formatter: add DATA_BLOCK to BLOCKS + DECLARATIONS

Without this, DATA_BLOCK wasn't recognized as a declaration block,
so the stack was never populated for DB files. END_DATA_BLOCK fell
through to regular-line handling and got a tab prefix (from body
get_indent()), while DATA_BLOCK itself was flush-left.

Added DATA_BLOCK to both BLOCKS (ender = END_DATA_BLOCK) and
DECLARATIONS so it gets the same treatment as FUNCTION_BLOCK:
stack cleared, no_indent=true, and END_DATA_BLOCK handled by the
declaration ender path (flush-left output).

AGENTS.md

@@ -24,7 +24,7 @@ lua test/test_formatter.lua  # Run formatter tests
 lua test/test_plc_json.lua   # Run plc_json tests
 
 # Reference Project
-# Tests use files from: ~/dev/siemens/projects/scl_lang_support_lazyvim_ref_project/
+# Tests use files from: ~/Documents/siemens/scl_lang_support_lazyvim_ref_project/
 # Override with: SCL_REF_PROJECT=/path/to/ref lua tests/run_tests.lua
 ```
 
@@ -152,7 +152,7 @@ The LSP validates data types and provides warnings for unknown types:
 
 Use the reference project for testing:
 ```
-~/dev/siemens/projects/scl_lang_support_lazyvim_ref_project/
+~/Documenta/siemens/scl_lang_support_lazyvim_ref_project/
 ```
 
 Contains `.scl`, `.db`, `.udt`, and `.xml` files for comprehensive testing of:

README.md

@@ -58,14 +58,25 @@ make test
 # or: lua src/main.lua --test
 ```
 
-### Mason Installation (Neovim)
+### Neovim + Mason (Recommended)
 
-For Neovim users, install via [mason.nvim](https://github.com/mason-org/mason.nvim) using a custom registry. See the [`tia-lsp.nvim` README](https://gitea.l-tech.rs/lazar/tia-lsp.nvim) for full setup instructions.
+The recommended way is via [mason.nvim](https://github.com/mason-org/mason.nvim) using the
+[`tia-mason-registry`](https://gitea.l-tech.rs/lazar/tia-mason-registry). See the
+[`tia-lsp.nvim` README](https://gitea.l-tech.rs/lazar/tia-lsp.nvim) for full step-by-step instructions.
 
-Quick summary:
+### Manual Setup
-1. Add the `tia-mason-registry` as a lazy.nvim plugin
+
-2. Register it with mason: `registries = { "file:~/.local/share/nvim/lazy/tia-mason-registry", "github:mason-org/mason-registry" }`
+```bash
-3. `:MasonInstall tia-lsp`
+# 1. Clone this repository
+git clone --depth 1 https://gitea.l-tech.rs/lazar/tia-lsp.git ~/tia-lsp
+
+# 2. Compile the tree-sitter parser
+cc -fPIC -I ~/tia-lsp/src/tree_sitter -c ~/tia-lsp/src/parser.c -o ~/tia-lsp/parser.o
+cc -shared ~/tia-lsp/parser.o -o ~/tia-lsp/parser.so
+
+# 3. Start the server (or configure your editor to run this)
+lua ~/tia-lsp/src/main.lua
+```
 
 ## External UDT Support
 

src/diagnostics.lua

@@ -106,6 +106,12 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
       ExternalWRITABLE = true,  -- case variant
       ExternalVISIBLE = true,
       ExternalACCESSIBLE = true,
+      EXTERNALWRITABLE = true,  -- all-caps VCI export variant
+      EXTERNALVISIBLE = true,   -- all-caps VCI export variant
+      EXTERNALACCESSIBLE = true,-- all-caps VCI export variant
+      InstructionName = true,
+      LibVersion = true,
+      LibName = true,
       S7_SetPoint = true,
       S7_Optimized_Access = true,
     }
@@ -132,27 +138,37 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
       return prefix == "T" or prefix == "D" or prefix == "S"
     end
 
