Execution Context (https://github.com/enso-org/ide/pull/419)

This PR introduces Executed Graph Controller, which is a Graph Controller with additional info about execution context.

Original commit: 026a2585ae

gui/src/rust/ide/enso-protocol/src/language_server.rs

@@ -130,14 +130,14 @@ trait API {
     fn destroy_execution_context(&self, context_id:ContextId) -> ();
 
     /// Move the execution context to a new location deeper down the stack.
-    #[MethodInput=PushExecutionContextInput,rpc_name="executionContext/push",
+    #[MethodInput=PushToExecutionContextInput,rpc_name="executionContext/push",
-    result=push_execution_context_result,set_result=set_push_execution_context_result]
+    result=push_to_execution_context_result,set_result=set_push_to_execution_context_result]
-    fn push_execution_context(&self, context_id:ContextId, stack_item:StackItem) -> ();
+    fn push_to_execution_context(&self, context_id:ContextId, stack_item:StackItem) -> ();
 
     /// Move the execution context up the stack.
-    #[MethodInput=PopExecutionContextInput,rpc_name="executionContext/pop",
+    #[MethodInput=PopFromExecutionContextInput,rpc_name="executionContext/pop",
-    result=pop_execution_context_result,set_result=set_pop_execution_context_result]
+    result=pop_from_execution_context_result,set_result=set_pop_from_execution_context_result]
-    fn pop_execution_context(&self, context_id:ContextId) -> ();
+    fn pop_from_execution_context(&self, context_id:ContextId) -> ();
 
     /// Attach a visualisation, potentially preprocessed by some arbitrary Enso code, to a given
     /// node in the program.

gui/src/rust/ide/enso-protocol/src/language_server/response.rs

@@ -52,6 +52,7 @@ pub struct OpenTextFile {
 #[serde(rename_all = "camelCase")]
 #[allow(missing_docs)]
 pub struct CreateExecutionContext {
+    pub context_id       : ContextId,
     pub can_modify       : CapabilityRegistration,
     pub receives_updates : CapabilityRegistration
 }

gui/src/rust/ide/enso-protocol/src/language_server/tests.rs

@@ -322,12 +322,13 @@ fn test_execution_context() {
     let method           = "executionContext/receivesUpdates".to_string();
     let receives_updates = CapabilityRegistration{method,register_options};
     let create_execution_context_response = response::CreateExecutionContext
-    {can_modify,receives_updates};
+    {context_id,can_modify,receives_updates};
     test_request(
         |client| client.create_execution_context(),
         "executionContext/create",
         json!({}),
         json!({
+            "contextId" : "00000000-0000-0000-0000-000000000000",
             "canModify" : {
                 "method"          : "executionContext/canModify",
                 "registerOptions" : {
@@ -354,7 +355,7 @@ fn test_execution_context() {
     let local_call    = LocalCall {expression_id};
     let stack_item    = StackItem::LocalCall(local_call);
     test_request(
-        |client| client.push_execution_context(context_id,stack_item),
+        |client| client.push_to_execution_context(context_id,stack_item),
         "executionContext/push",
         json!({
             "contextId" : "00000000-0000-0000-0000-000000000000",
@@ -367,7 +368,7 @@ fn test_execution_context() {
         ()
     );
     test_request(
-        |client| client.pop_execution_context(context_id),
+        |client| client.pop_from_execution_context(context_id),
         "executionContext/pop",
         json!({"contextId":"00000000-0000-0000-0000-000000000000"}),
         unit_json.clone(),

gui/src/rust/ide/enso-protocol/src/language_server/types.rs

@@ -24,6 +24,7 @@ pub struct Path {
     pub root_id:Uuid,
     /// Path's segments.
     pub segments:Vec<String>,
+
 }
 
 impl Display for Path {
@@ -34,12 +35,24 @@ impl Display for Path {
 }
 
 impl Path {
+    /// Returns the file name, i.e. the last segment if exists.
+    pub fn file_name(&self) -> Option<&String> {
+        self.segments.last()
+    }
+
     /// Returns the file extension, i.e. the part of last path segment after the last dot.
     /// Returns `None` is there is no segments or no dot in the last segment.
     pub fn extension(&self) -> Option<&str> {
-        let segment = self.segments.last()?;
+        let name           = self.file_name()?;
-        let last_dot_index = segment.rfind('.')?;
+        let last_dot_index = name.rfind('.')?;
-        Some(&segment[last_dot_index + 1..])
+        Some(&name[last_dot_index + 1..])
+    }
+
+    /// Returns the stem of filename, i.e. part of last segment without extension if present.
+    pub fn file_stem(&self) -> Option<&str> {
+        let name        = self.file_name()?;
+        let name_length = name.rfind('.').unwrap_or_else(|| name.len());
+        Some(&name[..name_length])
     }
 
     /// Constructs a new path from given root ID and segments.

gui/src/rust/ide/json-rpc/src/macros.rs

@@ -112,15 +112,18 @@ macro_rules! make_rpc_methods {
         /// Mock used for tests.
         #[derive(Debug,Default)]
         pub struct MockClient {
-            $($method_result : RefCell<HashMap<($($param_ty),*),Result<$result>>>,)*
+            expect_all_calls : Cell<bool>,
+            $($method_result : RefCell<HashMap<($($param_ty),*),Vec<Result<$result>>>>,)*
         }
 
         impl API for MockClient {
             $(fn $method(&self $(,$param_name:$param_ty)*)
             -> std::pin::Pin<Box<dyn Future<Output=Result<$result>>>> {
-                let mut result = self.$method_result.borrow_mut();
+                let mut results = self.$method_result.borrow_mut();
-                let result     = result.remove(&($($param_name),*)).unwrap();
+                let params      = ($($param_name),*);
-                Box::pin(async move { result })
+                let result      = results.get_mut(&params).and_then(|res| res.pop());
+                let err         = format!("Unrecognized call {} with params {:?}",$rpc_name,params);
+                Box::pin(futures::future::ready(result.expect(err.as_str())))
             })*
         }
 
