Replaced the String in Token with &'a str

.gitignore

@@ -1 +1,2 @@
 /target
+.DS_Store

numbat-cli/src/main.rs

@@ -465,14 +465,11 @@ impl Cli {
             }),
         };
 
-        let (result, registry) = {
-            let mut ctx = self.context.lock().unwrap();
-            let registry = ctx.dimension_registry().clone(); // TODO: get rid of this clone
-            (
-                ctx.interpret_with_settings(&mut settings, input, code_source),
-                registry,
-            )
-        };
+        let result =
+            self.context
+                .lock()
+                .unwrap()
+                .interpret_with_settings(&mut settings, input, code_source);
 
         let interactive = execution_mode == ExecutionMode::Interactive;
 
@@ -504,9 +501,11 @@ impl Cli {
                     println!();
                 }
 
+                let ctx = self.context.lock().unwrap();
+                let registry = ctx.dimension_registry();
                 let result_markup = interpreter_result.to_markup(
                     statements.last(),
-                    &registry,
+                    registry,
                     interactive || pretty_print,
                     interactive || pretty_print,
                 );

numbat/src/ffi/functions.rs

@@ -24,7 +24,7 @@ pub(crate) fn functions() -> &'static HashMap<String, ForeignFunction> {
                 m.insert(
                     $fn_name.to_string(),
                     ForeignFunction {
-                        name: $fn_name.to_string(),
+                        name: $fn_name,
                         arity: $arity,
                         callable: Callable::Function(Box::new($callable)),
                     },

numbat/src/ffi/mod.rs

@@ -31,7 +31,7 @@ pub(crate) enum Callable {
 }
 
 pub(crate) struct ForeignFunction {
-    pub(crate) name: String,
+    pub(crate) name: &'static str,
     pub(crate) arity: ArityRange,
     pub(crate) callable: Callable,
 }

numbat/src/ffi/procedures.rs

@@ -19,23 +19,23 @@ pub(crate) fn procedures() -> &'static HashMap<ProcedureKind, ForeignFunction> {
         m.insert(
             ProcedureKind::Print,
             ForeignFunction {
-                name: "print".into(),
+                name: "print",
                 arity: 0..=1,
                 callable: Callable::Procedure(print),
             },
         );
         m.insert(
             ProcedureKind::Assert,
             ForeignFunction {
-                name: "assert".into(),
+                name: "assert",
                 arity: 1..=1,
                 callable: Callable::Procedure(assert),
             },
         );
         m.insert(
             ProcedureKind::AssertEq,
             ForeignFunction {
-                name: "assert_eq".into(),
+                name: "assert_eq",
                 arity: 2..=3,
                 callable: Callable::Procedure(assert_eq),
             },