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: * Lightweight: A well-optimized interpreter with very little resources. Ideal for use in microprocessors. * Fast: optimized one-pass bytecode compiler and register-based virtual machine. * Powerful: supports imperative programming, object-oriented programming, functional programming. * Flexible: Berry is a dynamic type script, and it's intended for embedding in applications. It can provide good dynamic scalability for the host system. * Simple: simple and natural syntax, support garbage collection, and easy to use FFI (foreign function interface). * RAM saving: With compile-time object construction, most of the constant objects are stored in read-only code data segments, so the RAM usage of the interpreter is very low when it starts. ## Documents Reference Manual: [Wiki](https://github.com/berry-lang/berry/wiki/Reference) Short Manual (slightly outdated): [berry_short_manual.pdf](https://github.com/Skiars/berry_doc/releases/download/latest/berry_short_manual.pdf). Berry's EBNF grammar definition: [tools/grammar/berry.ebnf](./tools/grammar/berry.ebnf) ## Features * Base Type * Nil: `nil` * Boolean: `true` and `false` * Numerical: Integer (`int`) and Real (`real`) * String: Single quotation-mark string and double quotation-mark string * Class: Instance template, read only * Instance: Object constructed by class * Module: Read-write key-value pair table * List: Ordered container, like `[1, 2, 3]` * Map: Hash Map container, like `{ 'a': 1, 2: 3, 'map': {} }` * Range: include a lower and a upper integer value, like `0..5` * Operator and Expression * Assign operator: `=`, `+=`, `-=`, `*=`, `/=`, `%=`, `&=`, `|=`, `^=`, `<<=`, `>>=` * Relational operator: `<`, `<=`, `==`, `!=`, `>`, `>=` * Logic operator: `&&`, `||`, `!` * Arithmetic operator: `+`, `-`, `*`, `/`, `%` * Bitwise operator: `&`, `|`, `~`, `^`, `<<`, `>>` * Field operator: `.` * Subscript operator: `[]` * Connect string operator: `+` * Conditional operator: `? :` * Brackets: `()` * Control Structure * Conditional statement: `if-else` * Iteration statement: `while` and `for` * Jump statement: `break` and `continue` * Function * Local variable and block scope * Return statement * Nested functions definition * Closure based on Upvalue * Anonymous function * Lambda expression * Class * Inheritance (only public single inheritance) * Method and Operator Overload * Constructor method * Destructive method * Module Management * Built-in module that takes almost no RAM * Extension module support: script module, bytecode file module and shared library (like *.so, *.dll) module * GC (Garbage collection) * Mark-Sweep GC * Exceptional Handling * Throw any exception value using the `raise` statement * Multiple catch mode * Bytecode file support * Export function to bytecode file * Load the bytecode file and execute ## Build and Run 1. Install the readline library (Windows does not need): ``` bash sudo apt install libreadline-dev # Ubuntu brew install readline # MacOS ``` 2. Build (The default compiler is GCC): ``` make ``` 3. Run: ``` bash ./berry # Bash or PowerShell berry # Windows CMD ``` 4. Install (Only Unix-like): ``` bash make install ``` ## Editor plugins [Visual Studio Code](https://code.visualstudio.com/) plugin are in this directory: [./tools/plugins/vscode](./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: ``` lua print("Hello world!") ``` You will see this output: ``` Hello world! ``` You can copy this code to the REPL: ``` ruby 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: ``` bash ./berry test.be ``` This will also get the correct output. ## License Berry is free software distributed under the [MIT license](./LICENSE). The Berry interpreter partly referred to [Lua](http://www.lua.org/)'s design. View Lua's license here: http://www.lua.org/license.html.