@@ -128,9 +131,30 @@ macro_rules! make_rpc_methods {
             $(
                 /// Sets `$method`'s result to be returned when it is called.
                 pub fn $set_result(&self $(,$param_name:$param_ty)*, result:Result<$result>) {
-                    self.$method_result.borrow_mut().insert(($($param_name),*),result);
+                    let mut results = self.$method_result.borrow_mut();
+                    let mut entry   = results.entry(($($param_name),*));
+                    entry.or_default().push(result);
+                }
+            )*
+
+            /// Mark all calls defined by `set_$method_result` as required. If client will be
+            /// dropped without calling the test will fail.
+            pub fn expect_all_calls(&self) {
+                self.expect_all_calls.set(true);
+            }
+        }
+
+        impl Drop for MockClient {
+            fn drop(&mut self) {
+                if self.expect_all_calls.get() {
+                    $(
+                        for (params,results) in self.$method_result.borrow().iter() {
+                            assert!(results.is_empty(), "Didn't make expected call {} with \
+                            parameters {:?}",$rpc_name,params);
                         }
                     )*
                 }
             }
+        }
+    }
 }

gui/src/rust/ide/src/controller.rs

@@ -21,6 +21,16 @@ pub mod project;
 pub mod text;
 
 pub use graph::Handle           as Graph;
+pub use graph::executed::Handle as ExecutedGraph;
 pub use module::Handle          as Module;
 pub use project::Handle         as Project;
 pub use text::Handle            as Text;
+
+
+
+// ============
+// === Path ===
+// ============
+
+/// Path to a file on disc, used across all controllers
+pub type FilePath = enso_protocol::language_server::Path;

gui/src/rust/ide/src/controller/graph.rs

@@ -2,6 +2,7 @@
 //!
 //! This controller provides access to a specific graph. It lives under a module controller, as
 //! each graph belongs to some module.
+pub mod executed;
 
 use crate::prelude::*;
 
@@ -23,7 +24,6 @@ use span_tree::SpanTree;
 use ast::crumbs::InfixCrumb;
 
 
-
 // ==============
 // === Errors ===
 // ==============
@@ -395,8 +395,6 @@ pub struct Handle {
 impl Handle {
 
     /// Creates a new controller. Does not check if id is valid.
-    ///
-    /// Requires global executor to spawn the events relay task.
     pub fn new_unchecked(module:Rc<model::Module>, parser:Parser, id:Id) -> Handle {
         let id     = Rc::new(id);
         let logger = Logger::new(format!("Graph Controller {}", id));
@@ -405,8 +403,6 @@ impl Handle {
 
     /// Creates a new graph controller. Given ID should uniquely identify a definition in the
     /// module. Fails if ID cannot be resolved.
-    ///
-    /// Requires global executor to spawn the events relay task.
     pub fn new(module:Rc<model::Module>, parser:Parser, id:Id) -> FallibleResult<Handle> {
         let ret = Self::new_unchecked(module,parser,id);
         // Get and discard definition info, we are just making sure it can be obtained.
@@ -751,7 +747,7 @@ mod tests {
               Fut  : Future<Output=()> {
             let code     = code.as_ref();
             let ls       = language_server::Connection::new_mock_rc(default());
-            let path     = controller::module::Path::new(default(),&["Main"]);
+            let path     = controller::module::Path::from_module_name("Main");
             let parser   = Parser::new_or_panic();
             let module   = controller::Module::new_mock(path,code,default(),ls,parser).unwrap();
             let graph_id = Id::new_single_crumb(DefinitionName::new_plain(function_name.into()));
@@ -766,7 +762,7 @@ mod tests {
                   Fut  : Future<Output=()> {
             let code   = code.as_ref();
             let ls     = language_server::Connection::new_mock_rc(default());
-            let path   = controller::module::Path::new(default(),&["Main"]);
+            let path   = controller::module::Path::from_module_name("Main");
             let parser = Parser::new_or_panic();
             let module = controller::Module::new_mock(path, code, default(), ls, parser).unwrap();
             let graph  = module.graph_controller(graph_id).unwrap();

gui/src/rust/ide/src/controller/graph/executed.rs

@@ -0,0 +1,30 @@
+//! A module with Executed Graph Controller.
+//!
+//! This controller provides operations on a specific graph with some execution context - these
+//! operations usually involves retrieving values on nodes: that's are i.e. operations on
+//! visualisations, retrieving types on ports, etc.
+use crate::prelude::*;
+
+use crate::model::synchronized::ExecutionContext;
+
+/// Handle providing executed graph controller interface.
+#[derive(Clone,CloneRef,Debug)]
+pub struct Handle {
+    /// A handle to basic graph operations.
+    pub graph     : controller::Graph,
+    execution_ctx : Rc<ExecutionContext>,
+}
+
+impl Handle {
+    /// Create handle for given graph and execution context.
+    ///
+    /// This takes ownership of execution context which will be shared between all copies of this
+    /// handle; when all copies will be dropped, the execution context will be dropped as well
+    /// (and will then removed from LanguageServer).
+    pub fn new(graph:controller::Graph, execution_ctx:ExecutionContext) -> Self {
+        let execution_ctx = Rc::new(execution_ctx);
+        Handle{graph,execution_ctx}
+    }
+
+    //TODO[ao] Here goes the methods requiring ContextId
+}

gui/src/rust/ide/src/controller/module.rs

@@ -7,7 +7,9 @@
 
 use crate::prelude::*;
 
