Mise en place formelle du visiteur et séparation de l'affichage d'un arbre syntaxique abstrait (AST).

src/main.rs

@@ -1,17 +1,20 @@
 use std::env;
 use std::process;
-use crate::expr::{Binary, Expr, Grouping, Literal, Unary, Visitable};
-use crate::expr::Expr::LiteralExpr;
 
 mod rlox_interpreter;
+
 mod scanner;
 mod token;
 mod token_type;
 mod expr;
+mod astprinter;
 
 use crate::rlox_interpreter::RLoxInterpreter;
 use crate::token::Token;
 use crate::token_type::TokenType;
+use crate::expr::{Binary, Expr, Grouping, Literal, Unary, VisitableExpr};
+use crate::expr::Expr::LiteralExpr;
+use crate::astprinter::ASTPrinter;
 
 // Exit codes from #include <sysexits.h>
 const EX_OK: i32 = 0;
@@ -44,7 +47,7 @@ fn essai_visitor() {
                 line: 0,
                 literal: String::from("-")
             },
-            right: Box::new(Expr::LiteralExpr(Literal::LiteralNumber(123.0)))
+            right: Box::new(Expr::LiteralExpr(Literal::LiteralNumber(456.0)))
         })),
         operator: Token {
             token_type: TokenType::Star,
@@ -57,7 +60,8 @@ fn essai_visitor() {
         }))
     });
 
-    expression.visit();
+    let a = ASTPrinter{};
+    expression.accept(&a);
 }