# Pluto
**Pluto** is an interpreted programming language implemented in Rust. It features a simple syntax, variable declarations, arithmetic expressions, string, float, and boolean support, function calls, method calls, member access, and more. Pluto is designed for learning and experimentation.
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## Features
| Variables | `let` keyword for variable declaration |
| Arithmetic Expressions | Supports `+`, `-`, `*`, `/` |
| Floating Point Support | Both integers and floats supported |
| String Support | String literals and concatenation |
| Boolean Support | `true` and `false` literals, type detection |
| Function Calls | Built-in functions like `print`, `type` |
| Method Calls | Call methods on strings, numbers, modules |
| Member Access | Access module members (e.g. `Math.pi`) |
| If Statements | Conditional execution with `if` and `else` |
| Simple Syntax | Easy to read and write |
| Extensible | Add your own built-in functions in Rust |
---
## Example
Given the following Pluto code in `test.po`:
```pluto
let x = 5.5;
print(x + 5);
print(x);
let a = "Result: ";
print(a);
let a = a + x;
print(a);
let abc = true;
let def = false;
print(abc, def, type(abc));
if !(5 < 2) {
print("a");
} else {
print("b");
}
```
**Output:**
```
10.5
5.5
Result:
Result: 5.5
true false Bool
a
```
---
## Types
Pluto supports the following value types:
| Number | 64-bit signed integer | `let x = 42;` |
| Float | 64-bit floating point number | `let y = 3.14;` |
| String | UTF-8 string | `let s = "hi";` |
| Bool | Boolean (`true` or `false`) | `let b = true;` |
| Module | Built-in module (e.g. `Math`) | `Math.pi` |
| Function| Built-in function | `print(x);` |
You can check the type of any value using the `type` built-in function:
```pluto
let x = 5.5;
print(type(x)); // Output: Float
let b = true;
print(type(b)); // Output: Bool
let s = "hello";
print(type(s)); // Output: String
```
---
## Getting Started
### Prerequisites
- Rust (edition 2021 or later)
### Build
```sh
cargo build --release
```
### Run
```sh
cargo run test.po
```
Or, after building:
```sh
./target/release/pluto test.po
```
---
## Language Syntax
| Variable Declaration | `let x = 10;` | Declare variable `x` |
| Arithmetic | `let y = x * 2 + 3;` | Expressions with `+ - * /` |
| String Literal | `let s = "hello";` | String assignment |
| String Concatenation | `let t = s + " world";` | Concatenate strings |
| Boolean Literal | `let b = true;` | Boolean assignment |
| Function Call | `print(y);` | Call built-in function |
| Float Support | `let z = 3.14;` | Floating point numbers |
| If Statement | `if x > 0 { print(x); }` | Conditional execution |
| Member Access | `Math.pi` | Access module member |
| Method Call | `"abc".len()` | Call method on value |
---
## Built-in Functions & Methods
| print | Prints arguments to stdout | `print(x);` |
| type | Returns the type of the argument | `print(type(x));` |
| Math.pi | Returns the value of π | `print(Math.pi);` |
| Math.pow(a,b) | Raises `a` to the power of `b` | `print(Math.pow(2,3));`|
| str.len() | Returns string length | `"abc".len()` |
| str.to_upper() | Uppercase string | `"abc".to_upper()` |
| str.to_lower() | Lowercase string | `"ABC".to_lower()` |
| str.char_at(i) | Char at index `i` | `"abc".char_at(1)` |
| num.to_string() | Convert number/float to string | `x.to_string()` |
---
## Contributing
Pull requests and suggestions are welcome!
---
## License
See [LICENSE](LICENSE).
---