+use crate::controller::FilePath;
 use crate::double_representation::text::apply_code_change_to_id_map;
+use crate::model::synchronized::ExecutionContext;
 
 use ast;
 use ast::HasIdMap;
@@ -15,6 +17,23 @@ use data::text::*;
 use double_representation as dr;
 use enso_protocol::language_server;
 use parser::Parser;
+use failure::_core::fmt::Formatter;
+
+
+
+// ==============
+// === Errors ===
+// ==============
+
+/// Error returned when module path is invalid, i.e. cannot obtain module name from it.
+#[derive(Clone,Copy,Debug,Fail)]
+#[fail(display="Invalid module path.")]
+pub struct InvalidModulePath {}
+
+/// Error returned when graph id invalid.
+#[derive(Clone,Debug,Fail)]
+#[fail(display="Invalid graph id: {:?}.",_0)]
+pub struct InvalidGraphId(controller::graph::Id);
 
 
 
@@ -23,7 +42,55 @@ use parser::Parser;
 // ============
 
 /// Path identifying module's file in the Language Server.
-pub type Path = language_server::Path;
+#[derive(Clone,Debug,Eq,Hash,PartialEq)]
+pub struct Path {
+    file_path : FilePath,
+}
+
+impl Path {
+    /// Create a path from the file path. Returns None if given path is not a valid module file.
+    pub fn from_file_path(file_path:FilePath) -> Option<Self> {
+        let has_proper_ext   = file_path.extension() == Some(constants::LANGUAGE_FILE_EXTENSION);
+        let capitalized_name = file_path.file_name()?.chars().next()?.is_uppercase();
+        let is_module        = has_proper_ext && capitalized_name;
+        is_module.and_option_from(|| Some(Path{file_path}))
+    }
+
+    /// Get the file path.
+    pub fn file_path(&self) -> &FilePath {
+        &self.file_path
+    }
+
+    /// Get the module name from path.
+    ///
+    /// The module name is a filename without extension.
+    pub fn module_name(&self) -> &str {
+        // The file stem existence should be checked during construction.
+        self.file_path.file_stem().unwrap()
+    }
+    /// Create a module path consisting of a single segment, based on a given module name.
+    #[cfg(test)]
+    pub fn from_module_name(name:impl Str) -> Self {
+        let name:String = name.into();
+        let file_name   = format!("{}.{}",name,constants::LANGUAGE_FILE_EXTENSION);
+        let file_path   = FilePath::new(default(),&[file_name]);
+        Self::from_file_path(file_path).unwrap()
+    }
+}
+
+impl TryFrom<FilePath> for Path {
+    type Error = InvalidModulePath;
+
+    fn try_from(value:FilePath) -> Result<Self, Self::Error> {
+        Path::from_file_path(value).ok_or(InvalidModulePath{})
+    }
+}
+
+impl Display for Path {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.file_path, f)
+    }
+}
 
 
 
@@ -59,7 +126,7 @@ impl Handle {
     /// Load or reload module content from file.
     pub async fn load_file(&self) -> FallibleResult<()> {
         self.logger.info(|| "Loading module file");
-        let path    = self.path.deref().clone();
+        let path    = self.path.file_path().clone();
         let content = self.language_server.client.read_file(path).await?.contents;
         self.logger.info(|| "Parsing code");
         // TODO[ao] We should not fail here when metadata are malformed, but discard them and set
@@ -73,7 +140,7 @@ impl Handle {
 
     /// Save the module to file.
     pub fn save_file(&self) -> impl Future<Output=FallibleResult<()>> {
-        let path    = self.path.deref().clone();
+        let path    = self.path.file_path().clone();
         let ls      = self.language_server.clone();
         let content = self.model.source_as_string();
         async move { Ok(ls.client.write_file(path,content?).await?) }
@@ -122,6 +189,20 @@ impl Handle {
         controller::Graph::new(self.model.clone_ref(), self.parser.clone_ref(), id)
     }
 
+    /// Returns a executed graph controller for graph in this module's subtree identified by id.
+    /// The execution context will be rooted at definition of this graph.
+    ///
+    /// This function wont check if the definition under id exists.
+    pub async fn executed_graph_controller_unchecked
+    (&self, id:dr::graph::Id) -> FallibleResult<controller::ExecutedGraph> {
+        let definition_name = id.crumbs.last().cloned().ok_or_else(|| InvalidGraphId(id.clone()))?;
+        let graph           = self.graph_controller_unchecked(id);
+        let language_server = self.language_server.clone_ref();
+        let path            = self.path.clone_ref();
+        let execution_ctx   = ExecutionContext::create(language_server,path,definition_name).await?;
+        Ok(controller::ExecutedGraph::new(graph,execution_ctx))
+    }
+
     /// Returns a graph controller for graph in this module's subtree identified by `id` without
     /// checking if the graph exists.
     pub fn graph_controller_unchecked(&self, id:dr::graph::Id) -> controller::Graph {
@@ -167,17 +248,28 @@ mod test {
     use ast::BlockLine;
     use ast::Ast;
     use data::text::Span;
-    use enso_protocol::language_server;
     use parser::Parser;
     use uuid::Uuid;
     use wasm_bindgen_test::wasm_bindgen_test;
 
