feat: improve formatter and attribute block handling

- Format multi-line assignments with proper alignment
- Format FB calls in multiline style with parameter alignment
- Auto-expand collapsed attribute blocks before save
- Rename command from LspSCLFormat to SCLFormat
- Condense AGENTS.md and add testing section with reference project

AGENTS.md

@@ -1,6 +1,6 @@
 # AGENTS.md - SCL Language Server
 
-A unified Neovim/LazyVim plugin for Siemens SCL language support providing LSP, linting, formatting, syntax highlighting, and auto-completion.
+A Neovim/LazyVim plugin for Siemens SCL language support providing LSP, linting, formatting, syntax highlighting, and auto-completion.
 
 ## Build/Lint/Test Commands
 
@@ -12,7 +12,7 @@ lua src/main.lua --test       # Direct test execution
 
 # Tree-sitter Parser
 tree-sitter generate          # Generate parser from grammar.js
-tree-sitter test              # Run parser tests
+tree-sitter test              # Run all parser tests
 tree-sitter parse <file.scl>  # Parse single SCL file
 
 # Lua Linting
@@ -31,11 +31,10 @@ scl_lsp/
 │   ├── formatter.lua       # Document formatter
 │   ├── treesitter.lua      # Tree-sitter integration
 │   ├── plc_json.lua        # External UDT/DB loading
-│   ├── builtin_instructions.lua  # TIA Portal built-in types/FBs/functions
+│   ├── builtin_instructions.lua  # TIA Portal built-in types
 │   └── json.lua            # JSON encoder/decoder
 ├── lua/scl/                 # Neovim plugin (uses require)
 │   ├── init.lua            # Main plugin setup
-│   ├── blink_cmp_source.lua
 │   ├── udt_parser.lua      # UDT parser
 │   ├── db_parser.lua       # Global DB parser
 │   ├── fb_parser.lua       # Function Block parser
@@ -43,34 +42,26 @@ scl_lsp/
 │   ├── workspace_types.lua # Workspace scanning
 │   ├── multiline_params.lua
 │   ├── auto_prefix.lua
-│   └── attr_toggle.lua       # Interactive attribute block toggle
+│   └── attr_toggle.lua
 ├── queries/                 # Tree-sitter queries
-│   ├── highlights.scm
-│   ├── indents.scm
-│   └── folds.scm
 └── grammar.js               # Tree-sitter grammar
 ```
 
 ## Filetype Detection
 
-The LSP requires the `scl` filetype to be set. Add to your Neovim config (e.g., `ftdetect/scl.vim`):
-
+Required in Neovim config (ftdetect/scl.vim):
 ```vim
 au BufRead,BufNewFile *.scl set filetype=scl
 au BufRead,BufNewFile *.udt set filetype=scl
 au BufRead,BufNewFile *.db set filetype=scl
 ```
 
-This enables LSP features (completion, goto definition, hover, etc.) for all SCL-related file types.
-
 ## Code Style Guidelines
 
 ### Module Pattern
 ```lua
--- File header comment
 local M = {}
 
--- Private cache
 local cache = {}
 
 function M.public_function()
@@ -89,8 +80,8 @@ return M
 - Booleans: prefix with `is_`, `has_` (e.g., `is_udt`, `has_members`)
 
 ### Imports
-- `lua/scl/` modules: use `require("scl.module_name")`
-- `src/` modules: use `dofile(script_path .. "/module.lua")`
+- `lua/scl/` modules: `require("scl.module_name")`
+- `src/` modules: `dofile(script_path .. "/module.lua")`
 - External dependencies: wrap in `pcall()` for safety
 
 ### Code Formatting
@@ -99,6 +90,9 @@ return M
 - Max line length: 120 characters
 - No trailing whitespace
 
+### Comments
+**DO NOT ADD COMMENTS** in code unless explicitly requested by the user.
+
 ### Parser Module API
 All parser modules must implement:
 - `parse_*_file(filepath)` - Parse and cache
@@ -121,291 +115,54 @@ function M.clear_cache()
 end
 ```
 
-## Lua Reserved Keywords
-
-Cannot use reserved keywords as table keys directly:
-```lua
--- WRONG: syntax error
-local range = { start = pos1, end = pos2 }
-
--- CORRECT: bracket notation
-local range = { start = pos1, ["end"] = pos2 }
-```
-
-Critical for LSP range objects with `end` field.
-
-## Error Handling
-
-### Return Pattern
+### Error Handling
 ```lua
 function M.parse_file(filepath)
   local file = io.open(filepath, "r")
   if not file then
     return nil, "Cannot open file: " .. filepath
   end
-  -- ... parse logic
   return result
 end
-```
 
