`Box` is a text-based visual programming language inspired by Unreal Engine blueprint function graphs. ```console $ cat factorial.box ┌─ƒ(Factorial)───┐ ┌─[Branch]─────┐ ┌─[Set]─┐ │ ►┼─────────────────────┼► True ►┼───────────────────────┼► ►┼─────────┐ ┌─[For Loop]───────────┐ ┌───────┐ │ n ○┼──┐ ┌──┼○ False ►┼──┐ ┌──────────┐ ┌───┼○ │ └─────────┼► Loop body ►┼───────────────────┼► │ └────────────────┘ │ ┌────────┐ │ │ │ │ │ result ○┼──┘ ┌─┼○ │ │ │ ┌──────────┐ ┌────┼○ *= │ ┌────┐ └────┼○ >= ○┼─┘ └──────────────┘ │ └──────────┘ │ └───────┘ ┌────┐ │ │ │ result ○┼─┘ ┌─┼○ │ │ 1 ○┼───────┼○ │ │ ┌────┐ │ │ 1 ○┼────┼○ start │ └──────────┘ │ └───────┘ └────┘ └────────┘ │ │ 1 ○┼─────┘ └────┘ │ │ │ │ └────┘ │ index ○┼─────────────────┘ │ ┌────┐ │ │ │ │ n ○┼─┐ ┌───────┐ │ │ │ └────┘ └──┼○ + │ │ │ │ ┌────┐ ┌──┼○ ○┼─────┼○ end │ │ │ 1 ○┼─┘ └───────┘ │ │ │ └────┘ │ │ │ ┌────┐ │ │ │ ┌─[Return]─┐ │ 1 ○┼────┼○ step │ ┌────┐ └───┼► │ └────┘ │ Completed ►┼────┐ │ 1 ○┼─────┼○ │ └──────────────────────┘ │ ┌─[Return]─┐ └────┘ └──────────┘ ┌─────────┐ └──┼► │ │ result ○┼──────┼○ │ └─────────┘ └──────────┘ $ box factorial.box -e 5 120 $ box factorial.box -o factorial.py $ cat factorial.py def Factorial(n): if (n >= 1): result = 1 for index_8b6ee4f2 in range(1, (n + 1), 1): result *= index_8b6ee4f2 return result else: return 1 ``` ### Getting Started Install the box interpreter with `pip` ```console pip3 install boxlang ``` Now open your text editor and start drawing your program! Check out existing samples [here](https://github.com/p-ranav/box/tree/main/samples). ### Anatomy of a Box A Box has 2 types of ports: control flow ports (`─►┼─`) and data flow ports (`─○┼─`). These ports can additionally be classified as input or output ports. All ports to the left side of a box are input ports and all ports on the right side of the box are output ports. Below, you can see a `[For Loop]` box which is a special type of box that the interpreter can parse - It has 1 input control flow port, 3 input data flow ports (start, end, and step), 2 output control flow ports (the loop body and completed control flows), and 1 output data flow port (the index) ![image](https://user-images.githubusercontent.com/8450091/124202730-a69f1c80-daa0-11eb-8cd8-55a8447dc224.png) ### Function Graphs `Box` programs are function graphs. Functions have a single entry point designated by a node with the name of the Function containing a single output control flow port. Here's a simple hello world example. This example declares a `Greet()` function that prints the string "Hello, World!" to the console. It calls the built-in print function. ![image](https://user-images.githubusercontent.com/8450091/124202751-b28ade80-daa0-11eb-8be6-6d5157eed822.png) Execute the above program with the box interpreter like so: ```console $ box samples/hello_world.box -e Hello,World! ``` ### Features * ✅ Function declarations * ✅ Defining constants and variables * ✅ Operators - Unary, binary, and assignment operators * ✅ `[Set]` - set the value of variables * ✅ Function calls - Call Python built-in functions * ✅ `[Branch]` - if-else box * ✅ `[For Loop]` - Python-style for loop with (start,end,step) * ✅ `[While Loop]` - Python-style while loop * ✅ `[For Each]` for iterables * ✅ `[Break]` and `[Continue]` boxes * ✅ `[Return]` box to return values from functions ### Gotchas * The interpreter will likely fail if you have tabs in your file - replace all tabs with the appropriate number of spaces * There are a number of UNICODE character you'll need for this to work - Just look through the samples and COPY-PASTE (no, seriously) ## Contributing Contributions are welcome, have a look at the [CONTRIBUTING.md](https://github.com/p-ranav/box/blob/main/CONTRIBUTING.md) document for more information. ## License The project is available under the [MIT](https://opensource.org/licenses/MIT) license.