-    if not in_var_section then
+    -- Check if hash is part of a base-specific number literal like 16#FFFF, 2#1010
-      local hash_vars = {}
+    local function is_number_literal_at(line, match_start)
-      for var in line:gmatch("#[%w_]+") do
+      if not line or not match_start then return false end
-        local var_name = var:sub(2)
+      if match_start <= 1 then return false end
-        local match_start = line:find(var, 1, true)
+      local before = line:sub(match_start - 1, match_start - 1)
-        if not is_iec_literal_at(line, match_start) then
+      return before:match("%d") ~= nil
-          hash_vars[var_name] = true
+    end
-        end
-      end
 
-      for var_name, _ in pairs(hash_vars) do
+    if not in_var_section then
-        if not variables[var_name] and not all_types[var_name] then
+      if not (trimmed:match("^%s*//") or trimmed:match("^%s*%(%*")) then
-          local var_start = line:find("#" .. var_name, 1, true)
+        local hash_vars = {}
-          if var_start then
+        for var in line:gmatch("#[%w_]+") do
-            table.insert(diagnostics, {
+          local var_name = var:sub(2)
-              range = range_to_lsp(line_num, var_start - 1, line_num, var_start + #var_name - 1),
+          local match_start = line:find(var, 1, true)
-              severity = DiagnosticSeverity.Error,
+          if not is_iec_literal_at(line, match_start) and not is_number_literal_at(line, match_start) then
-              message = string.format("Undefined variable: %s", var_name),
+            hash_vars[var_name] = true
-              code = "SCL001",
+          end
-              source = "tia_lsp",
+        end
-            })
+
+        for var_name, _ in pairs(hash_vars) do
+          if not variables[var_name] and not all_types[var_name] then
+            local var_start = line:find("#" .. var_name, 1, true)
+            if var_start then
+              table.insert(diagnostics, {
+                range = range_to_lsp(line_num, var_start - 1, line_num, var_start + #var_name - 1),
+                severity = DiagnosticSeverity.Error,
+                message = string.format("Undefined variable: %s", var_name),
+                code = "SCL001",
+                source = "tia_lsp",
+              })
+            end
           end
         end
       end
@@ -215,8 +231,13 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
           if type_part:match("%s+OF%s+") then
             base_type = type_part:match('.*%s+OF%s+"([^"]+)"') or type_part:match(".*%s+OF%s+([%w_]+)")
           end
+
+          local is_array_keyword = base_type and base_type:upper() == "ARRAY"
+              and type_part:match("^[Aa][Rr][Rr][Aa][Yy]%[")
+
           local upper_type = base_type and base_type:upper() or nil
           if base_type and base_type ~= "" and
+             not is_array_keyword and
              not all_types[base_type] and
              not builtin.is_known_data_type(upper_type) and
              not builtin.is_known_type_or_instruction(upper_type) then
@@ -235,6 +256,26 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
     if trimmed:match("^%s*//") or trimmed:match("^%s*%(%*") then
       -- Skip comments
     else
+      -- Check for unassigned parameters in FB/FC calls
+      for unassigned in line:gmatch("([%w_]+)%s*:=%s*[,%)]") do
+        table.insert(diagnostics, {
+          range = range_to_lsp(line_num, line:find(unassigned, 1, true) - 1, line_num, line:find(unassigned, 1, true) + #unassigned),
+          severity = DiagnosticSeverity.Warning,
+          message = string.format("Unassigned input parameter: %s :=", unassigned),
+          code = "SCL006",
+          source = "tia_lsp",
+        })
+      end
+      for unassigned in line:gmatch("([%w_]+)%s*=>%s*[,%)]") do
+        table.insert(diagnostics, {
+          range = range_to_lsp(line_num, line:find(unassigned, 1, true) - 1, line_num, line:find(unassigned, 1, true) + #unassigned),
+          severity = DiagnosticSeverity.Warning,
+          message = string.format("Unassigned output parameter: %s =>", unassigned),
+          code = "SCL006",
+          source = "tia_lsp",
+        })
+      end
+
       for assignment in line:gmatch("#[%w_]+%s*:=") do
         local var_name = assignment:match("#([%w_]+)")
         if var_name and in_var_section then

src/formatter.lua

@@ -43,6 +43,7 @@ local BLOCKS = {
   ["FUNCTION"] = "END_FUNCTION",
   ["FUNCTION_BLOCK"] = "END_FUNCTION_BLOCK",
   ["ORGANIZATION_BLOCK"] = "END_ORGANIZATION_BLOCK",
+  ["DATA_BLOCK"] = "END_DATA_BLOCK",
   ["TYPE"] = "END_TYPE",
   ["STRUCT"] = "END_STRUCT",
   ["VAR"] = "END_VAR",
@@ -72,7 +73,6 @@ local NEEDS_SEMICOLON = {
   ["END_WHILE"] = true,
   ["END_REPEAT"] = true,
   ["END_CASE"] = true,
-  ["END_REGION"] = true,
 }
 