+    #[test]
+    fn module_path_conversion() {
+        let path = FilePath::new(default(), &["src","Main.enso"]);
+        assert!(Path::from_file_path(path).is_some());
+
+        let path = FilePath::new(default(), &["src","Main.txt"]);
+        assert!(Path::from_file_path(path).is_none());
+
+        let path = FilePath::new(default(), &["src","main.txt"]);
+        assert!(Path::from_file_path(path).is_none());
+    }
+
     #[wasm_bindgen_test]
     fn update_ast_after_text_change() {
         TestWithLocalPoolExecutor::set_up().run_task(async {
             let ls       = language_server::Connection::new_mock_rc(default());
             let parser   = Parser::new().unwrap();
-            let location = Path{root_id:default(),segments:vec!["Test".into()]};
+            let location = Path::from_module_name("Test");
 
             let uuid1    = Uuid::new_v4();
             let uuid2    = Uuid::new_v4();

gui/src/rust/ide/src/controller/project.rs

@@ -5,6 +5,8 @@
 
 use crate::prelude::*;
 
+use crate::controller::FilePath;
+
 use enso_protocol::language_server;
 use parser::Parser;
 
@@ -40,9 +42,8 @@ impl Handle {
     /// Returns a text controller for a given file path.
     ///
     /// It supports both modules and plain text files.
-    pub async fn text_controller
+    pub async fn text_controller(&self, path:FilePath) -> FallibleResult<controller::Text> {
-    (&self, path:language_server::Path) -> FallibleResult<controller::Text> {
+        if let Some(path) = controller::module::Path::from_file_path(path.clone()) {
-        if is_path_to_module(&path) {
             trace!(self.logger,"Obtaining controller for module {path}");
             let module = self.module_controller(path).await?;
             Ok(controller::Text::new_for_module(module))
@@ -77,16 +78,16 @@ impl Handle {
     }
 }
 
-/// Checks if the given path looks like it is referring to module file.
+
-fn is_path_to_module(path:&language_server::Path) -> bool {
+
-    path.extension() == Some(constants::LANGUAGE_FILE_EXTENSION)
+// ============
-}
+// === Test ===
+// ============
 
 #[cfg(test)]
 mod test {
     use super::*;
 
-    use crate::controller::text::FilePath;
     use crate::executor::test_utils::TestWithLocalPoolExecutor;
 
     use language_server::response;
@@ -96,28 +97,20 @@ mod test {
 
     wasm_bindgen_test_configure!(run_in_browser);
 
-
-    #[test]
-    fn is_path_to_module_test() {
-        let path = language_server::Path::new(default(), &["src","Main.enso"]);
-        assert!(is_path_to_module(&path));
-
-        let path = language_server::Path::new(default(), &["src","Main.txt"]);
-        assert_eq!(is_path_to_module(&path), false);
-    }
-
     #[wasm_bindgen_test]
     fn obtain_module_controller() {
         let mut test  = TestWithLocalPoolExecutor::set_up();
         test.run_task(async move {
-            let path         = ModulePath{root_id:default(),segments:vec!["TestLocation".into()]};
+            let path         = ModulePath::from_module_name("TestModule");
-            let another_path = ModulePath{root_id:default(),segments:vec!["TestLocation2".into()]};
+            let another_path = ModulePath::from_module_name("TestModule2");
 
             let client    = language_server::MockClient::default();
             let contents  = "2+2".to_string();
-            client.set_file_read_result(path.clone(),Ok(response::Read{contents}));
+            let file_path = path.file_path().clone();
+            client.set_file_read_result(file_path,Ok(response::Read{contents}));
+            let file_path = another_path.file_path().clone();
             let contents  = "2 + 2".to_string();
-            client.set_file_read_result(another_path.clone(),Ok(response::Read{contents}));
+            client.set_file_read_result(file_path,Ok(response::Read{contents}));
             let connection     = language_server::Connection::new_mock(client);
             let project        = controller::Project::new(connection);
             let module         = project.module_controller(path.clone()).await.unwrap();
@@ -136,8 +129,8 @@ mod test {
             let connection   = language_server::Connection::new_mock(default());
             let project_ctrl = controller::Project::new(connection);
             let root_id      = default();
-            let path         = FilePath{root_id,segments:vec!["TestPath".into()]};
+            let path         = FilePath::new(root_id,&["TestPath"]);
-            let another_path = FilePath{root_id,segments:vec!["TestPath2".into()]};
+            let another_path = FilePath::new(root_id,&["TestPath2"]);
 
             let text_ctrl    = project_ctrl.text_controller(path.clone()).await.unwrap();
             let another_ctrl = project_ctrl.text_controller(another_path.clone()).await.unwrap();
@@ -156,7 +149,7 @@ mod test {
         let mut test = TestWithLocalPoolExecutor::set_up();
         test.run_task(async move {
             let file_name    = format!("test.{}",constants::LANGUAGE_FILE_EXTENSION);
-            let path         = ModulePath{root_id:default(),segments:vec![file_name]};
+            let path         = FilePath::new(default(),&[file_name]);
             let contents     = "2 + 2".to_string();
 
             let client       = language_server::MockClient::default();

gui/src/rust/ide/src/controller/text.rs

@@ -6,6 +6,7 @@
 
 use crate::prelude::*;
 
+use crate::controller::FilePath;
 use crate::notification;
 
 use data::text::TextChange;
@@ -15,15 +16,6 @@ use std::pin::Pin;
 
 
 
-// ============
-// === Path ===
-// ============
-
-/// Path to a file on disc.
-pub type FilePath = language_server::Path;
-
-
-
 // =======================
 // === Text Controller ===
 // =======================
@@ -68,7 +60,7 @@ impl Handle {
     pub fn file_path(&self) -> &FilePath {
         match &self.file {
             FileHandle::PlainText{path,..} => &*path,
-            FileHandle::Module{controller} => &*controller.path,
+            FileHandle::Module{controller} => controller.path.file_path()
         }
     }
 
