Pick this up again, dust it off, get some stuff connected.

src/syntax/tokens.rs

@@ -1,18 +1,17 @@
 use crate::util::istring::InternedString;
 use logos::{Lexer, Logos};
+use std::fmt;
 use std::num::ParseIntError;
 
 #[derive(Logos, Clone, Debug, PartialEq)]
 pub enum Token {
-    #[regex(r"[ \t\n\f]+", logos::skip)]
-    #[regex(r"//.*", logos::skip)]
     #[token("=")]
     Equals,
 
     #[token(";")]
     Semi,
 
-    #[regex(r"[+\-*/]", |v| v.slice().chars().nth(0))]
+    #[regex(r"[+\-*/]", |v| v.slice().chars().next())]
     Operator(char),
 
     #[regex(r"0b[01]+", |v| parse_number(Some(2), v))]
@@ -26,9 +25,29 @@ pub enum Token {
     Variable(InternedString),
 
     #[error]
+    #[regex(r"[ \t\r\n\f]+", logos::skip)]
+    #[regex(r"//.*", logos::skip)]
     Error,
 }
 
+impl fmt::Display for Token {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Token::Equals => write!(f, "'='"),
+            Token::Semi => write!(f, "';'"),
+            Token::Operator(c) => write!(f, "'{}'", c),
+            Token::Number((None, v)) => write!(f, "'{}'", v),
+            Token::Number((Some(2), v)) => write!(f, "'0b{:b}'", v),
+            Token::Number((Some(8), v)) => write!(f, "'0o{:o}'", v),
+            Token::Number((Some(10), v)) => write!(f, "'{}'", v),
+            Token::Number((Some(16), v)) => write!(f, "'0x{:x}'", v),
+            Token::Number((Some(b), v)) => write!(f, "Invalidly-based-number<base={},val={}>", b, v),
+            Token::Variable(s) => write!(f, "'{}'", s),
+            Token::Error => write!(f, "<error>"),
+        }
+    }
+}
+
 #[cfg(test)]
 impl Token {
     pub(crate) fn var(s: &str) -> Token {
@@ -36,9 +55,9 @@ impl Token {
     }
 }
 
-fn parse_number<'a, 'src>(
+fn parse_number(
     base: Option<u8>,
-    value: &'a Lexer<'src, Token>,
+    value: &Lexer<Token>,
 ) -> Result<(Option<u8>, i128), ParseIntError> {
     let (radix, strval) = match base {
         None => (10, value.slice()),