-### External Dependencies
-```lua
+-- External dependencies
 local ok, module = pcall(require, "some_module")
 if ok and module then
   module.do_something()
 end
 ```
 
-## Diagnostics
-
-The LSP validates data types and provides warnings for unknown types. It recognizes:
-- **Elementary data types** - BOOL, BYTE, WORD, DWORD, LWORD, CHAR, WCHAR, STRING, WSTRING, INT, DINT, LINT, USINT, SINT, UINT, UDINT, ULINT, REAL, LREAL, TIME, DATE, TOD, TIME_OF_DAY, DATE_AND_TIME, DT, S5TIME, LTIME, DTL
-- **Timer/counter types** - IEC_TIMER, TON_TIME, TOF_TIME, TONR_TIME, TP_TIME, CTU, CTD, CTUD
-- **TIA Portal built-in instructions** - Functions and function blocks
-- **Workspace types** - UDTs from `.udt` files and data blocks from `.db` files
-
-## Completion Triggers
-- `#` - Local variables (after BEGIN)
-- `.` - Member access (UDT/DB)
-- `"` - Global DB names
-- `(` - FB/Function parameters
-- ` ` (space) - General completion
-- `:` - Type declaration (in VAR section)
-
-### Completion Types
-The LSP provides auto-completion for:
-- **Local variables** - Variables declared in VAR sections
-- **UDT types** - User-defined types from `.udt` files
-- **Global DBs** - Data blocks from `.db` files  
-- **Elementary types** - BOOL, INT, DINT, REAL, TIME, etc.
-- **TIA Portal built-in FBs** - TON, TOF, TP, CTU, CTD, CTUD, R_TRIG, etc.
-- **TIA Portal built-in functions** - ADD, SUB, MUL, DIV, SIN, COS, SQRT, etc.
-
-## Formatter Options
-
-The formatter supports collapsing verbose attribute blocks:
+## Lua Reserved Keywords
 
+Cannot use reserved keywords as table keys directly:
 ```lua
--- Before formatting:
-statCntrPartsIn{EXTERNALACCESSIBLE := 'false'; EXTERNALVISIBLE := 'false'} : Int;
+-- WRONG
+local range = { start = pos1, end = pos2 }
 
