tia-lsp.nvim - Neovim Plugin for Siemens TIA Portal

A Neovim/LazyVim plugin that launches the tia-lsp language server and adds editor-specific features for Siemens TIA Portal languages. Currently supports SCL (Structured Control Language), with planned support for STL/AWL, LAD, and FBD.

Features

Feature	Description
Auto-Prefix	Automatically adds # prefix to local variables (like TIA Portal)
Multiline Parameters	Fill FB/Function call parameters across multiple lines with <Space>mp or :SCLMultilineParams
Tab Navigation	Jump between parameters with <Tab> in insert mode
Workspace UDT Scanner	Scans project for user-defined types (.udt files)
Workspace Global DB Scanner	Scans project for global data blocks (.db files)
blink.cmp Integration	Smart completion source for blink.cmp
Attribute Block Toggle	Interactive expand/collapse of {...} blocks with <Leader>xa
Tree-sitter Highlighting	Syntax highlighting via tree-sitter queries

Installation

The plugin auto-detects the mason-installed tia-lsp executable via vim.fn.exepath("tia-lsp") and falls back to lua <server_path> for manual installs.

LazyVim + Mason (Recommended)

1. Add the mason registry as a lazy.nvim plugin:

   -- ~/.config/nvim/lua/plugins/tia-mason-registry.lua
   return {
     url = "https://gitea.l-tech.rs/lazar/tia-mason-registry.git",
     name = "tia-mason-registry",
     lazy = false,  -- must be available before mason setup
   }
   

2. Register the registry with mason:

   -- ~/.config/nvim/lua/plugins/mason.lua
   return {
     "mason-org/mason.nvim",
     opts = {
       registries = {
         "file:" .. vim.fn.expand("~/.local/share/nvim/lazy/tia-mason-registry"),
         "github:mason-org/mason-registry",
       },
     },
   }
   

3. Add the plugin:

   -- ~/.config/nvim/lua/plugins/tia-lsp.lua
   return {
     "lazar/tia-lsp.nvim",
     ft = "scl",
     lazy = true,
     dependencies = {
       "neovim/nvim-lspconfig",
       "nvim-treesitter/nvim-treesitter",
       "saghen/blink.cmp",
     },
     config = function()
       require("tia_lsp").setup({
         lsp = {
           on_attach = function(client, bufnr)
             -- custom keymaps
           end,
         },
         cmp = true,              -- Enable blink.cmp integration
         workspace_types = true,  -- Enable workspace UDT scanning
         auto_prefix = true,      -- Enable auto-# prefixing
         debug = false,
       })
     end,
   }
   

4. Install:

   :MasonInstall yq       " one-time prerequisite for file: registry
   :MasonInstall tia-lsp  " installs the LSP server
   

5. Verify: open a .scl file and run :LspInfo — tia_lsp should be attached.

Manual Setup (without Mason)

require("tia_lsp").setup({
  server_path = "/path/to/tia-lsp/src/main.lua",  -- only used if tia-lsp is not on PATH
  ts_parser_url = "https://gitea.l-tech.rs/lazar/tia-lsp.git",
  cmp = true,
  workspace_types = true,
  auto_prefix = true,
})

Configuration Options

Option	Type	Default	Description
server_path	string	~/dev/tia-lsp/src/main.lua	Path to LSP server (only used if tia-lsp is not on PATH)
ts_parser_url	string	file://~/dev/tia-lsp	URL passed to nvim-treesitter for the SCL parser source
lsp.on_attach	function	nil	Custom LSP attach callback
lsp.formatting	boolean	false	Enable format command
cmp	boolean	true	Enable blink.cmp integration
workspace_types	boolean	true	Enable workspace UDT scanning
auto_prefix	boolean	true	Enable auto-# prefixing
project_root	string	nil	Custom project root
library_paths	table	{}	Additional library paths
debug	boolean	false	Enable debug logging

