LamPlus Language Extension

A Visual Studio Code extension providing syntax highlighting and language support for the LamPlus functional programming language.

Features

Syntax Highlighting: Full syntax highlighting for LamPlus language constructs
Auto-completion: Bracket and quote auto-completion
Comment Support: Line comments using #
Code Folding: Support for folding code blocks
File Extensions: Supports .lam and .lamp files

Language Features

LamPlus is a functional programming language with the following key features:

Keywords

Definitions: def, fail, type, rec, effect
Control Flow: main, let, in, switch, on, match, with, handle, return
Lambda: \ (backslash for lambda expressions)

Types

Function Types: A -> B
Effect Types: A ~> B
Sum Types: + {'label1: Type1, 'label2: Type2}
Product Types: (Type1, Type2, Type3)
Type Parameters: Type[T1, T2]

Identifiers

Global Types/Functions: Start with uppercase letter (e.g., List, Option)
Local Variables: Start with lowercase letter or underscore (e.g., x, _temp)
Effects: Start with $ (e.g., $Console, $IO)
Labels: Start with ' (e.g., 'some, 'none)

Operators

->: Function type arrow
~>: Effect type arrow
<~: Resume operator
=: Assignment
:: Type annotation
|: Pattern alternative
+: Sum type constructor

Example Code

# Type definitions
type Option[T] = + {'some: T, 'none: ()}
type List[T] = + {'cons: (T, List[T]), 'nil: ()}

# Effect definition
effect $Console: String ~> ()

# Function definition
def map[A, B]: (A -> B, List[A]) -> List[B] = 
  \f. \lst. 
    match lst with {
      'nil x: 'nil (),
      'cons (head, tail): 'cons (f head, map f tail)
    }

# Main function with effects
main: () = 
  let numbers: List[Int] = 'cons (1, 'cons (2, 'nil ())) in
  handle 
    $Console "Hello, LamPlus!"
  with {
    $Console msg k: 
      let () = print msg in k (),
    return x: x
  }

Installation

Download and install the extension from the VS Code Marketplace
Open any .lam or .lamp file to see syntax highlighting in action

Development

To develop this extension:

Clone this repository
Open in VS Code
Press F5 to open a new Extension Development Host window
Open a .lam file to test the syntax highlighting

Language Grammar

This extension is based on a Lark parser grammar that defines the complete syntax of the LamPlus language. The TextMate grammar provides syntax highlighting for:

Keywords and control structures
Type definitions and annotations
Function definitions and lambda expressions
Pattern matching constructs
Effect definitions and handlers
Comments and documentation

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

License

MIT License - see LICENSE file for details.

LamPlus

jiamingshan