--- After formatting:
-statCntrPartsIn{...} : Int;
+-- CORRECT
+local range = { start = pos1, ["end"] = pos2 }
 ```
 
-### Formatter Configuration
-```lua
-local options = {
-  insertSpaces = false,
-  tabSize = 1,
-  collapseAttributes = false,  -- Disabled by default (see note below)
-  collapsePatterns = {        -- Override default patterns
-    "^%s*{%s*EXTERNAL",
-    "^%s*{ S7_",
-  },
-  extendCollapsePatterns = {  -- Add custom patterns
-    "^%s*{%s*CUSTOM",
-  },
-}
-```
+Critical for LSP range objects with `end` field.
 
-**Note:** `collapseAttributes` is disabled by default to preserve compatibility with the interactive toggle feature (`:SCLToggleAttrBlock`). When the formatter automatically collapses blocks, the original content is lost. To use both formatting and toggle:
-1. Format with `:LspSCLFormat` (preserves original content)
-2. Manually collapse with `:SCLCollapseAllAttrBlocks` (stores original content)
-3. Now toggle/expand works correctly
+## Type System
 
-### Default Collapse Patterns
-The `:SCLCollapseAllAttrBlocks` command uses case-insensitive patterns:
-- `EXTERNAL` - Variable attributes: `{EXTERNALACCESSIBLE := 'false'; EXTERNALVISIBLE := 'false'}`
-- `S7_` - Block attributes: `{S7_Optimized_Access := 'TRUE'}`
-- `NonRetain` - NonRetain attribute: `{NonRetain}`
-- `Retain` - Retain attribute: `{Retain}`
-- `%w+ :=` - Generic attributes with assignments: `{key := 'value'}`
-- `%w+` - Single word attributes: `{SomeAttribute}`
-
-Works in `.scl`, `.udt`, and `.db` files.
-
-### Per-Variable Collapse Rules
-Control collapsing per variable using rules (evaluated before global patterns):
-
-```lua
-local options = {
-  collapseVariableRules = {
-    -- Collapse attributes for variables starting with "stat"
-    {
-      variablePattern = "^stat",
-      collapse = true,
-    },
-    -- Never collapse for "temp" prefix variables
-    {
-      variablePattern = "^temp",
-      collapse = false,
-    },
-    -- Collapse only if both variable AND attribute match
-    {
-      variablePattern = "^config",
-      attributePattern = "EXTERNAL",
-      collapse = true,
-    },
-  },
-}
-```
-
-**Rule properties:**
-- `variablePattern` - Lua pattern to match variable name (optional)
-- `attributePattern` - Lua pattern to match attribute content (optional)
-- `collapse` - `true` to collapse to `{...}`, `false` to keep expanded
-
-Rules are checked in order; first match wins.
-
-## Commands
-
-| Command | Description |
-|---------|-------------|
-| `:SCLShowVariables` | Show local variables |
-| `:SCLShowWorkspaceTypes` | Show workspace types count |
-| `:SCLRescanWorkspaceTypes` | Rescan workspace |
-| `:SCLPrefixWord` | Prefix word with `#` |
-| `:SCLMultilineParams` | Fill FB parameters |
-| `:LspSCLFormat` | Format SCL file |
-| `:SCLToggleAttrBlock` | Toggle attribute block under cursor |
-| `:SCLExpandAllAttrBlocks` | Expand all `{...}` blocks in buffer |
-| `:SCLCollapseAllAttrBlocks` | Collapse all matching attribute blocks |
-
-## LSP Features
-
-### Goto Declaration (`gD`)
-The LSP supports goto declaration functionality for:
-- **Functions** - Jump to function definition in `.scl` files
-- **Function Blocks (FB)** - Jump to FB definition in `.scl` files
-- **Data Blocks (DB)** - Jump to DB definition in `.scl` and `.db` files
-- **User-Defined Types (UDT)** - Jump to type definition in `.scl` and `.udt` files
-
-Usage: Place cursor on a variable or type name and press `gD` (or use LSP client command).
-
-## Auto-Editing Features
-
-### Auto-Uppercase Keywords
-When typing SCL keywords followed by a space, they are automatically converted to uppercase:
-- `if ` → `IF `
-- `then ` → `THEN `
-- `end_if` → `END_IF`
-- etc.
-
-Works in `.scl`, `.udt`, and `.db` files.
-
-### Auto-Semicolon for Control Structures
-When pressing Enter after an `END_*` control structure keyword, a semicolon is automatically added:
-- `END_IF` → `END_IF;`
-- `END_FOR` → `END_FOR;`
-- `END_WHILE` → `END_WHILE;`
-- `END_REPEAT` → `END_REPEAT;`
-- `END_CASE` → `END_CASE;`
-
-Block definitions (END_VAR, END_FUNCTION, etc.) are NOT affected.
-
-### Auto-Prefix Local Variables
-Local variables are automatically prefixed with `#` when typing space or semicolon after BEGIN:
-- `myVar := ` → `#myVar := `
-- `counter.in` → `#counter.in` (on dot)
-
-Can be toggled with `:lua require("scl.auto_prefix").toggle()`.
-
-## Keybindings (SCL/UDT files)
-
-### Attribute Block Toggle
-Interactive expand/collapse of individual `{...}` blocks (uses `<Leader>x` prefix):
-
-| Key | Mode | Description |
-|-----|------|-------------|
-| `<Leader>xa` | Normal/Insert | Toggle block under cursor |
-| `<Leader>xae` | Normal | Expand all collapsed blocks |
-| `<Leader>xac` | Normal | Collapse all attribute blocks |
-
-**How it works:**
-1. Place cursor inside any `{...}` block
-2. Press `<Leader>xa` to toggle between collapsed `{...}` and expanded content
-3. Original content is stored per-buffer and persists until buffer is closed
-4. Works on both formatter-collapsed blocks and manually collapsed ones
-
-### Other Keybindings
-
-| Key | Mode | Description |
-|-----|------|-------------|
-| `<Space>mp` | Insert | Fill multiline FB parameters |
-| `<Tab>` | Insert | Jump to next parameter or regular Tab |
-
-Note: `<Leader>` is typically `\` (backslash) or `<Space>` depending on your configuration.
-
-### Troubleshooting
-
-**If commands or keybindings don't work:**
-
-1. Check if setup() was called:
-   ```lua
-   :lua print(vim.inspect(require("scl_lsp")))
-   ```
-
-2. Verify commands exist:
-   ```vim
-   :command SCLToggleAttrBlock
-   ```
-   Should show the command definition.
-
-3. Check for errors during setup:
-   ```lua
-   :lua require("scl_lsp").setup({})
-   ```
-
-4. Verify leader key:
-   ```vim
-   :echo mapleader
-   ```
-   If empty, your leader is `\` (backslash).
-
-5. Manual test keybinding:
-   ```vim
-   :nmap <Leader>xa
-   ```
-   Should show the mapping.
-
-### Attribute Toggle After Formatting
-
-**Note:** After using `:LspSCLFormat`, all collapsed attribute blocks will be expanded and the toggle state is reset. This is because formatting changes line numbers and positions. You can collapse blocks again after formatting.
+The LSP validates data types and provides warnings for unknown types:
+- **Elementary**: BOOL, BYTE, WORD, DWORD, INT, DINT, REAL, TIME, STRING, etc.
+- **Timer/counter**: IEC_TIMER, TON_TIME, TOF_TIME, CTU, CTD, CTUD
+- **Built-in FBs**: TON, TOF, TP, R_TRIG, F_TRIG, etc.
+- **Built-in functions**: ADD, SUB, MUL, DIV, SIN, COS, SQRT, etc.
+- **Workspace types**: UDTs from `.udt` files, DBs from `.db` files
 
 ## Testing
 
-Manual testing using: `~/dev/siemens/projects/scl_lang_support_lazyvim_ref_project`
-
-Workflow:
-1. Open `.scl` file in Neovim
-2. Test LSP features (hover, completion, go-to-definition)
-3. Verify diagnostics
-4. Test formatting
-5. Check workspace scanning
-
-## LSP Implementation Notes
-
-### Method Name Conversion
-```lua
-local method_name = message.method:gsub("/", "_")
-local handler = handlers[method_name]
+Use the reference project for testing:
+```
+~/dev/siemens/projects/scl_lang_support_lazyvim_ref_project/
 ```
 
-### Request vs Notification
-```lua
-if message.id then
-  -- Request: send response
-  return { id = message.id, result = result }
-end
--- Notification: no response needed
-```
-
-### Script Path Pattern
-```lua
-local script_path = debug.getinfo(1, "S").source:gsub("^@", ""):match("(.*/)") or ""
-if script_path == "" then
-  script_path = "."
-end
-package.path = package.path .. ";" .. script_path .. "/?.lua"
-```
+Contains `.scl`, `.db`, `.udt`, and `.xml` files for comprehensive testing of:
+- LSP features (hover, completion, go-to-definition)
+- Formatter (`:SCLFormat`)
+- Attribute block toggle
+- Workspace type scanning