 local VAR_KEYWORDS = {
@@ -92,6 +92,7 @@ local DECLARATIONS = {
   ["FUNCTION"] = true,
   ["FUNCTION_BLOCK"] = true,
   ["ORGANIZATION_BLOCK"] = true,
+  ["DATA_BLOCK"] = true,
   ["TYPE"] = true,
   ["STRUCT"] = true,
 }
@@ -111,9 +112,6 @@ local CONTINUATION_OPERATORS = {
 --- @return table Array of TextEdit objects with range and newText
 function M.format_document(content, options)
   options = options or {}
-  local use_spaces = options.insertSpaces or false
-  local indent_size = options.tabSize or 1
-  local indent_char = use_spaces and string.rep(" ", indent_size) or "\t"
 
   local collapse_attributes = options.collapseAttributes
   if collapse_attributes == nil then
@@ -127,6 +125,11 @@ function M.format_document(content, options)
     end
   end
 
+  local bom = string.char(239, 187, 191)
+  if content:sub(1, 3) == bom then
+    content = content:sub(4)
+  end
+
   local lines = {}
   for line in content:gmatch("([^\n]*)\n") do
     table.insert(lines, line)
@@ -141,15 +144,29 @@ function M.format_document(content, options)
 
   local stack = {}
   local formatted_lines = {}
+  local in_code_body = false
+  local in_var_block = false
 
   local function get_indent()
-    local level = 0
+    if in_code_body then
-    for _, block in ipairs(stack) do
+      local level = 0
-      if not block.no_indent then
+      for _, block in ipairs(stack) do
-        level = level + 1
+        if not block.no_indent then
+          level = level + 1
+        end
+      end
+      return "\t" .. string.rep("    ", level)
+    else
+      if in_var_block then
+        return "  "
+      else
+        return ""
       end
     end
-    return string.rep(indent_char, level)
+  end
+
+  local function get_code_indent(level)
+    return "\t" .. string.rep("    ", level)
   end
 
   local function is_assignment_continuation(trimmed)
@@ -261,6 +278,15 @@ function M.format_document(content, options)
       table.insert(params, last_param)
     end
     
+    -- Remove unassigned parameters (e.g. "IN :=", "Q =>", "ET =>")
+    local filtered = {}
+    for _, p in ipairs(params) do
+      if not p:match("^[%w_]+%s*:=%s*$") and not p:match("^[%w_]+%s*=>%s*$") then
+        table.insert(filtered, p)
+      end
+    end
+    params = filtered
+    
     if #params == 0 then
       return { base_indent .. fb_name .. "();" }
     end
@@ -276,7 +302,7 @@ function M.format_document(content, options)
   end
 
   local function is_case_label(trimmed)
-    return trimmed:match("^[%w_#]+%s*:%s*$") ~= nil
+    return     trimmed:match("^\"[^\"]+\"%s*:%s*$") ~= nil or trimmed:match("^[%w_#]+%s*:%s*$") ~= nil
   end
 
   local function extract_variable_name(line)
@@ -489,7 +515,7 @@ function M.format_document(content, options)
     if DECLARATIONS[kw] then
       stack = {}
       table.insert(formatted_lines, trimmed)
-      table.insert(stack, { type = kw, indent = 0, is_declaration = true })
+      table.insert(stack, { type = kw, indent = 0, is_declaration = true, no_indent = true })
       goto continue
     end
 
@@ -507,25 +533,38 @@ function M.format_document(content, options)
       while #stack > 0 and VAR_KEYWORDS[stack[#stack].type] do
         table.remove(stack)
       end
-      table.insert(formatted_lines, get_indent() .. trimmed)
+      in_var_block = false
+      in_code_body = true
+      table.insert(formatted_lines, trimmed)
       goto continue
     end
 
