Improved Scanner

src/main.rs

@@ -4,8 +4,10 @@ use clap::{App, Arg};
 mod base_55;
 mod parser;
 pub mod tokens;
+mod scanner;
 
 use logos::Logos;
+use scanner::Scanner;
 
 fn main() {
     let matches = App::new("AbleScript")
@@ -27,10 +29,8 @@ fn main() {
             let source = std::fs::read_to_string(file_path).unwrap();
 
             // Print token type: `value`
-            let mut lex = tokens::Token::lexer(&source);
+            let mut scanner = Scanner::new(&source);
-            while let Some(token) = lex.next() {
+            scanner.scan();
-                println!("{:?}: `{}`", token, lex.slice());
-            }
         }
         None => {
             println!("hi");

src/scanner.rs

@@ -0,0 +1,33 @@
+use std::ops::Range;
+
+use logos::Logos;
+
+use crate::tokens::{self, Token};
+pub struct Scanner<'a> {
+    source: &'a str,
+    lexer: logos::Lexer<'a, Token>,
+}
+
+impl<'a> Scanner<'a> {
+    pub fn new(source: &'a str) -> Self {
+        Self {
+            source,
+            lexer: tokens::Token::lexer(source),
+        }
+    }
+
+    pub fn scan(&mut self) {
+        while let Some(tok) = self.lexer.next() {
+            if matches!(tok, Token::Error) {
+                self.throw_err(&self.lexer.span());
+            } else {
+                println!("Token: {:?}", tok);
+            }
+        }
+    }
+
+    fn throw_err(&self, location: &Range<usize>) {
+        let part = &self.source[location.clone()];
+        println!("Unknown keyword `{}` found on {:?}", part, location);
+    }
+}