Commands

Command	Description
:SCLShowVariables	Show local variables in current file
:SCLShowWorkspaceTypes	Show workspace UDTs, FBs, and Global DBs count
:SCLRescanWorkspaceTypes	Rescan workspace for types and DBs
:SCLPrefixWord	Manually prefix current word with #
:SCLMultilineParams	Fill multiline parameters for FB/Function call
:SCLFormat	Format current SCL file
:SCLToggleAttrBlock	Toggle attribute block under cursor
:SCLExpandAllAttrBlocks	Expand all {...} blocks in buffer
:SCLCollapseAllAttrBlocks	Collapse all matching attribute blocks

Keybindings

Key	Action
K	Hover (show variable info)
gd	Go to Definition
<leader>s	Document Symbols
<leader>w	Workspace Symbols
<Space>mp	Fill multiline FB/Function parameters (insert mode)
<Tab>	Jump to next parameter (insert mode)
<Leader>xa	Toggle attribute block under cursor
<Leader>xae	Expand all attribute blocks
<Leader>xac	Collapse all attribute blocks
<leader>fw	Workspace Symbols (Telescope)
<leader>ca	Code Actions

Attribute Block Toggle

Interactive expand/collapse of SCL variable attribute blocks:

-- Before: Verbose attributes
statCounter{EXTERNALACCESSIBLE := 'false'; EXTERNALVISIBLE := 'false'} : Int;

-- After: Collapsed
statCounter{...} : Int;

Usage:

• Place cursor inside any {...} block
• Press <Leader>xa to toggle expand/collapse
• Use <Leader>xae to expand all blocks in buffer
• Use <Leader>xac to collapse all blocks

Note: Collapsed blocks are automatically expanded before saving to preserve full content on disk.

Filetype Detection

The plugin includes ftdetect/scl.vim which registers the following file extensions as scl filetype:

• *.scl — SCL source files
• *.udt — User-defined type files
• *.db — Data block files

Project Structure

tia-lsp.nvim/
├── lua/
│   ├── tia_lsp/                 # Plugin entry point
│   │   ├── init.lua             # Main setup (vim.lsp.start, exepath detection)
│   │   └── plugins/
│   │       └── scl.lua          # LazyVim plugin spec (SCL filetype)
│   └── tia/                     # Language modules (shared across TIA languages)
│       ├── auto_prefix.lua      # Auto-# prefixing
│       ├── attr_toggle.lua      # Attribute block expand/collapse
│       ├── blink_cmp_source.lua # blink.cmp completion source
│       ├── builtin_instructions.lua
│       ├── db_parser.lua        # Global DB parser
│       ├── fb_parser.lua        # Function Block parser
│       ├── multiline_params.lua # Multiline parameter filling
│       ├── udt_parser.lua       # UDT parser
│       ├── variables.lua        # Variable extraction
│       └── workspace_types.lua  # Workspace scanning
├── queries/
│   └── scl/                     # Tree-sitter queries (per-language)
│       ├── highlights.scm       # Syntax highlighting
│       ├── indents.scm          # Indentation
│       ├── folds.scm            # Code folding
│       ├── locals.scm           # Variable scoping
│       └── tags.scm             # Navigation tags
├── ftdetect/
│   └── scl.vim                  # Filetype detection
└── test/                        # Plugin tests
    ├── run_tests.lua
    ├── test_harness.lua
    ├── test_udt.lua
    ├── test_db.lua
    ├── test_fb.lua
    └── test_integration.lua

Requirements

• Neovim 0.11+ (uses vim.lsp.start())
• tia-lsp — the LSP server (install via mason or manually)
• nvim-treesitter — Syntax highlighting
• blink.cmp — Optional, for completion
• Lua 5.1+ — LSP server runtime

Testing

lua test/run_tests.lua

Tests use files from a reference project (override with SCL_REF_PROJECT=/path/to/ref lua test/run_tests.lua).