-    if VAR_KEYWORDS[kw] then
+    if in_code_body then
-      while #stack > 0 and not stack[#stack].is_declaration do
+      if VAR_KEYWORDS[kw] then
-        table.remove(stack)
+        table.insert(formatted_lines, get_indent() .. trimmed)
+        table.insert(stack, { type = kw, indent = #stack, is_var = true })
+        goto continue
       end
-      table.insert(formatted_lines, get_indent() .. trimmed)
-      table.insert(stack, { type = kw, indent = #stack, is_var = true })
-      goto continue
-    end
 
-    if kw == "END_VAR" then
+      if kw == "END_VAR" then
-      while #stack > 0 and VAR_KEYWORDS[stack[#stack].type] do
+        while #stack > 0 and VAR_KEYWORDS[stack[#stack].type] do
-        table.remove(stack)
+          table.remove(stack)
+        end
+        table.insert(formatted_lines, get_indent() .. trimmed)
+        goto continue
+      end
+    else
+      if VAR_KEYWORDS[kw] then
+        in_var_block = true
+        table.insert(formatted_lines, trimmed)
+        goto continue
+      end
+
+      if kw == "END_VAR" then
+        in_var_block = false
+        table.insert(formatted_lines, trimmed)
+        goto continue
       end
-      table.insert(formatted_lines, get_indent() .. trimmed)
-      goto continue
     end
 
     if kw and BLOCKS[kw] == nil then
@@ -556,7 +595,7 @@ function M.format_document(content, options)
               break
             end
           end
-          then_indent = if_block and string.rep(indent_char, if_block.indent) or get_indent()
+          then_indent = if_block and get_code_indent(if_block.indent) or get_indent()
         end
         table.insert(formatted_lines, then_indent .. trimmed)
         table.insert(stack, { type = "THEN_CONTENT", indent = #stack, no_indent = true })
@@ -573,7 +612,7 @@ function M.format_document(content, options)
           end
         end
         if if_block then
-          formatted = string.rep(indent_char, if_block.indent) .. trimmed
+          formatted = get_code_indent(if_block.indent) .. trimmed
         else
           formatted = get_indent() .. trimmed
         end
@@ -582,7 +621,7 @@ function M.format_document(content, options)
         -- Check if this is a multi-line condition (doesn't end with THEN on same line)
         if not trimmed:match("THEN%s*$") then
           in_condition = true
-          condition_indent = string.rep(indent_char, (if_block and if_block.indent or 0) + 1)
+          condition_indent = get_code_indent((if_block and if_block.indent or 0) + 1)
         end
       else
         formatted = get_indent() .. trimmed
@@ -597,9 +636,10 @@ function M.format_document(content, options)
         while #stack > case_idx do
           table.remove(stack)
         end
-        local label_indent = string.rep(indent_char, case_block.indent + 1)
+        local label_indent = get_code_indent(case_block.indent + 1)
         table.insert(formatted_lines, label_indent .. trimmed)
         table.insert(stack, { type = "CASE_LABEL", indent = case_block.indent + 1, no_indent = true })
+        table.insert(stack, { type = "CASE_CONTENT", indent = case_block.indent + 2 })
       else
         table.insert(formatted_lines, get_indent() .. trimmed)
       end
@@ -613,7 +653,7 @@ function M.format_document(content, options)
           current_level = current_level + 1
         end
       end
-      local formatted = string.rep(indent_char, current_level) .. trimmed
+      local formatted = get_code_indent(current_level) .. trimmed
       table.insert(formatted_lines, formatted)
       table.insert(stack, { type = kw, indent = current_level })
       if kw == "IF" or kw == "ELSIF" then
@@ -621,33 +661,24 @@ function M.format_document(content, options)
         if not trimmed:match("THEN%s*$") then
           in_condition = true
           -- Continuation lines should be indented one level deeper than IF/ELSIF
-          condition_indent = string.rep(indent_char, current_level + 1)
+          condition_indent = get_code_indent(current_level + 1)
         end
       end
       goto continue
     end
 
