Ajout des instructions.

src/astprinter.rs

@@ -1,4 +1,5 @@
 use crate::expr::{Binary, Expr, ExprVisitor, Grouping, Literal, Unary};
+use crate::stmt::{ExpressionStatement, PrintStatement, StatementVisitor};
 
 pub struct ASTPrinter {
     pub(crate) depth: u32
@@ -59,4 +60,22 @@ impl ExprVisitor<()> for ASTPrinter {
             Expr::UnaryExpr(u) => { self.visit_unary(u); }
         }
     }
+}
+
+impl StatementVisitor<()> for ASTPrinter {
+    fn visit_expr_stmt(&mut self, e: &ExpressionStatement) -> () {
+        println!("{} EXPR_STMT(", self.ast_tab());
+        self.depth+=1;
+        self.visit_expr(&e.expr);
+        self.depth-=1;
+        print!(") ");
+    }
+
+    fn visit_print(&mut self, p: &PrintStatement) -> () {
+        println!("{} EXPR_STMT(", self.ast_tab());
+        self.depth+=1;
+        self.visit_expr(&p.expr);
+        self.depth-=1;
+        print!(") ");
+    }
 }

src/expr.rs

@@ -1,11 +1,13 @@
 use crate::token::Token;
 
+#[derive(Clone)]
 pub struct Binary {
     pub left: Box<Expr>,
     pub operator: Token,
     pub right: Box<Expr>,
 }
 
+#[derive(Clone)]
 pub struct Grouping {
     pub expression: Box<Expr>,
 }
@@ -18,11 +20,13 @@ pub enum Literal {
     LiteralNil,
 }
 
+#[derive(Clone)]
 pub struct Unary {
     pub operator: Token,
     pub right: Box<Expr>,
 }
 
+#[derive(Clone)]
 pub enum Expr {
     BinaryExpr(Binary),
     GroupingExpr(Grouping),

src/interpreter.rs

@@ -7,10 +7,12 @@ use crate::expr::Literal::LiteralNumber;
 use crate::expr::Literal::LiteralBool;
 use crate::expr::Literal::LiteralNil;
 use crate::expr::{Binary, Expr, ExprVisitor, Grouping, Literal, Unary};
+use crate::stmt::{ExpressionStatement, PrintStatement, StatementVisitor};
 use crate::token_type::TokenType;
 
 pub struct Interpreter;
 
+#[derive(Debug)]
 pub struct RuntimeError {
     pub(crate) message: String
 }
@@ -145,4 +147,24 @@ impl ExprVisitor<Result<Literal, RuntimeError>> for Interpreter {
             UnaryExpr(u) => { Ok(self.visit_unary(&u)?) }
         }
     }
-}
+}
+
+impl StatementVisitor<()> for Interpreter {
+    fn visit_expr_stmt(&mut self, e: &ExpressionStatement) -> () {
+        self.visit_expr(&e.expr).expect("Erreur pendant l'évaluation de l'expression.");
+    }
+
+    fn visit_print(&mut self, p: &PrintStatement) -> () {
+        match self.visit_expr(&p.expr) {
+            Ok(lit) => match (lit) {
+                Literal::LiteralNumber(f) => { println!("{}", f); }
+                Literal::LiteralString(s) => { println!("{}", s); }
+                Literal::LiteralBool(b) => { println!("{}", b); }
+                Literal::LiteralNil => { println!("nul")}
+            }
+            Err(e) => panic!("{}", e.message)
+        }
+    }
+}
+
+

src/main.rs

@@ -2,7 +2,7 @@ use std::{env, fs, io};
 use std::io::Write;
 use std::process;
 use crate::astprinter::ASTPrinter;
-use crate::expr::{ExprVisitor, Literal};
+use crate::expr::ExprVisitor;
 use crate::interpreter::Interpreter;
 use crate::parser::Parser;
 
@@ -13,8 +13,10 @@ mod token_type;
 mod expr;
 mod astprinter;
 mod parser;
+mod stmt;
 
 use crate::scanner::Scanner;
+use crate::stmt::{Statement, StatementVisitor};
 