@@ -162,7 +154,7 @@ mod test {
         let mut test  = TestWithLocalPoolExecutor::set_up();
         test.run_task(async move {
             let ls         = language_server::Connection::new_mock_rc(default());
-            let path       = FilePath{root_id:default(),segments:vec!["test".into()]};
+            let path       = controller::module::Path::from_module_name("Test");
             let parser     = Parser::new().unwrap();
             let module_res = controller::Module::new_mock(path,"main = 2+2",default(),ls,parser);
             let module     = module_res.unwrap();

gui/src/rust/ide/src/double_representation/graph.rs

@@ -13,6 +13,8 @@ use ast::known;
 use utils::fail::FallibleResult;
 use crate::double_representation::connection::Connection;
 
+
+
 /// Graph uses the same `Id` as the definition which introduces the graph.
 pub type Id = double_representation::definition::Id;
 

gui/src/rust/ide/src/model.rs

@@ -1,5 +1,8 @@
 //! The module with structures describing models shared between different controllers.
 
+pub mod execution_context;
 pub mod module;
+pub mod synchronized;
 
+pub use execution_context::ExecutionContext;
 pub use module::Module;

gui/src/rust/ide/src/model/execution_context.rs

@@ -0,0 +1,93 @@
+//! This module consists of all structures describing Execution Context.
+
+use crate::prelude::*;
+
+use crate::double_representation::definition::DefinitionName;
+
+use enso_protocol::language_server;
+
+
+
+// ==============
+// === Errors ===
+// ==============
+
+/// Error then trying to pop stack item on ExecutionContext when there only root call remains.
+#[derive(Clone,Copy,Debug,Fail)]
+#[fail(display="Tried to pop an entry point")]
+pub struct PopOnEmptyStack {}
+
+
+
+// =================
+// === StackItem ===
+// =================
+
+/// An identifier of called definition in module.
+pub type DefinitionId = crate::double_representation::definition::Id;
+/// An identifier of expression.
+pub type ExpressionId = ast::Id;
+
+/// A specific function call occurring within another function's definition body.
+///
+/// This is a single item in ExecutionContext stack.
+#[derive(Clone,Debug,Eq,PartialEq)]
+pub struct LocalCall {
+    /// An expression being a call.
+    pub call       : ExpressionId,
+    /// A definition of function called in `call` expression.
+    pub definition : DefinitionId,
+}
+
+/// An identifier of ExecutionContext.
+pub type Id  = language_server::ContextId;
+
+
+
+// =============
+// === Model ===
+// =============
+
+/// Execution Context Model.
+///
+/// The execution context consists of the root call (which is a direct call of some function
+/// definition) and stack of function calls (see `StackItem` definition and docs).
+///
+/// It implements internal mutability pattern, so the state may be shared between different
+/// controllers.
+#[derive(Debug)]
+pub struct ExecutionContext {
+    /// A name of definition which is a root call of this context.
+    pub entry_point : DefinitionName,
+    stack           : RefCell<Vec<LocalCall>>,
+    //TODO[ao] I think we can put here info about visualisation set as well.
+}
+
+impl ExecutionContext {
+    /// Create new execution context
+    pub fn new(entry_point:DefinitionName) -> Self {
+        let stack = default();
+        Self {entry_point,stack}
+    }
+
+    /// Push a new stack item to execution context.
+    pub fn push(&self, stack_item:LocalCall) {
+        self.stack.borrow_mut().push(stack_item);
+    }
+
+    /// Pop the last stack item from this context. It returns error when only root call
+    /// remains.
+    pub fn pop(&self) -> FallibleResult<()> {
+        self.stack.borrow_mut().pop().ok_or(PopOnEmptyStack{})?;
+        Ok(())
+    }
+
+    /// Get an iterator over stack items.
+    ///
+    /// Because this struct implements _internal mutability pattern_, the stack can actually change
+    /// during iteration. It should not panic, however might give an unpredictable result.
+    pub fn stack_items<'a>(&'a self) -> impl Iterator<Item=LocalCall> + 'a {
+        let stack_size = self.stack.borrow().len();
+        (0..stack_size).filter_map(move |i| self.stack.borrow().get(i).cloned())
+    }
+}

gui/src/rust/ide/src/model/module/registry.rs

@@ -168,7 +168,7 @@ mod test {
             let state    = Rc::new(model::Module::new(ast.try_into().unwrap(),default()));
             let registry = Rc::new(Registry::default());
             let expected = state.clone_ref();
-            let path     = ModulePath::new(default(),&["test"]);
+            let path     = ModulePath::from_module_name("Test");
 
             let loader = async move { Ok(state) };
             let module = registry.get_or_load(path.clone(),loader).await.unwrap();
@@ -188,7 +188,7 @@ mod test {
         let state2    = state1.clone_ref();
         let registry1 = Rc::new(Registry::default());
         let registry2 = registry1.clone_ref();
-        let path1     = ModulePath::new(default(),&["test"]);
+        let path1     = ModulePath::from_module_name("Test");
         let path2     = path1.clone();
 
         let (loaded_send, loaded_recv) = futures::channel::oneshot::channel::<()>();

gui/src/rust/ide/src/model/synchronized.rs

@@ -0,0 +1,6 @@
+//! This module contains synchronising wrappers for models whose state are a reflection of
+//! Language Server state, e.g. modules, execution contexts etc. These wrappers synchronize both
+//! states by notifying Language Server of every change and listening on LanguageServer.
+pub mod execution_context;
+
+pub use execution_context::ExecutionContext;

