Eagle

A compiled language that is halfway between C and Go/Swift/Rust

Eagle is under active and heavy development; old code may break, but the programs in the example folder will always compile.

Pre-Built Binaries

Pre-built binaries for Linux and Mac are made available through the releases section of this repository.

Some Quick Examples

• Simple hello world

func main()
{
    puts 'Hello, world!'
}

• Generators and loops

gen range(int max) : int
{
    for int i = 0; i < max; i += 1
    {
        yield i
    }
}

func main()
{
    for int i in range(10)
    {
        puts i
    }
}

• Reference counting

func main()
{
    var i = new int(5) -- Allocate new integer
    puts i! -- Dereference the pointer
} -- Memory automatically freed

• Closures

func main()
{
    var i = 0
    var closure = func() {
        i += 2
    }

    closure()
    closure()

    puts i -- Prints '4'
}

Project Status

Working	Incomplete	Buggy	Not Working
Code compilation	32-bit code generation	Reference counting in class contexts	Nested generators
Basic reference counting	Static variables	Counted variables in loops	Reference counting in generators
Multiple file compilation	Imports and exports		Debug information
Control flow (if/elif/else, for, etc)	Type system
Optimization (with levels)	C-ABI compatibility (no passing structs by value)
Functions, closures, generators	Errors and warnings
Object orientation (classes, interfaces, views)	Generics
Linking, both other object files and libraries
Type inference
Semicolon injection

Principles

• Low level—no kid gloves
• Opt-in reference counting
• (Basic) opt-in object-oriented functionality
• High level features
• Modern syntax

Compiling

Prerequisites

You will need a development version of LLVM with version number >= 3.5 (i.e. the LLVM headers and associated helper programs like llvm-config). The process of getting LLVM will depend on your particular system.

You will also need a C compiler, a C++ compiler, make, and GNU Bison and Flex. LLVM also requires libzip, curses, and pthreads.

The compiler should compile under Linux and OS X. OS X El Capitan, Arch Linux, and Ubuntu have all been tested. Please note that, under Ubuntu installations (and likely other Linux systems), there may be multiple versions of LLVM in the repositories. Make sure to choose the newest one possible; the default will likely be relatively old and therefore unusable.

Build

As of the current versions of the compiler, users should use the standard UNIX build incantation:

• cd to build folder
• Run ./configure [--enable-debug]
• Run make There is currently no make install ... the compiler is far too unstable to think about installing it in the standard system. I have merely added the repository directory to my PATH.

At this point you will have a binary called eagle which will take code files as input.

Running

The latest version of the compiler can accept multiple input files. There are a variety of command line switches, which generally mirror the standard GNU gcc switches. The compiler currently supports exporting executables, object files (through -c), and assembly files. All output has an optional optimization pass, defined through -O0 ... -O3. Only files ending in ".egl" will be compiled.

The reference counting runtime support code is built in to the compiler (the code is copied from rc.egl at configure time). Thus there is no need to carry around that file or any object files (as in previous versions). To omit the resource counted module headers, use the command switch --no-rc. Output filename can be chosen with -o [filename]. See src/core/main.c to see a full listing of available commands.

If you are using the makefile associated with the project, there is a shortcut for building examples. Any code file in the examples folder can be compiled using make <name-of-file> omitting the .egl suffix. Alternatively you can run make all-examples to compile every example in the examples folder. The resulting binaries will be put in a folder called builtex. All of the built examples can be removed using make clean-examples. The more complex "Boggle" example has its own makefile which will work if the eagle executable exists in the main project directory.

Command Line switches

Argument	Action
[filename].egl	File will be compiled
-o [output name]	Specify binary output
-c	Generate object files from inputs
-S	Generate assembly code from inputs
-O[0-3]	Specify optimization level (default 2)
--no-rc	Do not include reference counting headers
--code [extra eagle code]	Specify extra code to compile from command line
-l[libname]	Link external library
-L[libpath]	Add linker search path
--llvm	Dump llvm bitcode
--verbose	Provide details of compilation process
--threads [thread-count]	Specify number of threads to use during code generation