     -- Regular line - check for assignment start
-    -- But not if its inside an attribute block, exiting one, or a single-line attribute block
+    if in_code_body and not in_attr_block and not exiting_attr_block and trimmed:match(":=") and not trimmed:match("^{.*}$") then
-    if not in_attr_block and not exiting_attr_block and trimmed:match(":=") and not trimmed:match("^{.*}$") then
+      if trimmed:match(";%s*$") then
-      local base_indent = get_indent()
+        in_assignment = false
-      local assign_pos = trimmed:find(":=")
+      else
-      if assign_pos then
+        in_assignment = true
-        local var_part = trimmed:sub(1, assign_pos - 1)
+        assignment_continuation_indent = get_indent()
-        local var_trimmed = var_part:match("^(.-)%s*$")
-        assignment_continuation_indent = base_indent .. string.rep(" ", #var_trimmed + 4)
-        
-        if trimmed:match(";%s*$") then
-          in_assignment = false
-        else
-          in_assignment = true
-        end
       end
     else
       in_assignment = false
     end
     
-    -- Also reset assignment state when in attribute block
     if in_attr_block then
       in_assignment = false
     end

src/main.lua

@@ -71,6 +71,9 @@ local capabilities = {
 	workspaceSymbolProvider = true,
 	documentFormattingProvider = true,
 	documentRangeFormattingProvider = false,
+	executeCommandProvider = {
+		commands = { "SCLRescanWorkspaceTypes" },
+	},
 }
 
 local function uri_to_path(uri)
@@ -717,6 +720,72 @@ function handlers.textDocument_hover(params)
 	return nil
 end
 
+--- Detect if cursor is inside a function call's parentheses
+--- Scans backwards from cursor to find an unmatched ( and returns the name before it
+--- @param line string The current line content
+--- @param col number Cursor column (0-indexed LSP position)
+--- @return string|nil Function/block name, or nil if not in a call context
+local function get_call_context(line, col)
+	if col <= 1 then return nil end
+	local before_cursor = line:sub(1, col)
+	local paren_pos = nil
+	for i = #before_cursor, 1, -1 do
+		local c = before_cursor:sub(i, i)
+		if c == ")" then break end
+		if c == "(" then paren_pos = i; break end
+	end
+	if not paren_pos then return nil end
+	local before_paren = before_cursor:sub(1, paren_pos - 1)
+	return before_paren:match("([%w_]+)%s*$")
+end
+
+--- Resolve a function/variable call name to its parameter info
+--- Checks variables (for data_type resolution), built-in parameters, and workspace types
+--- @param call_name string The name to resolve (e.g., "instTestTimer" or "TON")
+--- @param variables table|nil Document variables table
+--- @param types table|nil Document types table
+--- @return table|nil Parameter definition with inputs and outputs arrays, or nil
+local function resolve_call_params(call_name, variables, types)
+	if not call_name then return nil end
+	local clean_name = call_name:gsub("^#", "")
+	local data_type = variables and variables[clean_name] and variables[clean_name].data_type
+	local resolved_name = data_type or clean_name
+	local builtin_params = builtin.get_parameters(resolved_name)
+	if builtin_params then return builtin_params end
+	local type_info = types and types[resolved_name]
+	if type_info and type_info.fields then
+		return { inputs = type_info.fields, outputs = {} }
+	end
+	return nil
+end
+
+local function add_param_items(items, params, prefix_filter)
+	for _, inp in ipairs(params.inputs or {}) do
+		local label = inp.name .. " := "
+		if prefix_filter == "" or inp.name:upper():sub(1, #prefix_filter) == prefix_filter:upper() then
+			table.insert(items, {
+				label = label,
+				kind = 13,
+				detail = "Parameter (" .. (inp.type or "ANY") .. ")",
+				insertText = inp.name .. " := ",
+				insertTextFormat = 1,
+			})
+		end
+	end
+	for _, out in ipairs(params.outputs or {}) do
+		local label = out.name .. " => "
+		if prefix_filter == "" or out.name:upper():sub(1, #prefix_filter) == prefix_filter:upper() then
+			table.insert(items, {
+				label = label,
+				kind = 13,
+				detail = "Output (" .. (out.type or "ANY") .. ")",
+				insertText = out.name .. " => ",
+				insertTextFormat = 1,
+			})
+		end
+	end
+end
+
 --- Handle textDocument/completion request
 --- Provides completion items based on context (VAR section, member access, etc.)
 --- @param params table Contains textDocument with uri and position
@@ -738,24 +807,28 @@ function handlers.textDocument_completion(params)
 	if line_idx <= #lines then
 		local line = lines[line_idx]
 		local col = params.position.character
-		local trigger = col > 0 and line:sub(col, col) or ""
+		local trigger = (params.context and params.context.triggerCharacter) or (col > 0 and line:sub(col, col) or "")
 		local line_before = col > 1 and line:sub(1, col - 1) or ""
 
