logos calculator example

src/main.rs

@@ -0,0 +1,36 @@
+use chumsky::Parser;
+use logos::Logos;
+
+use crate::{parser::parser, tokens::Token};
+
+mod tokens;
+mod ast;
+mod parser;
+
+fn main() {
+    let lexer = Token::lexer("(1 + 1) * 3");
+
+    let mut tokens = vec![];
+    for (token, span) in lexer.spanned() {
+        match token {
+            Ok(token) => tokens.push(token),
+            Err(e) => {
+                println!("lexer error at {:?}: {:?}", span, e);
+                return;
+            }
+        }
+    }
+
+    let ast = match parser().parse(&tokens).into_result() {
+        Ok(expr) => {
+            println!("[AST]\n{:#?}", expr);
+            expr
+        }
+        Err(e) => {
+            println!("parse error: {:#?}", e);
+            return;
+        }
+    };
+
+    println!("\n[result]\n{}", ast.eval());
+}