berry-lang / berry

A ultra-lightweight embedded scripting language optimized for microcontrollers.
https://berry-lang.github.io
MIT License
829 stars 97 forks source link
berry c embedded language microcontroller scripting-language

Berry

The Berry Script Language.

Introduction

Berry is a ultra-lightweight dynamically typed embedded scripting language. It is designed for lower-performance embedded devices. The Berry interpreter-core's code size is less than 40KiB and can run on less than 4KiB heap (on ARM Cortex M4 CPU, Thumb ISA and ARMCC compiler).

The interpreter of Berry include a one-pass compiler and register-based VM, all the code is written in ANSI C99. In Berry not every type is a class object. Some simple value types, such as int, real, boolean and string are not class object, but list, map and range are class object. This is a consideration about performance. Register-based VM is the same meaning as above.

Berry has the following advantages:

Documents

Reference Manual: Read the docs

Short Manual: berry_short_manual.pdf.

Berry's EBNF grammar definition: tools/grammar/berry.ebnf

Features

Build and Run

  1. Install the readline library (Windows does not need):

    sudo apt install libreadline-dev # Ubuntu
    brew install readline            # MacOS
  2. Build (The default compiler is GCC):

    make
  3. Run:

    ./berry # Bash or PowerShell
    berry   # Windows CMD
  4. Install (Only Unix-like):

    make install

Editor plugins

Visual Studio Code plugin are in this directory: ./tools/plugins/vscode.

Examples

After compiling successfully, use the berry command with no parameters to enter the REPL environment:

Berry 0.0.1 (build in Dec 24 2018, 18:12:49)
[GCC 8.2.0] on Linux (default)
>

Now enter this code:

print("Hello world!")

You will see this output:

Hello world!

You can copy this code to the REPL:

def fib(x)
    if x <= 1
        return x
    end
    return fib(x - 1) + fib(x - 2)
end
fib(10)

This example code will output the result 55 and you can save the above code to a plain text file (eg test.be) and run this command:

./berry test.be

This will also get the correct output.

License

Berry is free software distributed under the MIT license.

The Berry interpreter partly referred to Lua's design. View Lua's license here: http://www.lua.org/license.html.