nac3artiq/demo/min_artiq.py

@@ -11,6 +11,7 @@ from embedding_map import EmbeddingMap
 
 __all__ = [
     "Kernel", "KernelInvariant", "virtual",
+    "Option", "Some",
     "round64", "floor64", "ceil64",
     "extern", "kernel", "portable", "nac3",
     "rpc", "ms", "us", "ns",
@@ -32,6 +33,36 @@ class KernelInvariant(Generic[T]):
 class virtual(Generic[T]):
     pass
 
+class Option(Generic[T]):
+    _nac3_option: T
+
+    def __init__(self, v: T):
+        self._nac3_option = v
+
+    def is_none(self):
+        return self._nac3_option is None
+    
+    def is_some(self):
+        return not self.is_none()
+    
+    def unwrap(self):
+        return self._nac3_option
+
+    def __repr__(self) -> str:
+        if self.is_none():
+            return "Option(None)"
+        else:
+            return "Some({})".format(repr(self._nac3_option))
+    
+    def __str__(self) -> str:
+        if self.is_none():
+            return "None"
+        else:
+            return "Some({})".format(str(self._nac3_option))
+
+def Some(v: T) -> Option[T]:
+    return Option(v)
+
 
 def round64(x):
     return round(x)

nac3artiq/src/lib.rs

@@ -71,6 +71,7 @@ pub struct PrimitivePythonId {
     exception: u64,
     generic_alias: (u64, u64),
     virtual_id: u64,
+    option: u64,
 }
 
 type TopLevelComponent = (Stmt, String, PyObject);
@@ -352,6 +353,7 @@ impl Nac3 {
 
         let builtins_mod = PyModule::import(py, "builtins").unwrap();
         let id_fn = builtins_mod.getattr("id").unwrap();
+        let type_fn = builtins_mod.getattr("type").unwrap();
         let numpy_mod = PyModule::import(py, "numpy").unwrap();
         let typing_mod = PyModule::import(py, "typing").unwrap();
         let types_mod = PyModule::import(py, "types").unwrap();
@@ -373,7 +375,11 @@ impl Nac3 {
                 get_attr_id(typing_mod, "_GenericAlias"),
                 get_attr_id(types_mod, "GenericAlias"),
             ),
-            none: get_attr_id(builtins_mod, "None"),
+            none: id_fn
+                .call1((type_fn.call1((builtins_mod.getattr("None").unwrap(),)).unwrap(),))
+                .unwrap()
+                .extract()
+                .unwrap(),
             typevar: get_attr_id(typing_mod, "TypeVar"),
             int: get_attr_id(builtins_mod, "int"),
             int32: get_attr_id(numpy_mod, "int32"),
@@ -385,6 +391,17 @@ impl Nac3 {
             list: get_attr_id(builtins_mod, "list"),
             tuple: get_attr_id(builtins_mod, "tuple"),
             exception: get_attr_id(builtins_mod, "Exception"),
+            option: id_fn
+                .call1((builtins_mod
+                    .getattr("globals")
+                    .unwrap()
+                    .call0()
+                    .unwrap()
+                    .get_item("Option")
+                    .unwrap(),))
+                .unwrap()
+                .extract()
+                .unwrap(),
         };
 
         let working_directory = tempfile::Builder::new().prefix("nac3-").tempdir().unwrap();

