initial commit wip2

examples/stacked_borrows.rs

@@ -57,18 +57,43 @@ enum Stmt {
     Assign(Expr, Expr),
 }
 
-fn left_expr(e: &Expr) -> &Id {
+fn left_expr(e: &Expr) -> Id {
     match e {
-        Expr::Id(id) => id,
+        Expr::Id(id) => id.to_owned(),
         Expr::Deref(e) => left_expr(e),
         _ => unimplemented!("illegal left hand"),
     }
 }
 
+fn right_expr(e: &Expr) -> &Expr {
+    println!("right_expr {:?}", e);
+    match e {
+        Expr::Id(_) => e,
+        Expr::Lit => e,
+        Expr::Ref(_) => {
+            println!("Ref");
+            e
+        }
+        Expr::RefMut(_) => {
+            println!("RefMut");
+            e
+        }
+        Expr::Deref(e) => {
+            println!("Deref");
+            right_expr(e)
+        }
+    }
+}
+
 fn check_stmt(s: &Stmt, store: &mut Store) {
     match s {
         Stmt::Let(id, e) => store.alloc(id.to_owned()),
-        Stmt::Assign(le, re) => {}
+        Stmt::Assign(le, re) => {
+            println!("assign le :{:?}, re: {:?}", le, re);
+            let id = left_expr(le);
+            let e = right_expr(re);
+            println!("assign id :{:?}, re: {:?}", id, e);
+        }
     }
 }
 
@@ -87,6 +112,7 @@ fn main() {
         Let(id("b"), Lit),                         // let b = ...;
         Let(id("c"), Ref(Box::new(Id(id("a"))))),  // let c = &a;
         Assign(Id(id("a")), Lit),                  // a = ...;
+        Assign(Deref(Box::new(Id(id("c")))), Lit), // *c = ..;
     ];
 
     println!("prog {:?}", v);