README.md

@@ -27,7 +27,9 @@ A comprehensive Neovim/LazyVim plugin providing **Language Server Protocol (LSP)
 ### Formatter
 | Feature | Description |
 |---------|-------------|
-| **Document Formatting** | Format entire SCL files |
+| **Document Formatting** | Format entire SCL files with `:SCLFormat` |
+| **Multi-line Assignments** | Preserves and formats multi-line expressions with proper alignment |
+| **FB Call Formatting** | Formats function block calls in multiline style |
 | **Indentation** | Proper block indentation |
 | **Keyword Casing** | Maintains SCL keyword casing |
 
@@ -119,8 +121,7 @@ require("scl_lsp").setup({
 | `:SCLRescanWorkspaceTypes` | Rescan workspace for types and DBs |
 | `:SCLPrefixWord` | Manually prefix current word with `#` |
 | `:SCLMultilineParams` | Fill multiline parameters for FB/Function call |
-| `:LspSCLFormat` | Format current SCL file |
-| `:SCLGeneratePlcJson` | Generate plc.data.json from data_types/ |
+| `:SCLFormat` | Format current SCL file |
 | `:SCLToggleAttrBlock` | Toggle attribute block under cursor |
 | `:SCLExpandAllAttrBlocks` | Expand all `{...}` blocks in buffer |
 | `:SCLCollapseAllAttrBlocks` | Collapse all matching attribute blocks |
@@ -159,7 +160,7 @@ statCounter{...} : Int;
 - Use `<Leader>xae` to expand all blocks in buffer
 - Use `<Leader>xac` to collapse all blocks
 
-**Note:** The formatter has automatic collapsing disabled by default to preserve compatibility with the toggle feature. Format with `:LspSCLFormat` first, then use `:SCLCollapseAllAttrBlocks` to collapse while preserving the ability to expand later.
+**Note:** Collapsed blocks are automatically expanded before saving to preserve full content on disk. Use `:SCLFormat` to format, then `:SCLCollapseAllAttrBlocks` to collapse while preserving the ability to expand later.
 
 ## External UDT Support
 

src/formatter.lua

@@ -5,11 +5,8 @@ local M = {}
 -- Default patterns for attribute blocks to collapse
 -- Users can extend these via options.collapse_patterns
 local DEFAULT_COLLAPSE_PATTERNS = {
-  -- Match S7 variable attributes: {EXTERNALACCESSIBLE := 'false'; ...}
   "^%s*{%s*EXTERNAL",
-  -- Match S7 block attributes: { S7_Optimized_Access := 'TRUE' } or {S7_...}
   "^%s*{%s*S7_",
-  -- Match generic attribute blocks with assignments
   "^%s*{%s*%w+%s*:=",
 }
 
@@ -26,20 +23,17 @@ end
 
 -- Block types with their corresponding enders
 local BLOCKS = {
-  -- Control structures
   ["IF"] = "END_IF",
   ["FOR"] = "END_FOR",
   ["WHILE"] = "END_WHILE",
   ["REPEAT"] = "END_REPEAT",
   ["CASE"] = "END_CASE",
   ["REGION"] = "END_REGION",
-  -- Declarations  
   ["FUNCTION"] = "END_FUNCTION",
   ["FUNCTION_BLOCK"] = "END_FUNCTION_BLOCK",
   ["ORGANIZATION_BLOCK"] = "END_ORGANIZATION_BLOCK",
   ["TYPE"] = "END_TYPE",
   ["STRUCT"] = "END_STRUCT",
-  -- VAR sections (special handling)
   ["VAR"] = "END_VAR",
   ["VAR_INPUT"] = "END_VAR",
   ["VAR_OUTPUT"] = "END_VAR",
@@ -50,7 +44,6 @@ local BLOCKS = {
   ["VAR_NON_RETAIN"] = "END_VAR",
 }
 
--- Keywords that don't change indent level themselves (handled specially)
 local SAME_LEVEL = {
   ["THEN"] = true,
   ["ELSE"] = true,
@@ -60,7 +53,6 @@ local SAME_LEVEL = {
   ["BEGIN"] = true,
 }
 
--- Control structure enders that need semicolons
 local NEEDS_SEMICOLON = {
   ["END_IF"] = true,
   ["END_FOR"] = true,
@@ -70,7 +62,6 @@ local NEEDS_SEMICOLON = {
   ["END_REGION"] = true,
 }
 
--- VAR keywords for special handling
 local VAR_KEYWORDS = {
   ["VAR"] = true,
   ["VAR_INPUT"] = true,
@@ -82,7 +73,6 @@ local VAR_KEYWORDS = {
   ["VAR_NON_RETAIN"] = true,
 }
 
--- Declaration keywords (reset indent)
 local DECLARATIONS = {
   ["FUNCTION"] = true,
   ["FUNCTION_BLOCK"] = true,
@@ -91,31 +81,32 @@ local DECLARATIONS = {
   ["STRUCT"] = true,
 }
 
+local CONTINUATION_OPERATORS = {
+  ["AND"] = true,
+  ["OR"] = true,
+  ["XOR"] = true,
+  ["NOT"] = true,
+  ["MOD"] = true,
+}
+
 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"
   
