Implemented more robust LSP diagnostics and better parsing logic

docs/CODE_DOCUMENTATION.md

@@ -43,7 +43,7 @@ The brain of the system. It maintains a holistic view of the project.
 *   **ProjectTree**: The central data structure. It holds the root of the configuration hierarchy (`Root`), references, and isolated files.
 *   **ProjectNode**: Represents a logical node in the configuration. Since a node can be defined across multiple files (fragments), `ProjectNode` aggregates these fragments. It also stores locally defined variables in its `Variables` map.
 *   **NodeMap**: A hash map index (`map[string][]*ProjectNode`) for $O(1)$ symbol lookups, optimizing `FindNode` operations.
-*   **Reference Resolution**: The `ResolveReferences` method links `Reference` objects to their target `ProjectNode` or `VariableDefinition`. It uses `resolveScopedName` to respect lexical scoping rules, searching up the hierarchy from the reference's container.
+*   **Reference Resolution**: The `ResolveReferences` method links `Reference` objects to their target `ProjectNode` or `VariableDefinition`. It uses `ResolveName` (exported) which respects lexical scoping rules by searching the hierarchy upwards from the reference's container, using `FindNode` for deep searches within each scope.
 
 ### 3. `internal/validator`
 
@@ -100,12 +100,13 @@ Manages CUE schemas.
 5.  Diagnostics are printed (CLI) or published via `textDocument/publishDiagnostics` (LSP).
 
 ### Threading Check Logic
-1.  Finds the `RealTimeApplication` node.
-2.  Iterates through `States` and `Threads`.
-3.  For each Thread, resolves the `Functions` (GAMs).
-4.  For each GAM, resolves connected `DataSources` via Input/Output signals.
-5.  Maps `DataSource -> Thread` within the context of a State.
-6.  If a DataSource is seen in >1 Thread, it checks the `#meta.multithreaded` property. If false (default), an error is raised.
+1.  Iterates all `RealTimeApplication` nodes found in the project.
+2.  For each App:
+    1.  Finds `States` and `Threads`.
+    2.  For each Thread, resolves the `Functions` (GAMs).
+    3.  For each GAM, resolves connected `DataSources` via Input/Output signals.
+    4.  Maps `DataSource -> Thread` within the context of a State.
+    5.  If a DataSource is seen in >1 Thread, it checks the `#meta.multithreaded` property. If false (default), an error is raised.
 
 ### INOUT Ordering Logic
 1.  Iterates Threads.

docs/CONFIGURATION_GUIDE.md

@@ -173,9 +173,11 @@ You can define variables using `#var`. The type expression supports CUE syntax.
 ```
 
 ### Usage
-Reference a variable using `@`:
+Reference a variable using `$` (preferred) or `@`:
 
 ```marte
+Field = $MyVar
+// or
 Field = @MyVar
 ```
 
@@ -187,7 +189,7 @@ You can use operators in field values. Supported operators:
 ```marte
 Field1 = 10 + 20 * 2  // 50
 Field2 = "Hello " .. "World"
-Field3 = @MyVar + 5
+Field3 = $MyVar + 5
 ```
 
 ### Build Override
@@ -197,3 +199,21 @@ You can override variable values during build:
 mdt build -vMyVar=200 -vEnv="PROD" src/*.marte
 ```
 
+## 7. Validation Rules (Detail)
+
+### Data Flow Validation
+`mdt` checks for logical data flow errors:
+- **Consumed before Produced**: If a GAM reads an INOUT signal that hasn't been written by a previous GAM in the same cycle, an error is reported.
+- **Produced but not Consumed**: If a GAM writes an INOUT signal that is never read by subsequent GAMs, a warning is reported.
+- **Initialization**: Providing a `Value` field in an `InputSignal` treats it as "produced" (initialized), resolving "Consumed before Produced" errors.
+
+### Threading Rules
+A DataSource that is **not** marked as multithreaded (default) cannot be used by GAMs running in different threads within the same State.
+
+To allow sharing, the DataSource class in the schema must have `#meta: multithreaded: true`.
+
+### Implicit vs Explicit Signals
+- **Explicit**: Signal defined in `DataSource.Signals`.
+- **Implicit**: Signal used in GAM but not defined in DataSource. `mdt` reports a warning unless suppressed.
+
+

docs/EDITOR_INTEGRATION.md

@@ -2,11 +2,12 @@
 
 `mdt` includes a Language Server Protocol (LSP) implementation that provides features like:
 
-- Syntax highlighting and error reporting
+- Syntax highlighting and error reporting (Parser & Semantic)
 - Auto-completion
 - Go to Definition / References
 - Hover documentation
 - Symbol renaming
+- Incremental synchronization (Robust)
 
 The LSP server is started via the command: