Script file

Swag can be used to build and run a simple script file, thanks to the fact that the compiler can run anything at compile time. No executable will be generated, the compiler will do all the job. To create a new script file with the special extension swgs:

$ swag new -f:myScript
=> script file 'myScript.swgs' has been created
=> type 'swag script -f:myScript.swgs' to run that script

This will generate a simple file with a #dependency block and the program entry point #main.

// Swag script file
#dependencies
{
    // Here you can add your external dependencies
    // #import "core" location="swag@std"
}

#main
{
    @print("Hello world !\n")
}

You can then run your script with the script command.

$ swag script -f:myScript
Hello world !

You can also just specify the script file with the extension as a command.

$ swag myScript.swgs
Hello world !

As examples, you will find a bunch of small scripts in swag/bin/examples/scripts. To run one of them from the console, go to the folder and type for example swag flappy.swgs.

Flappy Bird

Dependencies

You can add external dependencies, and they will be compiled and used as native code.

#dependencies
{
    // Import the standard module `core` from the swag standard workspace (which comes with the compiler)
    #import "core" location="swag@std"
}

A special hidden workspace (in the Swag cache folder) will be created to contain all the corresponding native code.

To locate the Swag cache folder, add --verbose-path to the command line.
To force the build of dependencies, add --rebuildall to the command line.

More than one script file

If your script is divided in more than one single file, you can add #load <filename> in the #dependencies block.

#dependencies
{
    #load "myOtherFile.swgs"
    #load "folder/myOtherOtherFile.swgs"
}

Debug

The compiler comes with a bytecode debugger that can be used to trace and debug compile time execution. Add @breakpoint() in your code when you want the debugger to trigger.

The debugger command set is inspired by Pdb, the python debugger.

Generated on 08-09-2024 with swag 0.40.0