feat: custom node (#138)

* feat: custom node

* add zen template, expose $nodes and $root

* add custom handler to go and nodejs

* add support for python, improve bindings, add error to zen template

* fix: correct binding exports for nodejs and python

* fix benchmark

* improve rust api, trim template in zen templates

* update cargo action

* update expression version

* compile action

* fix action format

core/expression/src/parser/ast.rs

@@ -13,6 +13,7 @@ pub enum Node<'a> {
     Array(&'a [&'a Node<'a>]),
     Identifier(&'a str),
     Closure(&'a Node<'a>),
+    Root,
     Member {
         node: &'a Node<'a>,
         property: &'a Node<'a>,

core/expression/src/parser/parser.rs

@@ -280,7 +280,11 @@ impl<'arena, 'token_ref, Flavor> Parser<'arena, 'token_ref, Flavor> {
         self.next()?;
         let current_token = self.current();
         if current_token.kind != TokenKind::Bracket(Bracket::LeftParenthesis) {
-            let identifier_node = self.node(Node::Identifier(identifier_token.value));
+            let identifier_node = match identifier_token.kind {
+                TokenKind::Identifier(Identifier::RootReference) => self.node(Node::Root),
+                _ => self.node(Node::Identifier(identifier_token.value)),
+            };
+
             return self
                 .with_postfix(identifier_node, expression_parser)
                 .map(Some);

core/expression/src/parser/unary.rs

@@ -214,6 +214,7 @@ impl From<&Node<'_>> for UnaryNodeBehaviour {
 
         match value {
             Node::Null => CompareWithReference(Equal),
+            Node::Root => CompareWithReference(Equal),
             Node::Bool(_) => CompareWithReference(Equal),
             Node::Number(_) => CompareWithReference(Equal),
             Node::String(_) => CompareWithReference(Equal),