 // Exit codes from #include <sysexits.h>
 const EX_OK: i32 = 0;
@@ -71,26 +73,24 @@ fn run(src: String) -> i32 {
 
     println!("Parser");
     let mut parser = Parser::new( scanner.tokens );
-    match parser.parse() {
-        Some(expr) => {
-            println!("AST");
-            let mut printer = ASTPrinter { depth: 0 };
-            printer.visit_expr(&expr);
-            println!("Interpretation");
-            let mut interpreter = Interpreter;
-            let result = interpreter.visit_expr(&expr);
-            match result {
-                Ok(r) => { match r {
-                    Literal::LiteralNumber(f) => { println!("Resultat numérique = {}", f); }
-                    Literal::LiteralString(s) => { println!("Résultat chaîne = {}", s); }
-                    Literal::LiteralBool(b) => { println!("Résultat booléen = {}", b); }
-                    Literal::LiteralNil => { println!("Résultat nul")}
-                }}
-                Err(e) => { println!("Erreur d'exécution : {}", e.message); return EX_EXECERR; }
-            }
-            println!();
-        },
-        None => { println!("An error occurred while parsing expression."); return EX_DATAERR; }
+    let program = parser.parse();
+
+    println!("AST");
+    let mut printer = ASTPrinter { depth: 0 };
+    for s in program.clone() {
+        match s {
+            Statement::Expression(e) => { printer.visit_expr_stmt(&e) }
+            Statement::Print(p) => { printer.visit_print(&p) }
+        }
+    }
+
+    println!("Interpretation");
+    let mut interpreter = Interpreter;
+    for s in program {
+        match s {
+            Statement::Expression(e) => { interpreter.visit_expr_stmt(&e) }
+            Statement::Print(p) => { interpreter.visit_print(&p) }
+        }
     }
 
     EX_OK
@@ -101,4 +101,4 @@ fn run(src: String) -> i32 {
 // https://github.com/munificent/craftinginterpreters/wiki/Lox-implementations#rust
 
 // Pause :
-// http://www.craftinginterpreters.com/statements-and-state.html
+// http://www.craftinginterpreters.com/statements-and-state.html#global-variables

src/parser.rs

@@ -2,12 +2,14 @@ use crate::expr::{Binary, Expr, Grouping, Unary};
 use crate::expr::Literal::{LiteralBool, LiteralNumber, LiteralString};
 use crate::token::Token;
 use crate::token_type::TokenType;
+use crate::stmt::{ExpressionStatement, PrintStatement, Statement};
 
 pub struct Parser {
     tokens: Vec<Token>,
     current: usize
 }
 
+#[derive(Debug)]
 pub struct ParseError {
     message: String
 }
@@ -203,13 +205,32 @@ impl Parser {
         }
     }
 
-    pub fn parse(&mut self) -> Option<Expr> {
-        match self.expression() {
-            Ok(expr) => Some(expr),
-            Err(error) => {
-                println!("Error while parsing expression : {}",error.message);
-                None
-            }
+    fn statement(&mut self) -> Statement {
+        if self.match_token(&[TokenType::Print]) {
+            self.print_statement()
+        } else {
+            self.expr_statement()
         }
     }
+
+    fn print_statement(&mut self) -> Statement {
+        let e = self.expression().unwrap();
+        self.consume(&TokenType::Semicolon, String::from("; attendu")).unwrap();
+        Statement::Print(PrintStatement{ expr: e })
+    }
+
+    fn expr_statement(&mut self) -> Statement {
+        let e = self.expression().unwrap();
+        self.consume(&TokenType::Semicolon, String::from("; attendu")).unwrap();
+        Statement::Expression(ExpressionStatement{ expr: e })
+    }
+
+    pub fn parse(&mut self) -> Vec<Statement> {
+        let mut statements= Vec::new();
+        while !self.is_at_end() {
+            statements.push(self.statement());
+        }
+
+        statements
+    }
 }

src/stmt.rs

@@ -0,0 +1,22 @@
+use crate::expr::Expr;
+
+#[derive(Clone)]
+pub enum Statement {
+    Expression(ExpressionStatement),
+    Print(PrintStatement)
+}
+
+#[derive(Clone)]
+pub struct ExpressionStatement {
+    pub expr: Expr
+}
+
+#[derive(Clone)]
+pub struct PrintStatement {
+    pub expr: Expr
+}
+
+pub trait StatementVisitor<T> {
+    fn visit_expr_stmt(&mut self, e: &ExpressionStatement) -> T;
+    fn visit_print(&mut self, p: &PrintStatement) -> T;
+}