MainAnnotation

MainAnnotation provides the functionality for a compiler-generated main class. It links a compiler-generated main method (call it compiler-main) to a user written main method (user-main). The protocol of calls from compiler-main is as follows:

• create a command with the command line arguments,

• for each parameter of user-main, a call to command.argGetter, or command.varargGetter if is a final varargs parameter,

• a call to command.run with the closure of user-main applied to all arguments.

Example: scala sc:nocompile /** Sum all the numbers * * @param first Fist number to sum * @param rest The rest of the numbers to sum */ @myMain def sum(first: Int, second: Int = 0, rest: Int*): Int = first + second + rest.sum generates scala sc:nocompile object foo { def main(args: Array[String]): Unit = { val mainAnnot = new myMain() val info = new Info( name = "foo.main", documentation = "Sum all the numbers", parameters = Seq( new Parameter("first", "scala.Int", hasDefault=false, isVarargs=false, "Fist number to sum"), new Parameter("rest", "scala.Int" , hasDefault=false, isVarargs=true, "The rest of the numbers to sum") ) ) val mainArgsOpt = mainAnnot.command(info, args) if mainArgsOpt.isDefined then val mainArgs = mainArgsOpt.get val args0 = mainAnnot.argGetter[Int](info.parameters(0), mainArgs(0), None) // using parser Int val args1 = mainAnnot.argGetter[Int](info.parameters(1), mainArgs(1), Some(() => sum$default$1())) // using parser Int val args2 = mainAnnot.varargGetter[Int](info.parameters(2), mainArgs.drop(2)) // using parser Int mainAnnot.run(() => sum(args0(), args1(), args2()*)) } }