Add tentative scope-aware completion capability

Add the server capability and the required helper functions.
The proposed elements should be from within the designated
scope or (if no scope is selected) from the edited file.

The returned symbol should be declared before the cursor.

CHANGELOG.md

@@ -1,8 +1,12 @@
 # 0.3.0-dev
 
+## Added
+
+ - Added scope-aware completion.
+
 ## Changed
 
- - Full rework of the indexer
+ - Full rework of the indexer.
 
 # 0.2.1
 

indexer/include/index_scope.hpp

@@ -153,6 +153,13 @@ namespace diplomat::index
          */
         IndexSymbol* resolve_symbol(const std::string_view& path);
 
+        /**
+         * @brief Get the visible symbols object from the current scope.
+         * This represent all symbols declared here and all symbols declared in parents.
+         * @return std::vector<const IndexSymbol*> the set of found symbols.
+         */
+        std::vector<const IndexSymbol*> get_visible_symbols() const;
+
         /**
          * @brief Get the scope for position object
          * 

indexer/include/index_symbols.hpp

@@ -47,6 +47,7 @@ namespace diplomat::index
 		};
 
 		inline const std::optional<IndexRange>& get_source() const {return _source_range;};
+		inline const std::optional<IndexLocation> get_source_location() const {return _source_range ? _source_range->start : std::optional<IndexLocation>();};
 		inline const std::string& get_name() const {return _name;};
 		inline const std::unordered_set<IndexRange>& get_references() const {return _references_locations;};
 

indexer/index_scope.cpp

@@ -110,6 +110,24 @@ namespace diplomat::index {
 
 	}
 
+	std::vector<const IndexSymbol*> IndexScope::get_visible_symbols() const
+	{
+		const IndexScope* lu_scope = this;
+		std::vector<const IndexSymbol*> ret;
+		do {
+			for(auto& symb : std::views::values(lu_scope->_content))
+			{
+				ret.push_back(symb);
+			}
+
+			if(lu_scope->get_parent_access())
+				lu_scope = lu_scope->_parent;
+
+		} while (lu_scope->get_parent_access());
+
+		return ret;
+	}
+
 	IndexScope *IndexScope::get_scope_for_location(const IndexLocation &loc, bool deep)
 	{
 		if(deep)

lsp-server/diplomat/include/diplomat_lsp.hpp

@@ -43,9 +43,11 @@ class DiplomatLSP : public slsp::BaseLSP
 
         std::shared_ptr<DiplomatLSP> _this_shared;
 
+
         void _h_didChangeWorkspaceFolders(json params);
         void _h_didSaveTextDocument(json params);
         void _h_didOpenTextDocument(json params);
+        json _h_completion(slsp::types::CompletionParams params);
         json _h_formatting(json params);
         json _h_gotoDefinition(json params);
         json _h_references(json params);

lsp-server/diplomat/src/diplomat_lsp.cpp

@@ -86,12 +86,16 @@ _project_file_tree_valid(false)
     ServerCapabilities_workspace sc_ws;
     sc_ws.workspaceFolders = ws;
 
+    CompletionOptions sc_completion;
+    sc_completion.resolveProvider = false;
+
     capabilities.textDocumentSync = sync;
     capabilities.workspace = sc_ws;
     capabilities.definitionProvider = true;
     capabilities.referencesProvider = true;
     capabilities.documentFormattingProvider = true; // Can handle formatting options
     capabilities.renameProvider = true;
+    capabilities.completionProvider = sc_completion;
 
     _bind_methods();    
 }
@@ -165,6 +169,7 @@ void DiplomatLSP::_bind_methods()
 
     bind_notification("textDocument/didOpen", LSP_MEMBER_BIND(DiplomatLSP, _h_didOpenTextDocument));
     bind_notification("textDocument/didSave", LSP_MEMBER_BIND(DiplomatLSP, _h_didSaveTextDocument));
+    bind_request("textDocument/completion", LSP_MEMBER_BIND(DiplomatLSP, _h_completion));
     bind_request("textDocument/definition", LSP_MEMBER_BIND(DiplomatLSP, _h_gotoDefinition));
     bind_request("textDocument/formatting", LSP_MEMBER_BIND(DiplomatLSP, _h_formatting));
     bind_request("textDocument/references", LSP_MEMBER_BIND(DiplomatLSP, _h_references));

lsp-server/diplomat/src/diplomat_lsp_binds.cpp

@@ -77,7 +77,45 @@ void DiplomatLSP::_h_didOpenTextDocument(json _)
 {
 	DidOpenTextDocumentParams params =  _;
 	_save_client_uri(params.textDocument.uri);
-}   
+}
+
+json DiplomatLSP::_h_completion(slsp::types::CompletionParams params)
+{
+	CompletionList result;
+	result.isIncomplete = false;
+	_assert_index(true);
+
+	di::IndexLocation trigger_location = _lsp_to_index_location(params);
+	di::IndexScope* trigger_scope = _index->get_scope_by_position(trigger_location);
+
+	if(trigger_scope)
+	{
+		for(const di::IndexSymbol* symb : trigger_scope->get_visible_symbols() )
+		{
+			if(symb->get_source_location().value_or(trigger_location) > trigger_location)
+				continue;
+
+			CompletionItem record;
+			record.label = symb->get_name();
+			result.items.push_back(record);
+		}
+	}
+	else
+	{
+		// Propose symbols from the whole file.
+		for(const auto& symb : _index->get_file(trigger_location.file)->get_symbols() )
+		{
+			if(symb->get_source_location().value_or(trigger_location) > trigger_location)
+				continue;
+
+			CompletionItem record;
+			record.label = symb->get_name();
+			result.items.push_back(record);
+		}
+	}
+
+	return result;
+}
 
 json DiplomatLSP::_h_formatting(json _)
 {