br"
+                                                       "ea"
+                                                       "k"
                                 ? nodes::LoopControl::BREAK
                                 : nodes::LoopControl::CONTINUE);
 }
@@ -375,9 +396,8 @@ nodes::LoopControl BuilderTask<nodes::LoopControl>::operator()(
 // --- other
 
 void build_arguments_until_end(
-    parser::ParseTree::Node first_parse_node, Executor &executor,
+    ParserNode first_parse_node, Executor &executor,
     std::vector<nodes::AnnotatedArgument> &arguments) {
-
   auto current_node = first_parse_node;
 
   std::optional<std::string> last_annotation;
@@ -399,16 +419,18 @@ void build_arguments_until_end(
 // ')') (annotation? expression)*
 nodes::NameExpression
 BuilderTask<nodes::NameExpression, utils::FuncCallTag>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+    const ParserNode &parser_node, const utils::None &) {
   std::vector<nodes::AnnotatedArgument> arguments;
 
   std::optional<nodes::Type> prefix;
 
   bool is_point_call = false;
 
-  auto name_node = parser_node.child_by_field_name("name");
+  auto name_node = parser_node.child_by_field_name("na"
+                                                   "m"
+                                                   "e");
 
-  std::optional<parser::ParseTree::Node> prefix_node;
+  std::optional<ParserNode> prefix_node;
 
   auto current_node = name_node.previous_named_sibling();
   if (!current_node.is_null()) {
@@ -442,13 +464,17 @@ BuilderTask<nodes::NameExpression, utils::FuncCallTag>::operator()(
 }
 
 // type (annotation? expression)*
-nodes::Constructor BuilderTask<nodes::Constructor>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Constructor
+BuilderTask<nodes::Constructor>::operator()(const ParserNode &parser_node,
+                                            const utils::None &) {
   std::vector<nodes::AnnotatedArgument> arguments;
 
-  build_arguments_until_end(
-      parser_node.child_by_field_name("type").next_named_sibling(), executor,
-      arguments);
+  build_arguments_until_end(parser_node
+                                .child_by_field_name("ty"
+                                                     "p"
+                                                     "e")
+                                .next_named_sibling(),
+                            executor, arguments);
 
   return nodes::Constructor(
       build_node(parser_node),
@@ -457,8 +483,9 @@ nodes::Constructor BuilderTask<nodes::Constructor>::operator()(
 }
 
 // '\\' argument_name* _do_ expression
-nodes::Lambda BuilderTask<nodes::Lambda>::operator()(
-    const parser::ParseTree::Node &parser_node, const utils::None &) {
+nodes::Lambda
+BuilderTask<nodes::Lambda>::operator()(const ParserNode &parser_node,
+                                       const utils::None &) {
   std::vector<nodes::Identifier> arguments;
 
   auto current_node =
diff --git a/lang/nodes/include/expression_nodes.hpp b/lang/nodes/include/expression_nodes.hpp
index 8ffded9..47a624e 100644
--- a/lang/nodes/include/expression_nodes.hpp
+++ b/lang/nodes/include/expression_nodes.hpp
@@ -529,33 +529,7 @@ private:
 
 class Expression : public Node {
 public:
-  template <typename T>
-  Expression(Node node, T &&expression, bool is_scoped)
-      : Node(node), expression_(std::forward<T>(expression)),
-        is_scoped_(is_scoped) {}
-
-  template <typename T> std::optional<T *> get() {
-    if (std::holds_alternative<T>(expression_)) {
-      return &std::get<T>(expression_);
-    }
-    return std::nullopt;
-  }
-
-  template <typename T> std::optional<const T *> get() const {
-    if (std::holds_alternative<T>(expression_)) {
-      return &std::get<T>(expression_);
-    }
-    return std::nullopt;
-  }
-
-  auto get_any() { return &expression_; }
-
-  auto get_any() const { return &expression_; }
-
-  bool is_scoped() const { return is_scoped_; }
-
-private:
-  std::variant<
+  using Type = std::variant<
       // --- flow control
       Match, Condition, Loop,
 
@@ -585,8 +559,36 @@ private:
       Extra,
 
       // --- empty lines
-      EmptyLines>
-      expression_;
+      EmptyLines>;
+
+public:
+  template <typename T>
+  Expression(Node node, T &&expression, bool is_scoped)
+      : Node(node), expression_(std::forward<T>(expression)),
+        is_scoped_(is_scoped) {}
+
+  template <typename T> std::optional<T *> get() {
+    if (std::holds_alternative<T>(expression_)) {
+      return &std::get<T>(expression_);
+    }
+    return std::nullopt;
+  }
+
+  template <typename T> std::optional<const T *> get() const {
+    if (std::holds_alternative<T>(expression_)) {
+      return &std::get<T>(expression_);
+    }
+    return std::nullopt;
+  }
+
+  auto get_any() { return &expression_; }
+
+  auto get_any() const { return &expression_; }
+
+  bool is_scoped() const { return is_scoped_; }
+
+private:
+  Type expression_;
 
   bool is_scoped_ = false;
 };