 		-- Get word prefix being typed (for filtering)
-		local prefix_start = col - 1
+		-- Start from col (not col-1) so delimiters like ( stop the scan
+		local prefix_start = col
 		while prefix_start > 0 and line:sub(prefix_start, prefix_start):match("[%w_]") do
 			prefix_start = prefix_start - 1
 		end
-		local word_prefix = line:sub(prefix_start + 1, col - 1)
+		local word_prefix = col > prefix_start and line:sub(prefix_start + 1, col) or ""
 
-		-- Check if we're in VAR section
+		-- Check if typing after # prefix (e.g., #myVar)
+		local has_hash_prefix = line_before:match("#[%w_]*$")
+
+		-- Check if we're in VAR section (detects all VAR variants)
 		local in_var_section = false
 		for i = line_idx - 1, 1, -1 do
 			local prev_line = lines[i]:gsub("^%s+", ""):gsub("%s+$", "")
-			if prev_line:match("^END_VAR") or prev_line:match("^VAR_TEMP") or prev_line:match("^VAR_IN_OUT") or prev_line:match("^VAR_OUTPUT") or prev_line:match("^VAR_INPUT") then
+			if prev_line:match("^END_VAR") then
 				break
 			end
-			if prev_line:match("^VAR%s*$") or prev_line:match("^VAR$") then
+			if prev_line:match("^VAR") then
 				in_var_section = true
 				break
 			end
@@ -764,21 +837,29 @@ function handlers.textDocument_completion(params)
 		if trigger == "#" then
 			if doc.variables then
 				for name, info in pairs(doc.variables) do
-					table.insert(items, {
+					if word_prefix == "" or name:upper():sub(1, #word_prefix) == word_prefix:upper() then
-						label = "#" .. name,
+						table.insert(items, {
-						kind = 13,
+							label = "#" .. name,
-						detail = "Local variable (" .. (info.type or "unknown") .. ")",
+							filterText = "#" .. name,
-						insertText = "#" .. name,
+							kind = 13,
-						insertTextFormat = 1,
+							detail = "Variable (" .. (info.type or "VAR") .. "): " .. (info.data_type or "unknown"),
-					})
+							insertText = "#" .. name,
+							insertTextFormat = 1,
+						})
+					end
 				end
 			end
 		elseif trigger == "." then
-			local prefix_start = col - 1
+			local scan_end = col
+			local c = col > 0 and line:sub(col, col) or ""
+			if c == "" or c == "." then
+				scan_end = col - 1
+			end
+			local prefix_start = scan_end
 			while prefix_start > 0 and line:sub(prefix_start, prefix_start):match("[%w_]") do
 				prefix_start = prefix_start - 1
 			end
-			local prefix = line:sub(prefix_start + 1, col - 1)
+			local prefix = scan_end > prefix_start and line:sub(prefix_start + 1, scan_end) or ""
 
 			if prefix ~= "" then
 				local var_name = prefix:gsub("^#", "")
@@ -837,18 +918,45 @@ function handlers.textDocument_completion(params)
 				end
 			end
 		elseif trigger == "(" then
-			if doc.functions then
+			-- Try get_call_context first (handles case where ( is already in the line)
-				for _, func in ipairs(doc.functions) do
+			local call_name = get_call_context(line, col)
+			-- Fallback: ( may not be in the line yet (client sends completion before didChange)
+			if not call_name and col > 0 then
+				call_name = line:sub(1, col):match("([%w_]+)%s*$")
+			end
+			local params = call_name and resolve_call_params(call_name, doc.variables, doc.types)
+			if params then
+				add_param_items(items, params, "")
+			end
+
+			-- Also add variables and builtins so completion popup stays rich
+			-- even if auto-close ( or client-side filtering interferes
+			if doc.variables then
+				for name, info in pairs(doc.variables) do
 					table.insert(items, {
-						label = func.name,
+						label = "#" .. name,
-						kind = 3,
+						filterText = "#" .. name,
-						detail = func.kind:upper(),
+						kind = 13,
-						insertText = func.name .. "()",
+						detail = "Variable (" .. (info.type or "VAR") .. "): " .. (info.data_type or "unknown"),
-						insertTextFormat = 2,
+						insertText = "#" .. name,
+						insertTextFormat = 1,
 					})
 				end
 			end
+			for type_name, _ in pairs(builtin.DATA_TYPES) do
+				table.insert(items, { label = type_name, kind = 7, detail = "Data type", insertText = type_name, insertTextFormat = 1 })
+			end
+			for fb_name, _ in pairs(builtin.FUNCTION_BLOCKS) do
+				table.insert(items, { label = fb_name, kind = 6, detail = "Function block", insertText = fb_name, insertTextFormat = 1 })
+			end
+			for func_name, _ in pairs(builtin.FUNCTIONS) do
+				table.insert(items, { label = func_name, kind = 3, detail = "Function", insertText = func_name, insertTextFormat = 1 })
+			end
 		else
+			-- Check if we're inside a function call (e.g., after instTestTimer()
+			local call_name = get_call_context(line, col)
+			local call_params = call_name and resolve_call_params(call_name, doc.variables, doc.types)
+
 			-- Check context before cursor
 			local is_var_decl = line_before:match(":%s*$")
 