-  -- Attribute block collapsing options
-  -- NOTE: Disabled by default to preserve compatibility with attr_toggle.
-  -- When formatter collapses blocks, the original content is lost.
-  -- Use :SCLCollapseAllAttrBlocks after formatting instead.
   local collapse_attributes = options.collapseAttributes
   if collapse_attributes == nil then
-    collapse_attributes = false  -- Default: disabled to preserve toggle functionality
+    collapse_attributes = false
   end
   
-  -- User can provide custom patterns or extend defaults
   local collapse_patterns = options.collapsePatterns or DEFAULT_COLLAPSE_PATTERNS
   if options.extendCollapsePatterns then
-    -- Extend defaults with user patterns
     for _, pattern in ipairs(options.extendCollapsePatterns) do
       table.insert(collapse_patterns, pattern)
     end
   end
 
-  -- Parse content into lines
   local lines = {}
   for line in content:gmatch("([^\n]*)\n") do
     table.insert(lines, line)
@@ -128,18 +119,9 @@ function M.format_document(content, options)
     return { { range = range(0, 0, 0, 0), newText = "" } }
   end
 
-  -- Stack of active blocks
-  -- Each entry: { type = "IF", indent = 1, is_case = false }
   local stack = {}
   local formatted_lines = {}
 
-  -- FB call state
-  local in_fb_call = false
-  local fb_name_length = 0
-  local fb_call_first_line = false
-  local fb_paren_offset = 0  -- Offset to align parameters with opening paren
-
-  -- Helper: get current indent string
   local function get_indent()
     local level = 0
     for _, block in ipairs(stack) do
@@ -150,100 +132,26 @@ function M.format_document(content, options)
     return string.rep(indent_char, level)
   end
 
-  -- Helper: get continuation indent for FB calls
-  local function get_continuation_indent()
-    local base = get_indent()
-    return base .. string.rep(" ", fb_paren_offset)
+  local function is_assignment_continuation(trimmed)
+    if not trimmed then return false end
+    local first_word = trimmed:match("^(%w+)")
+    if first_word and CONTINUATION_OPERATORS[first_word:upper()] then
+      return true
+    end
+    return false
   end
 
--- Helper: check if line is a case label
-	local function is_case_label(trimmed)
-		return trimmed:match("^[%w_#]+%s*:%s*$") ~= nil
-	end
-
-	-- Helper: extract variable name from a line (before any attribute block)
-	local function extract_variable_name(line)
-		-- Match pattern: variableName{...} or variableName : type
-		-- Variable names can contain letters, numbers, underscores
-		local var_name = line:match("^%s*([%w_]+)%s*[%({:]")
-		return var_name
-	end
-
-	-- Helper: collapse attribute blocks like {EXTERNALACCESSIBLE := 'false'; ...} to {...}
-	local function collapse_attribute_block(line)
-		if not collapse_attributes then
-			return line
-		end
-
-		-- Check if line contains an attribute block
-		local attr_start, attr_end = line:find("{.-}")
-		if not attr_start then
-			return line
-		end
-
-		-- Extract the content before the attribute block
-		local before_attr = line:sub(1, attr_start - 1)
-		local attr_content = line:sub(attr_start, attr_end)
-		local after_attr = line:sub(attr_end + 1)
-
-		-- Extract variable name for per-variable rules
-		local var_name = extract_variable_name(line)
-
-		-- Check per-variable collapse rules first (highest priority)
-		if options.collapseVariableRules and var_name then
-			for _, rule in ipairs(options.collapseVariableRules) do
-				local var_pattern = rule.variablePattern
-				local attr_pattern = rule.attributePattern
-				local should_collapse = rule.collapse
-
-				-- Check if variable name matches
-				local var_matches = not var_pattern or var_name:match(var_pattern)
-
-				-- Check if attribute content matches (if specified)
-				local attr_matches = not attr_pattern or attr_content:match(attr_pattern)
-
-				if var_matches and attr_matches then
-					if should_collapse then
-						return before_attr .. "{...}" .. after_attr
-					else
-						-- Explicitly don't collapse this match
-						return line
-					end
-				end
-			end
-		end
-
-		-- Check if this attribute block matches any global collapse pattern
-		for _, pattern in ipairs(collapse_patterns) do
-			if attr_content:match(pattern) then
-				-- Collapse to {...}
-				return before_attr .. "{...}" .. after_attr
-			end
-		end
-
-		return line
-	end
-
-  -- Helper: check if line starts FB call
-  local function is_fb_call_start(line)
-    local trimmed = line:gsub("^%s+", "")
-    if not (trimmed:match("^#%w+") or trimmed:match('^"')) then
+  local function is_fb_call_start(trimmed)
+    if not (trimmed:match("^#?%w+") or trimmed:match('^"')) then
       return false
     end
     local paren_pos = trimmed:find("%(")
     if not paren_pos then return false end
     local assign_pos = trimmed:find(":=")
     if assign_pos and assign_pos < paren_pos then return false end
-    local open_count, close_count = 0, 0
-    for i = 1, #trimmed do
-      local c = trimmed:sub(i, i)
-      if c == "(" then open_count = open_count + 1
-      elseif c == ")" then close_count = close_count + 1 end
-    end
-    return open_count > 0 and close_count < open_count
+    return true
   end
 
