diff --git a/ablescript/src/ast.rs b/ablescript/src/ast.rs
index 3a7941e..447fd45 100644
--- a/ablescript/src/ast.rs
+++ b/ablescript/src/ast.rs
@@ -50,19 +50,21 @@ pub enum AssignableKind {
     Index { indices: Vec<Expr> },
 }
 
+pub struct InvalidAssignable;
+
 impl Assignable {
-    pub fn from_expr(expr: Expr) -> Result<Assignable, ()> {
+    pub fn from_expr(expr: Expr) -> Result<Assignable, InvalidAssignable> {
         match expr.kind {
             ExprKind::Variable(ident) => Ok(Assignable {
                 ident: Ident::new(ident, expr.span),
                 kind: AssignableKind::Variable,
             }),
             ExprKind::Index { expr, index } => Self::from_index(*expr, *index),
-            _ => Err(()),
+            _ => Err(InvalidAssignable),
         }
     }
 
-    fn from_index(mut buf: Expr, index: Expr) -> Result<Assignable, ()> {
+    fn from_index(mut buf: Expr, index: Expr) -> Result<Assignable, InvalidAssignable> {
         let mut indices = vec![index];
         let ident = loop {
             match buf.kind {
@@ -71,7 +73,7 @@ impl Assignable {
                     indices.push(*index);
                     buf = *expr;
                 }
-                _ => return Err(()),
+                _ => return Err(InvalidAssignable),
             }
         };
 
diff --git a/ablescript/src/interpret.rs b/ablescript/src/interpret.rs
index 0d0b149..2a38632 100644
--- a/ablescript/src/interpret.rs
+++ b/ablescript/src/interpret.rs
@@ -50,6 +50,15 @@ struct Scope {
     variables: HashMap<String, Variable>,
 }
 
+impl Default for ExecEnv {
+    fn default() -> Self {
+        Self {
+            stack: vec![Default::default()],
+            read_buf: Default::default(),
+        }
+    }
+}
+
 impl Default for Scope {
     fn default() -> Self {
         Self {
@@ -80,11 +89,7 @@ impl ExecEnv {
     /// Create a new Scope with no predefined variable definitions or
     /// other information.
     pub fn new() -> Self {
-        Self {
-            // We always need at least one stackframe.
-            stack: vec![Default::default()],
-            read_buf: Default::default(),
-        }
+        Self::default()
     }
 
     /// Create a new Scope with predefined variables
@@ -190,7 +195,7 @@ impl ExecEnv {
                     .map(|x| x.borrow().clone())
                     .unwrap_or(Value::Nul)
             }
-            Len(expr) => Value::Int(self.eval_expr(expr)?.len()),
+            Len(expr) => Value::Int(self.eval_expr(expr)?.length()),
 
             // TODO: not too happy with constructing an artificial
             // Ident here.
@@ -476,7 +481,7 @@ impl ExecEnv {
                 .chain(
                     args[2 * n_alternations..]
                         .iter()
-                        .map(|r| Rc::clone(r))
+                        .map(Rc::clone)
                         .take(extra_l),
                 )
                 .collect(),
@@ -486,7 +491,7 @@ impl ExecEnv {
                 .chain(
                     args[2 * n_alternations..]
                         .iter()
-                        .map(|r| Rc::clone(r))
+                        .map(Rc::clone)
                         .take(extra_r),
                 )
                 .collect(),
diff --git a/ablescript/src/lexer.rs b/ablescript/src/lexer.rs
index 1ae88ab..95cc355 100644
--- a/ablescript/src/lexer.rs
+++ b/ablescript/src/lexer.rs
@@ -1,7 +1,5 @@
 use logos::{Lexer, Logos};
 
-use crate::variables::Abool;
-
 #[derive(Logos, Debug, PartialEq, Clone)]
 pub enum Token {
     // Symbols
@@ -121,8 +119,8 @@ pub enum Token {
     #[regex(r"-?[0-9]+", get_value)]
     Integer(isize),
 
-    /// A C-complaint identifier
-    #[regex(r"[a-zA-Z_][a-zA-Z_0-9]*", get_ident)]
+    /// An identifier
+    #[regex(r"\p{XID_Start}\p{XID_Continue}*", get_ident)]
     Identifier(String),
 
     #[regex(r"owo .*")]
diff --git a/ablescript/src/variables.rs b/ablescript/src/variables.rs
index 552c067..992b88d 100644
--- a/ablescript/src/variables.rs
+++ b/ablescript/src/variables.rs
@@ -104,7 +104,7 @@ impl std::fmt::Debug for BuiltinFunctio {
 
 impl PartialEq for BuiltinFunctio {
     fn eq(&self, other: &Self) -> bool {
-        Rc::ptr_eq(&self.function, &other.function) && self.arity == other.arity
+        self.fn_addr() == other.fn_addr() && self.arity == other.arity
     }
 }
 
@@ -264,7 +264,7 @@ impl Value {
                 .into_abool(),
                 Functio::Able { params, body } => {
                     let str_to_isize = |x: String| -> isize {
-                        x.as_bytes().into_iter().map(|x| *x as isize).sum()
+                        x.as_bytes().iter().map(|x| *x as isize).sum()
                     };
 
                     let params: isize = params.into_iter().map(str_to_isize).sum();
@@ -482,8 +482,8 @@ impl Value {
         }
     }
 
-    /// Get a lenght of a value
-    pub fn len(&self) -> isize {
+    /// Get a length of a value
+    pub fn length(&self) -> isize {
         match self {
             Value::Nul => 0,
             Value::Str(s) => s.len() as _,
@@ -547,7 +547,7 @@ impl ops::Add for Value {
                 Value::Functio(_) => Value::Functio(self.into_functio()) + rhs,
                 Value::Cart(_) => Value::Cart(self.into_cart()) + rhs,
             },
-            Value::Str(s) => Value::Str(format!("{}{}", s, rhs.to_string())),
+            Value::Str(s) => Value::Str(format!("{s}{rhs}")),
             Value::Int(i) => Value::Int(i.wrapping_add(rhs.into_isize())),
             Value::Bool(b) => Value::Bool(b || rhs.into_bool()),
             Value::Abool(_) => {
diff --git a/ablescript_cli/src/repl.rs b/ablescript_cli/src/repl.rs
index 5959302..eca64b9 100644
--- a/ablescript_cli/src/repl.rs
+++ b/ablescript_cli/src/repl.rs
@@ -18,7 +18,7 @@ pub fn repl(ast_print: bool) {
                 rl.add_history_entry(readline);
                 
                 let partial_data = match partial {
-                    Some(line) => line + &readline,
+                    Some(line) => line + readline,
                     None => readline.to_owned(),
                 };