fix: object assignment from multitype

mers/Cargo.toml

@@ -15,7 +15,7 @@ default = ["colored-output"]
 colored-output = ["mers_lib/ecolor-term", "mers_lib/pretty-print", "dep:colored"]
 
 [dependencies]
-mers_lib = "0.9.23"
+mers_lib = "0.9.24"
 # mers_lib = { path = "../mers_lib" }
 clap = { version = "4.3.19", features = ["derive"] }
 colored = { version = "2.1.0", optional = true }

mers_lib/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mers_lib"
-version = "0.9.23"
+version = "0.9.24"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "library to use the mers language in other projects"

mers_lib/src/program/run/object.rs

@@ -24,18 +24,65 @@ impl MersStatement for Object {
             let print_is_part_of = init_to.types.len() > 1;
             let mut init_fields = HashMap::new();
             for t in init_to.types.iter() {
-                if let Some(t) = t.as_any().downcast_ref::<ObjectT>() {
+                if let Some(ot) = t.as_any().downcast_ref::<ObjectT>() {
-                    for (field, t) in t.iter() {
+                    let mut fields = self.fields.iter().map(|(t, _)| *t).collect::<Vec<_>>();
+                    fields.sort();
+                    for (field, t) in ot.iter() {
+                        if let Ok(i) = fields.binary_search(field) {
+                            fields.remove(i);
+                        }
                         init_fields
                             .entry(*field)
                             .or_insert_with(Type::empty)
                             .add_all(t);
                     }
+                    if !fields.is_empty() {
+                        return Err(CheckError::new().msg(vec![
+                            ("can't init an ".to_owned(), None),
+                            ("object".to_owned(), Some(EColor::InitTo)),
+                            (" from type ".to_owned(), None),
+                            (t.simplified_as_string(info), Some(EColor::InitFrom)),
+                            if print_is_part_of {
+                                (", which is part of ".to_owned(), None)
+                            } else {
+                                (format!(""), None)
+                            },
+                            if print_is_part_of {
+                                (init_to.simplified_as_string(info), Some(EColor::InitFrom))
+                            } else {
+                                (format!(""), None)
+                            },
+                            (
+                                format!(" - missing fields {}", {
+                                    let object_fields_rev =
+                                        info.global.object_fields_rev.lock().unwrap();
+                                    fields
+                                        .iter()
+                                        .map(|f| {
+                                            object_fields_rev
+                                                .get(*f)
+                                                .map(|f| f.as_str())
+                                                .unwrap_or("<unknown>")
+                                        })
+                                        .enumerate()
+                                        .map(|(i, f)| {
+                                            if i == 0 {
+                                                f.to_owned()
+                                            } else {
+                                                format!(", {f}")
+                                            }
+                                        })
+                                        .collect::<String>()
+                                }),
+                                None,
+                            ),
+                        ]));
+                    }
                 } else {
                     return Err(CheckError::new().msg(vec![
                         ("can't init an ".to_owned(), None),
                         ("object".to_owned(), Some(EColor::InitTo)),
-                        (" with type ".to_owned(), None),
+                        (" from type ".to_owned(), None),
                         (t.simplified_as_string(info), Some(EColor::InitFrom)),
                         if print_is_part_of {
                             (", which is part of ".to_owned(), None)
@@ -72,22 +119,7 @@ impl MersStatement for Object {
                                 } else if init_to_is_empty_type {
                                     Type::empty()
                                 } else {
-                                    return Err(CheckError::new().msg(vec![
+                                    unreachable!("type-checking earlier in check_custom() should prevent this")
-                                        ("can't init an ".to_owned(), None),
-                                        ("object".to_owned(), Some(EColor::InitTo)),
-                                        (" with type ".to_owned(), None),
-                                        (
-                                            init_to.as_ref().unwrap().simplified_as_string(info),
-                                            Some(EColor::InitFrom),
-                                        ),
-                                        (
-                                            format!(
-                                                " - field {} is missing",
-                                                info.display_info().get_object_field_name(*field)
-                                            ),
-                                            None,
-                                        ),
-                                    ]));
                                 })
                             } else {
                                 None