-  -- Helper: check if FB call ends on this line
   local function fb_call_has_closing(line)
     local open_count, close_count = 0, 0
     for i = 1, #line do
@@ -251,23 +159,129 @@ function M.format_document(content, options)
       if c == "(" then open_count = open_count + 1
       elseif c == ")" then close_count = close_count + 1 end
     end
-    -- FB call ends when we have closes > opens, not when they're equal
-    -- (equal means no parens on this line, which shouldn't end the call)
     return close_count > 0 and close_count >= open_count
   end
 
-  -- Helper: check if line ends with comma (FB call continuation)
-  local function is_continuation(line)
-    return line:gsub("^%s+", ""):gsub("%s+$", ""):match(".*,$") ~= nil
+  local function format_fb_call_multiline(fb_lines, base_indent, param_indent)
+    local result = {}
+    local all_text = table.concat(fb_lines, " ")
+    
+    local fb_name = all_text:match("^(#?[%w_]+)%s*%(")
+    if not fb_name then
+      for _, l in ipairs(fb_lines) do
+        table.insert(result, base_indent .. l)
+      end
+      return result
+    end
+    
+    local paren_start = all_text:find("%(")
+    local paren_end = all_text:find("%);%s*$") or all_text:find("%)%s*$")
+    if not paren_start or not paren_end then
+      for _, l in ipairs(fb_lines) do
+        table.insert(result, base_indent .. l)
+      end
+      return result
+    end
+    
+    local params_text = all_text:sub(paren_start + 1, paren_end - 1)
+    
+    local params = {}
+    local current_param = ""
+    local depth = 0
+    for i = 1, #params_text do
+      local c = params_text:sub(i, i)
+      if c == "(" then
+        depth = depth + 1
+        current_param = current_param .. c
+      elseif c == ")" then
+        depth = depth - 1
+        current_param = current_param .. c
+      elseif c == "," and depth == 0 then
+        local trimmed_param = current_param:match("^%s*(.-)%s*$")
+        if trimmed_param ~= "" then
+          table.insert(params, trimmed_param)
+        end
+        current_param = ""
+      else
+        current_param = current_param .. c
+      end
+    end
+    local last_param = current_param:match("^%s*(.-)%s*$")
+    if last_param and last_param ~= "" then
+      table.insert(params, last_param)
+    end
+    
+    if #params == 0 then
+      return { base_indent .. fb_name .. "();" }
+    end
+    
+    table.insert(result, base_indent .. fb_name .. "(" .. params[1] .. ",")
+    
+    for i = 2, #params do
+      local closing = (i == #params) and ");" or ","
+      table.insert(result, param_indent .. params[i] .. closing)
+    end
+    
+    return result
+  end
+
+  local function is_case_label(trimmed)
+    return trimmed:match("^[%w_#]+%s*:%s*$") ~= nil
+  end
+
+  local function extract_variable_name(line)
+    local var_name = line:match("^%s*([%w_]+)%s*[%({:]")
+    return var_name
+  end
+
+  local function collapse_attribute_block(line)
+    if not collapse_attributes then
+      return line
+    end
+
+    local attr_start, attr_end = line:find("{.-}")
+    if not attr_start then
+      return line
+    end
+
+    local before_attr = line:sub(1, attr_start - 1)
+    local attr_content = line:sub(attr_start, attr_end)
+    local after_attr = line:sub(attr_end + 1)
+
+    local var_name = extract_variable_name(line)
+
+    if options.collapseVariableRules and var_name then
+      for _, rule in ipairs(options.collapseVariableRules) do
+        local var_pattern = rule.variablePattern
+        local attr_pattern = rule.attributePattern
+        local should_collapse = rule.collapse
+
+        local var_matches = not var_pattern or var_name:match(var_pattern)
+        local attr_matches = not attr_pattern or attr_content:match(attr_pattern)
+
+        if var_matches and attr_matches then
+          if should_collapse then
+            return before_attr .. "{...}" .. after_attr
+          else
+            return line
+          end
+        end
+      end
+    end
+
+    for _, pattern in ipairs(collapse_patterns) do
+      if attr_content:match(pattern) then
+        return before_attr .. "{...}" .. after_attr
+      end
+    end
+
+    return line
   end
 
-  -- Helper: extract keyword from line
   local function get_keyword(trimmed)
-    -- Match VAR_IN_OUT, VAR_CONSTANT, etc. (words with multiple underscores)
     return trimmed:match("^([%w_]+)") or trimmed:match("^(%w+)")
   end
 
-  -- Helper: find case block in stack
   local function find_case_block()
     for i = #stack, 1, -1 do
       if stack[i].type == "CASE" then
@@ -277,7 +291,6 @@ function M.format_document(content, options)
     return nil, nil
   end
 
-  -- Helper: pop blocks until matching ender found
   local function pop_to_ender(ender_type)
     while #stack > 0 do
       local top = stack[#stack]
@@ -290,77 +303,83 @@ function M.format_document(content, options)
     return false
   end
 
