Editor Setup (Neovim)

This chapter shows a working Neovim/LazyVim setup for Shape with:

• LSP (shape-lsp)
• Tree-sitter highlighting + foreign language injection (tree-sitter-shape)
• comment support (//) so gc/comment actions work

1. Install the LSP Binary

Option A: cargo (works everywhere)

cargo install shape-lsp

Option B: Mason (pending registry PR)

:MasonInstall shape-lsp

2. Install the Tree-sitter Parser

Option A: Build from source (works now)

cd shape/tree-sitter-shape
cc -shared -fPIC -O2 -o parser/shape.so src/parser.c -I src

This produces shape/tree-sitter-shape/parser/shape.so.

Option B: nvim-treesitter (coming soon — pending upstream PR)

:TSInstall shape

3. LazyVim Plugin Config

Create ~/.config/nvim/lua/plugins/shape.lua:

return {
  -- tree-sitter-shape: parser/shape.so + queries/shape/{highlights,injections}.scm
  -- Neovim discovers both automatically via runtimepath.
  -- Set this to the tree-sitter-shape directory in your Shape checkout.
  {
    dir = vim.fn.expand("~/src/shape/tree-sitter-shape"),
    name = "tree-sitter-shape-local",
    lazy = false,
    config = function()
      vim.filetype.add({ extension = { shape = "shape" } })
      vim.treesitter.language.register("shape", "shape")
      vim.api.nvim_create_autocmd("FileType", {
        pattern = "shape",
        callback = function()
          vim.treesitter.start()
        end,
      })
    end,
  },

  {
    "neovim/nvim-lspconfig",
    opts = function()
      vim.lsp.config.shape = {
        cmd = { "shape-lsp" },
        filetypes = { "shape" },
        root_markers = { ".git", "shape.toml" },
        -- Inlay-hint settings forwarded as initializationOptions.
        -- Shape-unique categories (e.g. bindingStorageClass) are
        -- OFF by default; flip to true to opt in.
        init_options = {
          shape = {
            inlayHints = {
              enable = true,
              -- bindingStorageClass = { enable = true },  -- Shape-unique opt-in
            },
          },
        },
      }

      vim.lsp.enable("shape")

      -- Optional: enable inlay hints globally (Neovim 0.10+)
      pcall(vim.lsp.inlay_hint.enable, true)
    end,
  },

  {
    "nvim-treesitter/nvim-treesitter",
    opts = function(_, opts)
      -- Ensure Python parser is installed for foreign block injection
      opts.ensure_installed = opts.ensure_installed or {}
      if not vim.tbl_contains(opts.ensure_installed, "python") then
        table.insert(opts.ensure_installed, "python")
      end
    end,
  },

  {
    "numToStr/Comment.nvim",
    opts = {},
    init = function()
      vim.api.nvim_create_autocmd("FileType", {
        pattern = "shape",
        callback = function()
          -- Fixes: "Option 'commentstring' is empty"
          vim.bo.commentstring = "// %s"
        end,
      })
    end,
  },
}

Adjust the dir path to point to tree-sitter-shape in your local Shape checkout.

4. How It Works

The tree-sitter-shape directory is added to Neovim’s runtimepath. Neovim discovers:

• parser/shape.so — the compiled parser (you build this yourself)
• queries/shape/highlights.scm — Shape syntax highlighting
• queries/shape/injections.scm — foreign language injection (Python, etc.)

The injection query is generic — it reads the language name from fn <language> name(...) { } and injects the matching tree-sitter parser. Any foreign language with an installed tree-sitter parser gets syntax highlighting automatically.

Note

:TSInstall shape support is coming soon (pending upstream PR to nvim-treesitter). Until then, build parser/shape.so yourself (see step 2). Injected language parsers (e.g., Python) already work via :TSInstall python.

5. Verify Setup

Open a .shape file and run:

:set ft?
:LspInfo
:InspectTree
:set commentstring?

Expected:

• filetype is shape
• shape LSP is attached
• :InspectTree shows the tree-sitter parse tree (including foreign_body nodes)
• commentstring is // %s

6. Rebuilding After Grammar Changes

When the tree-sitter grammar is updated, rebuild the parser:

cd shape/tree-sitter-shape
tree-sitter generate   # regenerates src/parser.c from grammar.js
cc -shared -fPIC -O2 -o parser/shape.so src/parser.c -I src

Then restart Neovim.

7. Common Issues

No LSP features (hover/completion/diagnostics)

• verify shape-lsp is on your $PATH (installed via cargo install shape-lsp)
• update to latest version:

cargo install shape-lsp --force

Foreign blocks have hover but no syntax highlighting

Tree-sitter injection handles syntax highlighting; the LSP handles hover/completions. For injection to work:

1. parser/shape.so must be built and in the runtimepath.
2. The foreign language’s tree-sitter parser must be installed (e.g., :TSInstall python).
3. vim.treesitter.start() must run for shape buffers (the config above does this).

Option 'commentstring' is empty

• ensure the FileType shape autocmd above is active
• reopen file or run :set commentstring=//\ %s

No Tree-sitter highlighting at all

• check that parser/shape.so exists in the tree-sitter-shape directory
• check :lua print(vim.treesitter.language.get_lang("shape")) returns "shape"
• check :lua print(vim.treesitter.highlighter.active[vim.api.nvim_get_current_buf()] ~= nil) returns true

8. Inlay Hint Settings

The Shape LSP honors a shape.* settings tree forwarded via the init_options slot (see the lspconfig block in §3) or — for live updates — via workspace/didChangeConfiguration. The inlay-hint master is ON by default; Shape-unique opt-in categories are OFF by default so the editor stays uncluttered:

Setting	Default	Description
shape.inlayHints.enable	true	Master toggle.
shape.inlayHints.typeHints	true	Inferred type hints on let bindings.
shape.inlayHints.parameterHints	true	Parameter-name hints at call sites.
shape.inlayHints.variableTypeHints	true	Inferred variable types where elided.
shape.inlayHints.returnTypeHints	true	Inferred return-type hints on fn declarations.
shape.inlayHints.chainHints	true	Intermediate-type hints on method-chain expressions.
shape.inlayHints.bindingStorageClass.enable	false (opt-in)	Shape-unique: surfaces the compiler’s BindingStorageClass (Direct / UniqueHeap / SharedCow / SharedAtomic / SharedAtomicMut) inline. Rendered with [… approx].

9. Notes

• LSP and runtime use the same module/loader architecture; keep your shape-lsp up to date (cargo install shape-lsp --force) when testing language changes.