---
title: Flox
date: 2024-08-25T09:59:41Z
desc: >
    Small functional language written in Rust and compiled to WebAssembly
---

## Grammar

```
Program      ::= Sequence "EOF"
Sequence     ::= Expression? (";" Expression)*

Expression   ::= Data 
               | Match 
               | Let 
               | If 
               | While 
               | Return 
               | Block 
               | Assignment

Data         ::= "data" IDENTIFIER ("|" IDENTIFIER (IDENTIFIER)*)*
Match        ::= "match" Expression ( "|" Expression IDENTIFIER* "->" Expression )*
Let          ::= "let" IDENTIFIER (IDENTIFIER)* "=" Expression
If           ::= "if" Expression Expression ("else" Expression)?
While        ::= "while" Expression Expression
Return       ::= "return" Expression?
Block        ::= "{" Sequence "}"
Assignment   ::= Call ("=" Assignment)?
Call         ::= Index (Index)*
Index        ::= Primary ("." IDENTIFIER)?

Primary      ::= IDENTIFIER 
               | NUMBER 
               | STRING 
               | "true" 
               | "false" 
               | "nil" 
               | Lambda 
               | Parenthesized 
               | Array

Lambda       ::= "fn" IDENTIFIER+ "->" Expression
Parenthesized ::= "(" (Expression ("," Expression)*)? ")"
Array        ::= "[" (Expression ("," Expression)*)? "]"
Arguments    ::= "(" (Expression ("," Expression)*)? ")"
```