From dc2db1d0e8e5e68b9eb9029b30c5fb19857564f5 Mon Sep 17 00:00:00 2001
From: Mark <>
Date: Thu, 22 Feb 2024 19:41:03 +0100
Subject: [PATCH] make list.get_mut return a 1-tuple on success, and fix
 reference type being incomplete

---
 mers_lib/src/data/reference.rs            |  4 +--
 mers_lib/src/program/configs/with_list.rs | 36 +++++++++++++----------
 mers_lib/src/program/run/variable.rs      | 15 ++++++----
 3 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/mers_lib/src/data/reference.rs b/mers_lib/src/data/reference.rs
index 26b7518..21d7a1c 100755
--- a/mers_lib/src/data/reference.rs
+++ b/mers_lib/src/data/reference.rs
@@ -7,7 +7,7 @@ use std::{
 use super::{Data, MersData, MersType, Type};
 
 #[derive(Debug, Clone)]
-pub struct Reference(pub Arc<RwLock<Data>>);
+pub struct Reference(pub Arc<RwLock<Data>>, pub Type);
 
 impl MersData for Reference {
     fn is_eq(&self, other: &dyn MersData) -> bool {
@@ -21,7 +21,7 @@ impl MersData for Reference {
         Box::new(Clone::clone(self))
     }
     fn as_type(&self) -> Type {
-        Type::new(ReferenceT(self.0.write().unwrap().get().as_type()))
+        Type::new(ReferenceT(self.1.clone()))
     }
     fn as_any(&self) -> &dyn Any {
         self
diff --git a/mers_lib/src/program/configs/with_list.rs b/mers_lib/src/program/configs/with_list.rs
index 25550c5..747be08 100755
--- a/mers_lib/src/program/configs/with_list.rs
+++ b/mers_lib/src/program/configs/with_list.rs
@@ -46,7 +46,7 @@ impl Config {
                                         if let Some(t) = t.0[0].dereference() {
                                             for t in t.types.iter() {
                                                 if let Some(t) = t.as_any().downcast_ref::<ListT>() {
-                                                    out.add(Arc::new(data::reference::ReferenceT(t.0.clone())));
+                                                    out.add(Arc::new(data::tuple::TupleT(vec![Type::new(data::reference::ReferenceT(t.0.clone()))])));
                                                 } else {
                                                     return Err(format!(
                                                         "get_mut: first argument in tuple {t} isn't `&List<_>`."
@@ -75,20 +75,21 @@ impl Config {
                         let t = a.get();
                         let t = t.as_any().downcast_ref::<data::tuple::Tuple>().unwrap();
                         let i = t.0[1].get().as_any().downcast_ref::<data::int::Int>().unwrap().0.max(0) as usize;
-                        let o = match t.0[0].get()
+                        let list = t.0[0].get();
+                        let list = &list
                             .as_any()
                             .downcast_ref::<data::reference::Reference>()
-                            .unwrap()
-                            .0
+                            .unwrap().0;
+                        let list = list
                             .read()
-                            .unwrap()
-                            .get()
-                            .as_any()
+                            .unwrap();
+                        let list = list.get();
+                        let list = list.as_any()
                             .downcast_ref::<List>()
-                            .unwrap().0.get(i)
-                        {
+                            .unwrap();
+                        let o = match list.0.get(i) {
                             Some(data) => {
-                                Data::new(data::reference::Reference(Arc::clone(data)))
+                                Data::one_tuple(Data::new(data::reference::Reference(Arc::clone(data), list.inner_type())))
                             }
                             None => Data::empty_tuple(),
                         };
@@ -263,11 +264,7 @@ impl MersData for List {
         Box::new(Clone::clone(self))
     }
     fn as_type(&self) -> Type {
-        let mut t = Type::empty();
-        for el in &self.0 {
-            t.add(Arc::new(el.read().unwrap().get().as_type()));
-        }
-        Type::new(ListT(t))
+        Type::new(ListT(self.inner_type()))
     }
     fn as_any(&self) -> &dyn std::any::Any {
         self
@@ -332,3 +329,12 @@ impl Display for ListT {
         Ok(())
     }
 }
+impl List {
+    pub fn inner_type(&self) -> Type {
+        let mut t = Type::empty();
+        for el in &self.0 {
+            t.add(Arc::new(el.read().unwrap().get().as_type()));
+        }
+        t
+    }
+}
diff --git a/mers_lib/src/program/run/variable.rs b/mers_lib/src/program/run/variable.rs
index 38fba55..34e15a8 100755
--- a/mers_lib/src/program/run/variable.rs
+++ b/mers_lib/src/program/run/variable.rs
@@ -60,15 +60,18 @@ impl MersStatement for Variable {
                 info.scopes[self.var.0].vars[self.var.1] = nothing;
             } else {
                 // (reference to) data which will never be referenced again
-                return Data::new(data::reference::Reference(Arc::new(RwLock::new(
-                    Data::empty_tuple(),
-                ))));
+                return Data::new(data::reference::Reference(
+                    Arc::new(RwLock::new(Data::empty_tuple())),
+                    Type::empty(),
+                ));
             }
         }
         if self.is_ref_not_ignore {
-            Data::new(data::reference::Reference(Arc::clone(
-                &info.scopes[self.var.0].vars[self.var.1],
-            )))
+            let v = &info.scopes[self.var.0].vars[self.var.1];
+            Data::new(data::reference::Reference(
+                Arc::clone(v),
+                v.read().unwrap().get().as_type(),
+            ))
         } else {
             info.scopes[self.var.0].vars[self.var.1]
                 .write()