Compiler main method should return error codes

[tilm4nn]

As a Java software developer when compiling jnario files with gradle using the main method org.jnario.compiler.CompilerMain I would like grade to stop the build if the compilation fails.

To enable that gradle should be able to recognize the outcome of the compilation. This can be done by changing the

public static void main(String[] args)

to

public static int main(String[] args)

and returning 0 if the compilation succeeds and an error code other than 0 when the compilation fails.