move Expr out of parser

src/eval.rs

@@ -1,4 +1,4 @@
-use crate::parser::{BinaryOp, Expr, UnaryOp};
+use crate::expr::{BinaryOp, Expr, UnaryOp};
 
 pub struct Evaluator {
     ast: Expr

src/expr.rs

@@ -0,0 +1,45 @@
+#[derive(Debug, Clone)]
+pub enum BinaryOp {
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod
+}
+
+#[derive(Debug, Clone)]
+pub enum UnaryOp {
+    Neg
+}
+
+pub fn prefix_bp(op: &UnaryOp) -> u8 {
+    match op {
+        UnaryOp::Neg => 5
+    }
+}
+
+pub fn infix_bp(op: &BinaryOp) -> (u8, u8) {
+    match op {
+        BinaryOp::Add | BinaryOp::Sub => (1, 2),
+        BinaryOp::Mul | BinaryOp::Div | BinaryOp::Mod => (3, 4)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum Expr {
+    Number(i64),
+    Ident(String),
+    EOL,
+
+    Binary {
+        op: BinaryOp,
+        left: Box<Expr>,
+        right: Box<Expr>
+    },
+
+    Unary {
+        op: UnaryOp,
+        right: Box<Expr>
+    }
+}
+

src/main.rs

@@ -1,6 +1,7 @@
 use std::{fs::File, io::Read};
 
 mod token;
+mod expr;
 mod lexer;
 use lexer::Lexer;
 mod parser;
@@ -30,7 +31,7 @@ fn main() -> std::io::Result<()> {
     loop {
         let parsed = parser.parse();
         match parsed {
-            parser::Expr::EOL => break,
+            expr::Expr::EOL => break,
             _ => {
                 println!("AST:   {:?}", parsed);
                 let eval = Evaluator::new(parsed);

src/parser.rs

@@ -1,49 +1,5 @@
 use crate::token::Token;
-
-#[derive(Debug, Clone)]
-pub enum BinaryOp {
-    Add,
-    Sub,
-    Mul,
-    Div,
-    Mod
-}
-
-#[derive(Debug, Clone)]
-pub enum UnaryOp {
-    Neg
-}
-
-fn prefix_bp(op: &UnaryOp) -> u8 {
-    match op {
-        UnaryOp::Neg => 5
-    }
-}
-
-fn infix_bp(op: &BinaryOp) -> (u8, u8) {
-    match op {
-        BinaryOp::Add | BinaryOp::Sub => (1, 2),
-        BinaryOp::Mul | BinaryOp::Div | BinaryOp::Mod => (3, 4)
-    }
-}
-
-#[derive(Debug, Clone)]
-pub enum Expr {
-    Number(i64),
-    Ident(String),
-    EOL,
-
-    Binary {
-        op: BinaryOp,
-        left: Box<Expr>,
-        right: Box<Expr>
-    },
-
-    Unary {
-        op: UnaryOp,
-        right: Box<Expr>
-    }
-}
+use crate::expr::{Expr, UnaryOp, BinaryOp, infix_bp, prefix_bp};
 
 pub struct Parser {
     tokens: Vec<Token>,