-  -- Process each line
+  -- State tracking
+  local in_fb_call = false
+  local fb_call_lines = {}
+  local fb_base_indent = ""
+  local fb_param_indent = ""
+  
+  local in_assignment = false
+  local assignment_continuation_indent = ""
+
   for line_num, line in ipairs(lines) do
     local trimmed = line:gsub("^%s+", ""):gsub("%s+$", "")
     local kw = get_keyword(trimmed)
 
-		-- Handle empty lines (preserve as-is)
     if trimmed == "" then
       table.insert(formatted_lines, "")
       goto continue
     end
 
-		-- Handle comments (re-indent with current level)
     if trimmed:match("^//") or trimmed:match("^%(") then
-			-- Apply attribute block collapsing to comments too (for consistency)
       local collapsed = collapse_attribute_block(trimmed)
       table.insert(formatted_lines, get_indent() .. collapsed)
       goto continue
     end
 
-		-- Apply attribute block collapsing
     trimmed = collapse_attribute_block(trimmed)
 
-    -- Check for FB call start
+    -- Check if continuing assignment
+    if in_assignment and is_assignment_continuation(trimmed) then
+      table.insert(formatted_lines, assignment_continuation_indent .. trimmed)
+      goto continue
+    end
+    in_assignment = false
+
+    -- Check if starting FB call
     if not in_fb_call and is_fb_call_start(trimmed) then
-      local fb_name = trimmed:match("^#?([%w_]+)") or trimmed:match('^"?([%w_]+)"?')
-      if fb_name then
-        fb_name_length = #fb_name
       in_fb_call = true
-        fb_call_first_line = true
-        -- Calculate paren offset: find position of opening paren + 1
-        -- This aligns continuation lines with the content inside the parens
-        local paren_pos = trimmed:find("%(")
-        if paren_pos then
-          fb_paren_offset = paren_pos + 1  -- +1 to align with content after paren
+      fb_call_lines = { trimmed }
+      fb_base_indent = get_indent()
+      local fb_name = trimmed:match("^(#?[%w_]+)")
+      if fb_name then
+        fb_param_indent = fb_base_indent .. string.rep(" ", #fb_name + 1)
       else
-          fb_paren_offset = fb_name_length + 2
-        end
-      end
+        fb_param_indent = fb_base_indent .. string.rep(" ", 4)
       end
       
-    -- Handle FB call lines
-    if in_fb_call then
-      local is_first = fb_call_first_line
-      local has_closing = fb_call_has_closing(trimmed)
-      local is_cont = is_continuation(trimmed)
-
-      local formatted
-      if has_closing then
-        formatted = (is_first and get_indent() or get_continuation_indent()) .. trimmed
+      if fb_call_has_closing(trimmed) then
+        local formatted_fb = format_fb_call_multiline(fb_call_lines, fb_base_indent, fb_param_indent)
+        for _, fline in ipairs(formatted_fb) do
+          table.insert(formatted_lines, fline)
+        end
         in_fb_call = false
-        fb_call_first_line = false
-      elseif is_cont then
-        formatted = is_first and (get_indent() .. trimmed) or (get_continuation_indent() .. trimmed)
-        fb_call_first_line = false
-      else
-        formatted = get_continuation_indent() .. trimmed
+        fb_call_lines = {}
+      end
+      goto continue
+    end
+
+    -- Continue collecting FB call lines
+    if in_fb_call then
+      table.insert(fb_call_lines, trimmed)
+      if fb_call_has_closing(trimmed) then
+        local formatted_fb = format_fb_call_multiline(fb_call_lines, fb_base_indent, fb_param_indent)
+        for _, fline in ipairs(formatted_fb) do
+          table.insert(formatted_lines, fline)
+        end
+        in_fb_call = false
+        fb_call_lines = {}
       end
-      table.insert(formatted_lines, formatted)
       goto continue
     end
 
-    -- Handle block declarations (FUNCTION_BLOCK, etc.)
     if DECLARATIONS[kw] then
-      -- Clear stack for new block
       stack = {}
       table.insert(formatted_lines, trimmed)
       table.insert(stack, { type = kw, indent = 0, is_declaration = true })
       goto continue
     end
 
-    -- Handle declaration enders
     if kw and not BLOCKS[kw] then
       for starter, ender in pairs(BLOCKS) do
         if DECLARATIONS[starter] and kw == ender then
@@ -371,20 +390,15 @@ function M.format_document(content, options)
       end
     end
 
-    -- Handle BEGIN (transition to code section)
     if kw == "BEGIN" then
-      -- Pop any VAR blocks
       while #stack > 0 and VAR_KEYWORDS[stack[#stack].type] do
         table.remove(stack)
       end
       table.insert(formatted_lines, get_indent() .. trimmed)
-      -- BEGIN itself doesn't add indent, but code inside does
       goto continue
     end
 
-    -- Handle VAR section start
     if VAR_KEYWORDS[kw] then
-      -- Pop to declaration level
       while #stack > 0 and not stack[#stack].is_declaration do
         table.remove(stack)
       end
@@ -393,9 +407,7 @@ function M.format_document(content, options)
       goto continue
     end
 
-    -- Handle END_VAR
     if kw == "END_VAR" then
-      -- Pop VAR blocks
       while #stack > 0 and VAR_KEYWORDS[stack[#stack].type] do
         table.remove(stack)
       end
@@ -403,14 +415,10 @@ function M.format_document(content, options)
       goto continue
     end
 
