Use custom Arc backed input

Signed-off-by: Marcel Müller <neikos@neikos.email>

src/eval/mod.rs

@@ -5,11 +5,12 @@ use thiserror::Error;
 
 use crate::Context;
 use crate::emit::Instruction;
+use crate::input::TempleInput;
 
 #[derive(Debug, Error, Display)]
 enum EvalError {
     /// An unknown variable was encountered: .0
-    UnknownVariable(String),
+    UnknownVariable(TempleInput),
     /// An explicit abort was requested
     ExplicitAbort,
 }
@@ -25,7 +26,7 @@ fn execute(instructions: &[Instruction], global_context: &Context) -> Result<Str
             Instruction::LoadFromContextToSlot { name, slot } => {
                 let value = global_context
                     .values
-                    .get(name)
+                    .get(name.as_str())
                     .ok_or(EvalError::UnknownVariable(name.clone()))?;
 
                 scopes.insert(*slot, value.clone());