Shape Language Server

A fully-featured Language Server Protocol (LSP) implementation for Shape, providing rich IDE support including diagnostics, completion, hover information, go-to-definition, and more.

Features

✅ Real-time Diagnostics - Parse, semantic, and type errors as you type ✅ Intelligent Completions - Context-aware autocomplete with 80+ built-ins + user-defined symbols ✅ Hover Information - Documentation, signatures, and type info on hover ✅ Signature Help - Parameter hints while typing function calls ✅ Go-to-Definition - Jump to symbol definitions (Ctrl+Click) ✅ Find References - See all usages of a symbol ✅ Document Symbols - Outline view of functions, patterns, variables ✅ Workspace Symbols - Search symbols across entire workspace

Architecture

Single Source of Truth: All language information comes from shape-core/metadata.rs - no hardcoded language features in the LSP. Adding a new built-in to Shape automatically makes it available in the LSP.

Installation

Building from Source

# Build the LSP server
cargo build --release -p shape-lsp

# The binary will be at:
# target/release/shape-lsp

Editor Integration

VSCode

Create .vscode/settings.json in your workspace:

{
  "shape.languageServer": {
    "enabled": true,
    "path": "/path/to/target/release/shape-lsp"
  }
}

Or use the generic LSP client extension:

1. Install "Generic LSP Client" extension
2. Add to settings.json:

{
  "genericLanguageServer.languageServerConfigs": {
    "shape": {
      "command": "/path/to/target/release/shape-lsp",
      "args": [],
      "filetypes": ["cql"],
      "initializationOptions": {}
    }
  }
}

Neovim (with nvim-lspconfig)

Add to your Neovim config:

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')

-- Define Shape LSP if not already defined
if not configs.shape then
  configs.shape = {
    default_config = {
      cmd = {'/path/to/target/release/shape-lsp'},
      filetypes = {'cql'},
      root_dir = lspconfig.util.root_pattern('.git', 'Cargo.toml'),
      settings = {},
    },
  }
end

-- Enable Shape LSP
lspconfig.shape.setup{}

Emacs (with lsp-mode)

Add to your Emacs config:

(require 'lsp-mode)

(add-to-list 'lsp-language-id-configuration '(shape-mode . "shape"))

(lsp-register-client
 (make-lsp-client
  :new-connection (lsp-stdio-connection "/path/to/target/release/shape-lsp")
  :major-modes '(shape-mode)
  :server-id 'shape-lsp))

Usage

Once installed, the LSP provides:

Diagnostics

Errors appear as red squiggles in real-time:

• Parse errors (syntax mistakes)
• Semantic errors (undefined variables)
• Type errors (type mismatches)

Completions

Type to get intelligent suggestions:

• User-defined variables, functions, patterns
• Built-in functions (sma, ema, rsi, etc.)
• Keywords (let, const, if, pattern, backtest, etc.)
• Snippets (pattern-def, function-def, strategy-template, etc.)
• Property completion: candle[0]. → open, close, high, low, volume

Hover

Hover over any symbol to see:

• Function signatures with parameter details
• Type information
• Documentation and examples
• Variable/constant types

Signature Help

Type sma( to see:

• Function signature
• Parameter names and types
• Documentation for each parameter
• Current parameter highlighted

Navigation

• Go-to-Definition: Ctrl+Click or F12 on any symbol
• Find References: Shift+F12 to see all usages
• Document Symbols: Ctrl+Shift+O for outline view
• Workspace Symbols: Ctrl+T to search across files

Development

Running Tests

cargo test -p shape-lsp

Running the LSP Server

# Stdio mode (for editor integration)
cargo run -p shape-lsp --bin shape-lsp

# With debug logging
RUST_LOG=shape_lsp=debug cargo run -p shape-lsp --bin shape-lsp

Architecture

shape-lsp/
├── src/
│   ├── main.rs              # Binary entrypoint (stdio server)
│   ├── lib.rs               # Library exports
│   ├── server.rs            # Main LSP server implementation
│   ├── document.rs          # Document manager (Rope-based storage)
│   ├── diagnostics.rs       # Error → LSP diagnostics converter
│   ├── completion.rs        # Intelligent completion provider
│   ├── hover.rs             # Hover information provider
│   ├── signature_help.rs    # Function signature hints
│   ├── definition.rs        # Go-to-definition & find references
│   ├── document_symbols.rs  # Outline view & symbol search
│   ├── symbols.rs           # Symbol extraction from AST
│   └── context.rs           # Context-aware completion filtering
└── Cargo.toml

Key Design Principles

1. Single Source of Truth: All language metadata comes from shape-core
2. Performance: Document caching, efficient text operations with Rope
3. Robustness: Graceful degradation when parsing fails
4. Simplicity: Minimal code, maximum functionality

Protocol Support

Implements LSP specification with:

• Document synchronization (incremental)
• Diagnostics publishing
• Completion (with trigger characters: ., (, )
• Hover
• Signature Help (triggers: (, ,)
• Go-to-Definition
• Find References
• Document Symbols
• Workspace Symbols

License

MIT OR Apache-2.0

Contributing

The LSP queries shape-core/metadata.rs for all language information. To add new built-in functions or keywords, update the metadata API - the LSP will automatically pick them up.