gui/src/rust/ide/src/model/synchronized/execution_context.rs

@@ -0,0 +1,222 @@
+//! A ExecutionContext model which is synchronized with LanguageServer state.
+
+use crate::prelude::*;
+
+use crate::double_representation::definition::DefinitionName;
+use crate::model::execution_context::LocalCall;
+
+use enso_protocol::language_server;
+use json_rpc::error::RpcError;
+
+
+
+// ==========================
+// === Synchronized Model ===
+// ==========================
+
+/// An ExecutionContext model synchronized with LanguageServer. It will be automatically removed
+/// from LS once dropped.
+#[derive(Debug)]
+pub struct ExecutionContext {
+    id              : model::execution_context::Id,
+    model           : model::ExecutionContext,
+    module_path     : Rc<controller::module::Path>,
+    language_server : Rc<language_server::Connection>,
+    logger          : Logger,
+}
+
+impl ExecutionContext {
+    /// Create new ExecutionContext. It will be created in LanguageServer and the ExplicitCall
+    /// stack frame will be pushed.
+    pub async fn create
+    ( language_server : Rc<language_server::Connection>
+    , module_path     : Rc<controller::module::Path>
+    , root_definition : DefinitionName
+    ) -> FallibleResult<Self> {
+        let logger = Logger::new("ExecutionContext");
+        let model  = model::ExecutionContext::new(root_definition);
+        trace!(logger,"Creating Execution Context.");
+        let id = language_server.client.create_execution_context().await?.context_id;
+        trace!(logger,"Execution Context created. Id:{id}");
+        let this  = Self {id,module_path,model,language_server,logger};
+        this.push_root_frame().await?;
+        trace!(this.logger,"Pushed root frame");
+        Ok(this)
+    }
+
+    fn push_root_frame(&self) -> impl Future<Output=FallibleResult<()>> {
+        let method_pointer = language_server::MethodPointer {
+            file            : self.module_path.file_path().clone(),
+            defined_on_type : self.module_path.module_name().to_string(),
+            name            : self.model.entry_point.name.item.clone(),
+        };
+        let this_argument_expression         = default();
+        let positional_arguments_expressions = default();
+
+        let call = language_server::ExplicitCall {method_pointer,this_argument_expression,
+            positional_arguments_expressions};
+        let frame  = language_server::StackItem::ExplicitCall(call);
+        let result = self.language_server.push_to_execution_context(self.id,frame);
+        result.map(|res| res.map_err(|err| err.into()))
+    }
+
+    /// Push a new stack item to execution context.
+    pub fn push(&self, stack_item: LocalCall) -> impl Future<Output=Result<(),RpcError>> {
+        let expression_id = stack_item.call;
+        let call          = language_server::LocalCall{expression_id};
+        let frame         = language_server::StackItem::LocalCall(call);
+        self.model.push(stack_item);
+        self.language_server.push_to_execution_context(self.id,frame)
+    }
+
+    /// Pop the last stack item from this context. It returns error when only root call
+    /// remains.
+    pub async fn pop(&self) -> FallibleResult<()> {
+        self.model.pop()?;
+        self.language_server.pop_from_execution_context(self.id).await?;
+        Ok(())
+    }
+
+    /// Create a mock which does no call on `language_server` during construction.
+    #[cfg(test)]
+    pub fn new_mock
+    ( id              : model::execution_context::Id
+    , path            : controller::module::Path
+    , model           : model::ExecutionContext
+    , language_server : language_server::MockClient
+    ) -> Self {
+        let module_path     = Rc::new(path);
+        let language_server = language_server::Connection::new_mock_rc(language_server);
+        let logger          = Logger::new("ExecuctionContext mock");
+        ExecutionContext {id,model,module_path,language_server,logger}
+    }
+}
+
+impl Drop for ExecutionContext {
+    fn drop(&mut self) {
+        let id     = self.id;
+        let ls     = self.language_server.clone_ref();
+        let logger = self.logger.clone_ref();
+        executor::global::spawn(async move {
+            let result = ls.client.destroy_execution_context(id).await;
+            if result.is_err() {
+                error!(logger,"Error when destroying Execution Context: {result:?}.");
+            }
+        });
+    }
+}
+
+
+
+// =============
+// === Tests ===
+// =============
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use crate::executor::test_utils::TestWithLocalPoolExecutor;
+
+    use language_server::response;
+    use utils::test::ExpectTuple;
+
+
+
+    #[test]
+    fn creating_context() {
+        let path       = Rc::new(controller::module::Path::from_module_name("Test"));
+        let context_id = model::execution_context::Id::new_v4();
+        let root_def   = DefinitionName::new_plain("main");
+        let ls_client  = language_server::MockClient::default();
+        ls_client.set_create_execution_context_result(Ok(response::CreateExecutionContext {
+            context_id,
+            can_modify       : create_capability("executionContext/canModify",context_id),
+            receives_updates : create_capability("executionContext/receivesUpdates",context_id),
+        }));
+        let expected_method = language_server::MethodPointer {
+            file            : path.file_path().clone(),
+            defined_on_type : "Test".to_string(),
+            name            : "main".to_string(),
+        };
+        let expected_root_frame = language_server::ExplicitCall {
+            method_pointer                   : expected_method,
+            this_argument_expression         : None,
+            positional_arguments_expressions : vec![]
+        };
+        let expected_stack_item = language_server::StackItem::ExplicitCall(expected_root_frame);
+        ls_client.set_push_to_execution_context_result(context_id,expected_stack_item,Ok(()));
+        ls_client.set_destroy_execution_context_result(context_id,Ok(()));
+        ls_client.expect_all_calls();
+        let connection = language_server::Connection::new_mock_rc(ls_client);
+
+        let mut test = TestWithLocalPoolExecutor::set_up();
+        test.run_task(async move {
+            let context = ExecutionContext::create(connection,path.clone(),root_def).await.unwrap();
+            assert_eq!(context_id             , context.id);
+            assert_eq!(path                   , context.module_path);
+            assert_eq!(Vec::<LocalCall>::new(), context.model.stack_items().collect_vec());
+        })
+    }
+
+    fn create_capability
+    (method:impl Str, context_id:model::execution_context::Id)
+    -> language_server::CapabilityRegistration {
+        language_server::CapabilityRegistration {
+            method           : method.into(),
+            register_options : language_server::RegisterOptions::ExecutionContextId {context_id},
+        }
+    }
+
+    #[test]
+    fn pushing_stack_item() {
+        let id                  = model::execution_context::Id::new_v4();
+        let definition          = model::execution_context::DefinitionId::new_plain_name("foo");
+        let expression_id       = model::execution_context::ExpressionId::new_v4();
+        let path                = controller::module::Path::from_module_name("Test");
+        let root_def            = DefinitionName::new_plain("main");
+        let model               = model::ExecutionContext::new(root_def);
+        let ls                  = language_server::MockClient::default();
+        let expected_call_frame = language_server::LocalCall{expression_id};
+        let expected_stack_item = language_server::StackItem::LocalCall(expected_call_frame);
+        
+        ls.set_push_to_execution_context_result(id,expected_stack_item,Ok(()));
+        ls.set_destroy_execution_context_result(id,Ok(()));
+        let context  = ExecutionContext::new_mock(id,path.clone(),model,ls);
+
+        let mut test = TestWithLocalPoolExecutor::set_up();
+        test.run_task(async move {
+            let item = LocalCall {
+                call       : expression_id,
+                definition : definition.clone()
+            };
+            context.push(item.clone()).await.unwrap();
+            assert_eq!((item,), context.model.stack_items().expect_tuple());
+        })
+    }
+
+    #[test]
+    fn popping_stack_item() {
+        let id   = model::execution_context::Id::new_v4();
+        let item = LocalCall {
+            call       : model::execution_context::ExpressionId::new_v4(),
+            definition : model::execution_context::DefinitionId::new_plain_name("foo"),
+        };
+        let path          = controller::module::Path::from_module_name("Test");
+        let root_def      = DefinitionName::new_plain("main");
+        let ls            = language_server::MockClient::default();
+        let model         = model::ExecutionContext::new(root_def);
+        ls.set_pop_from_execution_context_result(id,Ok(()));
+        ls.set_destroy_execution_context_result(id,Ok(()));
+        model.push(item);
+        let context  = ExecutionContext::new_mock(id,path.clone(),model,ls);
+
+        let mut test = TestWithLocalPoolExecutor::set_up();
+        test.run_task(async move {
+            context.pop().await.unwrap();
+            assert_eq!(Vec::<LocalCall>::new(), context.model.stack_items().collect_vec());
+            // Pop on empty stack.
+            assert!(context.pop().await.is_err());
+        })
+    }
+}

