Incan Language Server (LSP)¶

The Incan Language Server provides IDE integration for real-time feedback while coding.

Features¶

Feature	Description
Diagnostics	Real-time errors, warnings, and hints as you type
Hover	View function signatures, types, and documentation
Go-to-Definition	Jump to symbol definitions (Cmd/Ctrl + Click)
Completions	Autocomplete for keywords and symbols

Installation¶

1. Build the LSP Server¶

cd /path/to/incan-programming-language
make lsp

2. Add to PATH¶

Add the binary to your PATH:

# Add to .bashrc, .zshrc, or your shell profile
export PATH="$PATH:/path/to/incan-programming-language/target/release"

Or symlink it:

sudo ln -s /path/to/incan-programming-language/target/release/incan-lsp /usr/local/bin/

3. Install VS Code Extension¶

See Editor Setup for VS Code/Cursor extension installation.

Usage¶

Once installed, the LSP activates automatically when you open .incn files.

Real-time Diagnostics¶

Errors appear as you type with helpful hints:

type error: Type mismatch: expected 'Result[str, str]', found 'str'
  --> file.incn:8:5

note: In Incan, functions that can fail return Result[T, E]
hint: Wrap the value with Ok(...) to return success

Hover Information¶

Hover over any symbol to see its type:

def process(data: List[str]) -> Result[int, Error]

Go-to-Definition¶

VS Code/Cursor: Cmd+Click (macOS) or Ctrl+Click (Windows/Linux)
Keyboard: F12 or Ctrl+Click

Works for:

Functions
Models
Classes
Traits
Enums
Newtypes

Completions¶

Trigger completions with Ctrl+Space or by typing:

. for field/method access
: for type annotations

Suggestions include:

Incan keywords (def, model, class, etc.)
Symbols from current file
Built-in types (Result, Option, etc.)

Configuration¶

VS Code Settings¶

{
  "incan.lsp.enabled": true,
  "incan.lsp.path": "/path/to/incan-lsp"
}

Setting	Default	Description
`incan.lsp.enabled`	`true`	Enable/disable the language server
`incan.lsp.path`	`""`	Custom path to incan-lsp (uses PATH if empty)

Troubleshooting¶

LSP Not Starting¶

Check binary exists:

which incan-lsp
# or
incan-lsp --version

Check VS Code output:
- View → Output → Select "Incan Language Server"
Verify extension is active:
- Extensions panel → Search "Incan" → Check it's enabled

No Diagnostics¶

Ensure the file has .incn extension
Check for syntax errors that prevent parsing
Try reloading the window (Cmd/Ctrl + Shift + P → "Reload Window")

Hover Not Working¶

LSP must successfully parse the file first
Check for diagnostics/errors in the file
Ensure cursor is on a symbol (function name, type name, etc.)