-    -- Handle block enders (END_IF, END_FOR, etc.)
     if kw and BLOCKS[kw] == nil then
-      -- Check if it's an ender
       for starter, ender in pairs(BLOCKS) do
         if kw == ender and not DECLARATIONS[starter] then
-          -- Pop matching block
           pop_to_ender(kw)
-          -- Add semicolon if needed
           local formatted = get_indent() .. trimmed
           if NEEDS_SEMICOLON[kw] and trimmed:sub(-1) ~= ";" then
             formatted = formatted .. ";"
@@ -421,11 +429,9 @@ function M.format_document(content, options)
       end
     end
 
-    -- Handle same-level keywords (THEN, ELSE, ELSIF)
     if SAME_LEVEL[kw] then
       local formatted
       if kw == "THEN" then
-        -- Pop IF block temporarily to get correct indent
         local if_block = nil
         for i = #stack, 1, -1 do
           if stack[i].type == "IF" then
@@ -439,14 +445,11 @@ function M.format_document(content, options)
           formatted = get_indent() .. trimmed
         end
         table.insert(formatted_lines, formatted)
-        -- Push content block after THEN
         table.insert(stack, { type = "THEN_CONTENT", indent = #stack, no_indent = true })
       elseif kw == "ELSE" or kw == "ELSIF" then
-        -- Pop THEN_CONTENT if present
         if #stack > 0 and stack[#stack].type == "THEN_CONTENT" then
           table.remove(stack)
         end
-        -- Find IF block for correct indent
         local if_block = nil
         for i = #stack, 1, -1 do
           if stack[i].type == "IF" then
@@ -460,7 +463,6 @@ function M.format_document(content, options)
           formatted = get_indent() .. trimmed
         end
         table.insert(formatted_lines, formatted)
-        -- Push new content block
         table.insert(stack, { type = "THEN_CONTENT", indent = #stack, no_indent = true })
       else
         formatted = get_indent() .. trimmed
@@ -469,18 +471,14 @@ function M.format_document(content, options)
       goto continue
     end
 
-    -- Handle case labels
     if is_case_label(trimmed) then
       local case_block, case_idx = find_case_block()
       if case_block then
-        -- Pop to just after CASE
         while #stack > case_idx do
           table.remove(stack)
         end
-        -- Case label at CASE level + 1
         local label_indent = string.rep(indent_char, case_block.indent + 1)
         table.insert(formatted_lines, label_indent .. trimmed)
-        -- Push case content level
         table.insert(stack, { type = "CASE_LABEL", indent = case_block.indent + 1, no_indent = true })
       else
         table.insert(formatted_lines, get_indent() .. trimmed)
@@ -488,7 +486,6 @@ function M.format_document(content, options)
       goto continue
     end
 
-    -- Handle block starters (IF, FOR, CASE, REGION, etc.)
     if kw and BLOCKS[kw] and not VAR_KEYWORDS[kw] and not DECLARATIONS[kw] then
       local current_level = 0
       for _, block in ipairs(stack) do
@@ -502,9 +499,24 @@ function M.format_document(content, options)
       goto continue
     end
 
-    -- Regular line (including variable declarations inside VAR sections)
+    -- Regular line - check for assignment start
+    if trimmed:match(":=") then
+      local base_indent = get_indent()
+      local assign_pos = trimmed:find(":=")
+      if assign_pos then
+        local var_part = trimmed:sub(1, assign_pos - 1)
+        local var_trimmed = var_part:match("^(.-)%s*$")
+        assignment_continuation_indent = base_indent .. string.rep(" ", #var_trimmed + 4)
+        
+        if not trimmed:match(";%s*$") then
+          in_assignment = true
+        end
+      end
+    else
+      in_assignment = false
+    end
+
     local formatted = get_indent() .. trimmed
-    -- Add semicolon if it looks like it needs one
     if NEEDS_SEMICOLON[kw] and trimmed:sub(-1) ~= ";" then
       formatted = formatted .. ";"
     end
@@ -513,7 +525,6 @@ function M.format_document(content, options)
     ::continue::
   end
 
-  -- Join lines
   local result = table.concat(formatted_lines, "\n")
   if content:sub(-1) == "\n" then
     result = result .. "\n"
@@ -534,22 +545,7 @@ function M.get_formatting_options()
     trimTrailingWhitespace = true,
     insertFinalNewline = true,
     trimFinalNewlines = true,
-    collapseAttributes = false,  -- Disabled by default to preserve toggle functionality
-    -- Set to true to enable automatic collapsing during formatting:
-    -- collapseAttributes = true,
-    -- collapsePatterns = { ... },  -- Override default collapse patterns
-    -- extendCollapsePatterns = { ... },  -- Extend default patterns with custom ones
-    -- collapseVariableRules = {  -- Per-variable collapse rules (highest priority)
-    --   {
-    --     variablePattern = "^stat",  -- Match variable names starting with "stat"
-    --     attributePattern = "EXTERNAL",  -- Optional: also match attribute content
-    --     collapse = true,  -- true to collapse, false to expand
-    --   },
-    --   {
-    --     variablePattern = "^temp",  -- Match variables starting with "temp"
-    --     collapse = false,  -- Never collapse these
-    --   },
-    -- },
+    collapseAttributes = false,
   }
 end