nac3artiq/src/symbol_resolver.rs

@@ -279,6 +279,27 @@ impl InnerResolver {
         } else if ty_id == self.primitive_ids.tuple {
             // do not handle type var param and concrete check here
             Ok(Ok((unifier.add_ty(TypeEnum::TTuple { ty: vec![] }), false)))
+        } else if ty_id == self.primitive_ids.option {
+            Ok(Ok((primitives.option, false)))
+        } else if ty_id == self.primitive_ids.none {
+            if let TypeEnum::TObj { params, .. } =
+                unifier.get_ty_immutable(primitives.option).as_ref()
+            {
+                let var_map = params
+                    .iter()
+                    .map(|(id_var, ty)| {
+                        if let TypeEnum::TVar { id, range, name, loc, .. } = &*unifier.get_ty(*ty) {
+                            assert_eq!(*id, *id_var);
+                            (*id, unifier.get_fresh_var_with_range(range, *name, *loc).0)
+                        } else {
+                            unreachable!()
+                        }
+                    })
+                    .collect::<HashMap<_, _>>();
+                Ok(Ok((unifier.subst(primitives.option, &var_map).unwrap(), true)))
+            } else {
+                unreachable!("must be tobj")
+            }
         } else if let Some(def_id) = self.pyid_to_def.read().get(&ty_id).cloned() {
             let def = defs[def_id.0].read();
             if let TopLevelDef::Class { object_id, type_vars, fields, methods, .. } = &*def {
@@ -569,6 +590,34 @@ impl InnerResolver {
                 let types = types?;
                 Ok(types.map(|types| unifier.add_ty(TypeEnum::TTuple { ty: types })))
             }
+            // special handling for option type since its class member layout in python side
+            // is special and cannot be mapped directly to a nac3 type as below
+            (TypeEnum::TObj { obj_id, params, .. }, false)
+                if *obj_id == primitives.option.get_obj_id(unifier) =>
+            {
+                let field_data = match obj.getattr("_nac3_option") {
+                    Ok(d) => d,
+                    // None should be already handled above
+                    Err(_) => unreachable!("cannot be None")
+                };
+                let field_obj_id: u64 = self.helper.id_fn.call1(py, (field_data,))?.extract(py)?;
+                let zelf_obj_id: u64 = self.helper.id_fn.call1(py, (obj,))?.extract(py)?;
+                if field_obj_id == zelf_obj_id {
+                    return Ok(Err("self recursive option type is not allowed".into()))
+                }
+                let ty = match self.get_obj_type(py, field_data, unifier, defs, primitives)? {
+                    Ok(t) => t,
+                    Err(e) => {
+                        return Ok(Err(format!(
+                            "error when getting type of the option object ({})",
+                            e
+                        )))
+                    }
+                };
+                let new_var_map: HashMap<_, _> = params.iter().map(|(id, _)| (*id, ty)).collect();
+                let res = unifier.subst(extracted_ty, &new_var_map).unwrap_or(extracted_ty);
+                Ok(Ok(res))
+            }
             (TypeEnum::TObj { params, fields, .. }, false) => {
                 let var_map = params
                     .iter()
@@ -795,6 +844,37 @@ impl InnerResolver {
             let global = ctx.module.add_global(ty, Some(AddressSpace::Generic), &id_str);
             global.set_initializer(&val);
             Ok(Some(global.as_pointer_value().into()))
+        } else if ty_id == self.primitive_ids.option {
+            match self
+                .get_obj_value(py, obj.getattr("_nac3_option").unwrap(), ctx, generator)
+                .map_err(|e| {
+                    super::CompileError::new_err(format!(
+                        "Error getting value of Option object: {}",
+                        e
+                    ))
+                })? {
+                Some(v) => {
+                    let global_str = format!("{}_option", id);
+                    {
+                        if self.global_value_ids.read().contains(&id) {
+                            let global = ctx.module.get_global(&global_str).unwrap_or_else(|| {
+                                ctx.module.add_global(v.get_type(), Some(AddressSpace::Generic), &global_str)
+                            });
+                            return Ok(Some(global.as_pointer_value().into()));
+                        } else {
+                            self.global_value_ids.write().insert(id);
+                        }
+                    }
+                    let global = ctx.module.add_global(v.get_type(), Some(AddressSpace::Generic), &global_str);
+                    global.set_initializer(&v);
+                    Ok(Some(global.as_pointer_value().into()))
+                },
+                None => Ok(None),
+            }
+        } else if ty_id == self.primitive_ids.none {
+            // for option type, just a null ptr, whose type needs to be casted in codegen
+            // according to the type info attached in the ast
+            Ok(Some(ctx.ctx.i8_type().ptr_type(AddressSpace::Generic).const_null().into()))
         } else {
             let id_str = id.to_string();
 

nac3core/src/codegen/expr.rs

@@ -958,16 +958,27 @@ pub fn gen_expr<'ctx, 'a, G: CodeGenerator>(
                 let resolver = ctx.resolver.clone();
                 let val = resolver.get_symbol_value(*id, ctx).unwrap();
                 // if is tuple, need to deref it to handle tuple as value
-                if let (TypeEnum::TTuple { .. }, BasicValueEnum::PointerValue(ptr)) = (
+                // if is option, need to cast pointer to handle None
+                match (
                     &*ctx.unifier.get_ty(expr.custom.unwrap()),
                     resolver
                         .get_symbol_value(*id, ctx)
                         .unwrap()
                         .to_basic_value_enum(ctx, generator)?,
                 ) {
-                    ctx.builder.build_load(ptr, "tup_val").into()
-                } else {
-                    val
+                    (TypeEnum::TTuple { .. }, BasicValueEnum::PointerValue(ptr)) => {
+                        ctx.builder.build_load(ptr, "tup_val").into()
+                    }
+                    (TypeEnum::TObj { obj_id, params, .. }, BasicValueEnum::PointerValue(ptr))
+                        if *obj_id == ctx.primitives.option.get_obj_id(&ctx.unifier) => {
+                            let actual_ptr_ty = ctx.get_llvm_type(
+                                generator,
+                                *params.iter().next().unwrap().1,
+                            )
+                            .ptr_type(AddressSpace::Generic);
+                            ctx.builder.build_bitcast(ptr, actual_ptr_ty, "option_ptr_cast").into()
+                        }
+                    _ => val,
                 }
             }
         },

nac3core/src/codegen/mod.rs

@@ -270,7 +270,7 @@ fn get_llvm_type<'ctx>(
         let result = match &*ty_enum {
             TObj { obj_id, fields, .. } => {
                 // check to avoid treating primitives other than Option as classes
-                if obj_id.0 <= 14 {
+                if obj_id.0 <= 10 {
                     match (unifier.get_ty(ty).as_ref(), unifier.get_ty(primitives.option).as_ref())
                     {
                         (

nac3core/src/typecheck/typedef/mod.rs

@@ -54,6 +54,18 @@ pub enum RecordKey {
     Int(i32),
 }
 
+impl Type {
+    // a wrapper function for cleaner code so that we don't need to
+    // write this long pattern matching just to get the field `obj_id`
+    pub fn get_obj_id(self, unifier: &Unifier) -> DefinitionId {
+        if let TypeEnum::TObj { obj_id, .. } = unifier.get_ty_immutable(self).as_ref() {
+            *obj_id
+        } else {
+            unreachable!("expect a object type")
+        }
+    }
+}
+
 impl From<&RecordKey> for StrRef {
     fn from(r: &RecordKey) -> Self {
         match r {