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The Lagoon Language
Lagoon is a dynamic, weakly-typed and minimal scripting language. It draws inspiration from a handful of modern languages including JavaScript, Rust and PHP.
If you want to learn more about the language itself, you can read the SPECIFICATION or take a look at the collection of examples in this repository.
Example
-- This is a recursive fibonacci function. It accepts a number `n`.
fn fib(n) {
if n < 2 {
return n
}
return fib(n - 1) + fib(n - 2)
}
println(fib(10)) -- `println` is a function in the standard library.
Theory
Lagoon parses a string of source code into a token stream and abstract syntax tree (AST).
The generated AST is then passed to an interpreter. It uses a tree-walk approach to recursively iterate through each node in the tree.
A tree-walk interpreter is one of the slowest methods of execution, but it's also one of the simplest. In the future Lagoon will likely move to a bytecode interpreter but whilst the language itself is still in early development, a tree-walk interpreter will continue to be used.
At the highest level, all operations in Lagoon are parsed as statements. A statement can contain one or more expressions. Those expressions are generally used to manipulate the execution environment and provide information to your script.
Development Checklist
Lagoon is nowhere near being feature complete or syntax complete. Below is a small checklist of things that we still need to add and design before marking it as "stable".
-
&&
,||
- Boolean infix operators -
>
,>=
,<
,<=
- Mathematical comparison operators -
**
- Exponent / power operator -
&
,|
,^
,~
,<<
,>>
- Bitwise operators - Lists
-
for..in
statements -
in
,not in
operators - Scalar objects (methods on scalar types)
- Module system
- Standard Library
- Nicer error reporting
- Transpile to JavaScript
- Nicer command-line interface
- Constant declarations (
const
) - Migrate parser to on-demand token stream
- Line/column numbers in errors
- Build a virtual machine to replace the interpreter
Contributing
If you would like to contribute to Lagoon, please feel free to fork this repository and open a pull request. All contributions are highly appreciated, no matter your Rust knowledge.