Co-authored-by: Michael <[email protected]>

Author: ghaith

src/index.rs

@@ -26,6 +26,7 @@ pub mod symbol;
 #[cfg(test)]
 mod tests;
 pub mod visitor;
+pub mod scoped_index;
 
 /// A label represents a possible jump point in the source.
 /// It can be referenced by jump elements in the same unit
@@ -734,7 +735,7 @@ impl PouIndexEntry {
 /// the TypeIndex carries all types.
 /// it is extracted into its seaprate struct so it can be
 /// internally borrowed individually from the other maps
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct TypeIndex {
     /// all types (structs, enums, type, POUs, etc.)
     types: SymbolMap<String, DataType>,

src/index/scoped_index.rs

@@ -0,0 +1,57 @@
+use std::{collections::HashMap, rc::Rc};
+
+use plc_source::source_location::SourceLocation;
+
+use crate::typesystem::DataType;
+
+use super::VariableIndexEntry;
+
+/// A minimal index implementation that can be used for local scopes
+#[derive(Debug, Clone)]
+pub struct ScopedIndex {
+    ///The scope of the current index, this is usually a POU
+    scope: String,
+
+    /// A unique identifier that new variables in this scope will inherit
+    scope_suffix: usize,
+
+    /// The location that caused this scope to be created
+    start_location: SourceLocation,
+
+    /// New variables defined by this index
+    variables: HashMap<String, VariableIndexEntry>,
+
+    /// Datatypes defined by this index
+    type_index: HashMap<String, DataType>,
+
+    parent : Option<Rc<ScopedIndex>>
+
+}
+
+impl ScopedIndex {
+    pub fn merge_into(self, target: &mut Self) {
+        target.variables.extend(self.variables);
+        target.type_index.extend(self.type_index);
+    }
+
+    pub fn add_variable(&mut self, name: &str) {
+
+    }
+
+    pub fn add_type(&mut self, name: &str) {
+
+    }
+
+    pub fn find_variable(&self, name: &str) -> Option<&VariableIndexEntry> {
+        todo!()
+    }
+
+    pub fn find_type(&self, name: &str) -> Option<&DataType> {
+        todo!()
+    }
+
+    pub fn new(parent: Option<Rc<ScopedIndex>>, location: SourceLocation, scope: &str, suffix: usize) -> ScopedIndex {
+        ScopedIndex { scope: scope.to_string(), scope_suffix: suffix, start_location: location, parent, type_index: Default::default(), variables: Default::default() }
+    }
+
+}

src/index/symbol.rs

@@ -18,6 +18,18 @@ impl<K, V> Default for SymbolMap<K, V> {
     }
 }
 
+impl<K, V> Clone for SymbolMap<K, V>
+where
+    K: Clone,
+    V: Clone,
+{
+    fn clone(&self) -> Self {
+        Self {
+            inner_map: self.inner_map.clone()
+        }
+    }
+}
+
 impl<K, V> SymbolMap<K, V>
 where
     K: Hash + Eq,