gui/src/rust/ide/src/view/layout.rs

@@ -91,15 +91,15 @@ impl ViewLayout {
     ( logger           : &Logger
     , kb_actions       : &mut keyboard::Actions
     , application      : &Application
-    , text_controller  : controller::text::Handle
+    , text_controller  : controller::Text
-    , graph_controller : controller::graph::Handle
+    , graph_controller : controller::ExecutedGraph
     , fonts            : &mut FontRegistry
     ) -> Self {
         let logger        = logger.sub("ViewLayout");
         let world         = &application.display;
         let text_editor   = TextEditor::new(&logger,world,text_controller,kb_actions,fonts);
-        let node_editor   = NodeEditor::new(&logger,application,graph_controller.clone());
+        let node_editor   = NodeEditor::new(&logger,application,graph_controller.clone_ref());
-        let node_searcher = NodeSearcher::new(world,&logger,graph_controller,fonts);
+        let node_searcher = NodeSearcher::new(world,&logger,graph_controller.graph.clone_ref(),fonts);
         world.add_child(&text_editor.display_object());
         world.add_child(&node_editor);
         world.add_child(&node_searcher);

gui/src/rust/ide/src/view/node_editor.rs

@@ -27,7 +27,7 @@ use weak_table::weak_value_hash_map::Entry::{Occupied, Vacant};
 pub struct GraphEditorIntegration {
     pub logger     : Logger,
     pub editor     : GraphEditor,
-    pub controller : controller::Graph,
+    pub controller : controller::ExecutedGraph,
     id_to_node     : RefCell<WeakValueHashMap<ast::Id,WeakNode>>,
     node_to_id     : RefCell<WeakKeyHashMap<WeakNode,ast::Id>>,
 
@@ -35,7 +35,7 @@ pub struct GraphEditorIntegration {
 
 impl GraphEditorIntegration {
     /// Constructor. It creates GraphEditor panel and connect it with given controller handle.
-    pub fn new(logger:Logger, app:&Application, controller:controller::Graph) -> Rc<Self> {
+    pub fn new(logger:Logger, app:&Application, controller:controller::ExecutedGraph) -> Rc<Self> {
         let editor     = app.views.new::<GraphEditor>();
         let id_to_node = default();
         let node_to_id = default();
@@ -43,12 +43,15 @@ impl GraphEditorIntegration {
         Self::setup_controller_event_handling(&this);
         Self::setup_keyboard_event_handling(&this);
         Self::setup_mouse_event_handling(&this);
+        if let Err(err) = this.invalidate_graph() {
+            error!(this.logger,"Error while initializing graph display: {err}");
+        }
         this
     }
 