@@ -881,6 +989,27 @@ function handlers.textDocument_completion(params)
 						add_item(type_name, 7, type_info.kind or "Type")
 					end
 				end
+
+				-- Add declared variables (label without # so client-side matching works)
+				if doc.variables then
+					for name, info in pairs(doc.variables) do
+						if word_prefix == "" or name:upper():sub(1, #word_prefix) == word_prefix:upper() then
+							table.insert(items, {
+								label = name,
+								filterText = name,
+								kind = 13,
+								detail = "Variable (" .. (info.type or "VAR") .. "): " .. (info.data_type or "unknown"),
+								insertText = "#" .. name,
+								insertTextFormat = 1,
+							})
+						end
+					end
+				end
+
+				-- Add function/block call parameters if inside (...) context
+				if call_params then
+					add_param_items(items, call_params, word_prefix)
+				end
 			else
 				-- General context: show all
 				for type_name, _ in pairs(builtin.DATA_TYPES) do
@@ -894,6 +1023,27 @@ function handlers.textDocument_completion(params)
 				for func_name, _ in pairs(builtin.FUNCTIONS) do
 					add_item(func_name, 3, "Function")
 				end
+
+				-- Add declared variables in general context too
+				if doc.variables then
+					for name, info in pairs(doc.variables) do
+						if word_prefix == "" or name:upper():sub(1, #word_prefix) == word_prefix:upper() then
+							table.insert(items, {
+								label = name,
+								filterText = name,
+								kind = 13,
+								detail = "Variable (" .. (info.type or "VAR") .. "): " .. (info.data_type or "unknown"),
+								insertText = "#" .. name,
+								insertTextFormat = 1,
+							})
+						end
+					end
+				end
+
+				-- Add function/block call parameters if inside (...) context
+				if call_params then
+					add_param_items(items, call_params, word_prefix)
+				end
 			end
 		end
 	end
@@ -1655,16 +1805,25 @@ function handlers.textDocument_formatting(params)
 		return nil
 	end
 
-	local options = params.options or {}
 	local format_options = {
-		insertSpaces = options.insertSpaces,
+		insertSpaces = false,
-		tabSize = options.tabSize,
+		tabSize = 1,
-		indentSize = options.tabSize or 4,
+		indentSize = 1,
 	}
 
 	return formatter.format_document(doc.content, format_options)
 end
 
+function handlers.workspace_executeCommand(params)
+	if params.command ~= "SCLRescanWorkspaceTypes" then
+		return nil
+	end
+
+	plc_json.clear_cache()
+
+	return {}
+end
+
 local function handle_message(message)
 	if message.method == "$/cancelRequest" then
 		return nil

src/plc_json.lua

@@ -127,7 +127,7 @@ local function parse_scl_type_file(content)
       fb_inouts = {}
       current_fb_section = nil
     elseif in_fb and trimmed:match("^END_FUNCTION_BLOCK") then
-      if fb_name and (#fb_inputs > 0 or #fb_outputs > 0 or #fb_inouts > 0) then
+      if fb_name then
         types[fb_name] = {
           name = fb_name,
           kind = "function_block",