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

bindings/python/src/expression.rs

@@ -33,3 +33,13 @@ pub fn evaluate_unary_expression(expression: String, ctx: &PyDict) -> PyResult<b
 
     Ok(result)
 }
+
+#[pyfunction]
+pub fn render_template(py: Python, template: String, ctx: &PyDict) -> PyResult<PyObject> {
+    let context: Value = depythonize(ctx).context("Failed to convert context")?;
+
+    let result = zen_template::render(template.as_str(), &context)
+        .map_err(|e| anyhow!(serde_json::to_string(&e).unwrap_or_else(|_| e.to_string())))?;
+
+    Ok(PyValue(result).to_object(py))
+}