     /// Reloads whole displayed content to be up to date with module state.
     pub fn invalidate_graph(&self) -> FallibleResult<()> {
-        let nodes = self.controller.nodes()?;
+        let nodes = self.controller.graph.nodes()?;
         let ids   = nodes.iter().map(|node| node.info.id() ).collect();
         self.retain_ids(&ids);
         for (i,node_info) in nodes.iter().enumerate() {
@@ -71,7 +74,7 @@ impl GraphEditorIntegration {
     }
 
     fn setup_controller_event_handling(this:&Rc<Self>) {
-        let stream  = this.controller.subscribe();
+        let stream  = this.controller.graph.subscribe();
         let weak    = Rc::downgrade(this);
         let handler = process_stream_with_handle(stream,weak,move |notification,this| {
             let result = match notification {
@@ -97,7 +100,7 @@ impl GraphEditorIntegration {
                     this.editor.nodes.selected.for_each(|node_id| {
                         let id = this.node_to_id.borrow().get(&node_id.0).cloned(); // FIXME .0
                         if let Some(id) = id {
-                            if let Err(err) = this.controller.remove_node(id) {
+                            if let Err(err) = this.controller.graph.remove_node(id) {
                                 this.logger.error(|| format!("ERR: {:?}", err));
                             }
                         }
@@ -119,7 +122,7 @@ impl GraphEditorIntegration {
             if let Some((node_pos,this)) = node_pos.and_then(|n| this.map(|t| (n,t))) {
                 let id = this.node_to_id.borrow().get(&node_id.0).cloned(); // FIXME .0
                 if let Some(id) = id {
-                    this.controller.module.with_node_metadata(id, |md| {
+                    this.controller.graph.module.with_node_metadata(id, |md| {
                         md.position = Some(model::module::Position::new(node_pos.x, node_pos.y));
                     })
                 }
@@ -153,12 +156,12 @@ impl GraphEditorIntegration {
 pub struct NodeEditor {
     display_object : display::object::Instance,
     graph          : Rc<GraphEditorIntegration>,
-    controller     : controller::graph::Handle,
+    controller     : controller::ExecutedGraph,
 }
 
 impl NodeEditor {
     /// Create Node Editor Panel.
-    pub fn new(logger:&Logger, app:&Application, controller:controller::graph::Handle) -> Self {
+    pub fn new(logger:&Logger, app:&Application, controller:controller::ExecutedGraph) -> Self {
         let logger         = logger.sub("NodeEditor");
         let graph          = GraphEditorIntegration::new(logger,app,controller.clone_ref());
         let display_object = display::object::Instance::new(&graph.logger);

gui/src/rust/ide/src/view/project.rs

@@ -73,12 +73,13 @@ impl ProjectView {
     pub async fn new(logger:&Logger, controller:controller::Project)
     -> FallibleResult<Self> {
         let root_id              = controller.language_server_rpc.content_root();
-        let path                 = controller::module::Path::new(root_id,&INITIAL_FILE_PATH);
+        let path                 = controller::FilePath::new(root_id,&INITIAL_FILE_PATH);
         let text_controller      = controller.text_controller(path.clone()).await?;
         let main_name            = DefinitionName::new_plain(MAIN_DEFINITION_NAME);
         let graph_id             = controller::graph::Id::new_single_crumb(main_name);
-        let module_controller    = controller.module_controller(path).await?;
+        let module_controller    = controller.module_controller(path.try_into()?).await?;
-        let graph_controller     = module_controller.graph_controller_unchecked(graph_id);
+        let graph_controller     = module_controller.executed_graph_controller_unchecked(graph_id);
+        let graph_controller     = graph_controller.await?;
         let application          = Application::new(&web::get_html_element_by_id("root").unwrap());
         let _world               = &application.display;
         // graph::register_shapes(&world);
@@ -88,10 +89,10 @@ impl ProjectView {
         let mut keyboard_actions = keyboard::Actions::new(&keyboard);
         let resize_callback      = None;
         let mut fonts            = FontRegistry::new();
-        let layout               = ViewLayout::new
+        let layout               = ViewLayout::new(&logger,&mut keyboard_actions,&application,
-            (&logger,&mut keyboard_actions,&application,text_controller,graph_controller,&mut fonts);
+            text_controller,graph_controller,&mut fonts);
-        let data = ProjectViewData
+        let data = ProjectViewData {application,layout,resize_callback,controller,keyboard,
-            {application,layout,resize_callback,controller,keyboard,keyboard_bindings,keyboard_actions};
+            keyboard_bindings,keyboard_actions};
         Ok(Self::new_from_data(data).init())
     }
 

gui/src/rust/ide/tests/language_server.rs

@@ -101,10 +101,10 @@ async fn file_operations() {
     let explicit_call                    = ExplicitCall
         {method_pointer,positional_arguments_expressions,this_argument_expression};
     let stack_item = StackItem::ExplicitCall(explicit_call);
-    let response   = client.push_execution_context(execution_context_id,stack_item).await;
+    let response   = client.push_to_execution_context(execution_context_id,stack_item).await;
     response.expect("Couldn't push execution context.");
 
-    let response = client.pop_execution_context(execution_context_id).await;
+    let response = client.pop_from_execution_context(execution_context_id).await;
     response.expect("Couldn't pop execution context.");
 
     let visualisation_id     = uuid::Uuid::new_v4();