Need to do loop elements.

src/renderer/parameters_context.rs

@@ -4,6 +4,7 @@ use crate::renderer::context_element::ContextElement;
 use crate::renderer::Loopable;
 use crate::renderer::RenderError;
 use crate::renderer::Renderable;
+use crate::renderer::WalkError;
 use crate::renderer::Walkable;
 use std::collections::HashMap;
 
@@ -44,11 +45,8 @@ impl<'a> Loopable for ParametersContext<'a> {
 }
 
 impl<'a> Walkable for ParametersContext<'a> {
-    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError> {
+    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
         // TODO: Actually implement
-        Err(RenderError::CantWalk {
-            segment: segment.to_string(),
-            elem: self,
-        })
+        Err(WalkError::CantWalk)
     }
 }