mostly finish documenting Proc::Async

lib/Type/Proc/Async.pod

@@ -132,10 +132,56 @@ L<X::Proc::Async::OpenForWriting> exception will the thrown.
 C<start> must have been called before calling method write, otherwise an
 L<X::Proc::Async::MustBeStarted> exception is thrown.
 
-=begin comment
+=head2 method print
 
-TODO: various exceptions, print, say, close-stdin, kill
+    method print(Proc::Async:D: Str(Any) $str, :$scheduler = $*SCHEDULER)
 
-=end comment
+Write the text data in C<$str> to the standard input stream of the external
+program, encoding it as UTF-8.
+
+The C<Proc::Async> object must be created for writing (with
+C<Proc::Async.new(:w, $path, @args)>). Otherwise an
+L<X::Proc::Async::OpenForWriting> exception will the thrown.
+
+C<start> must have been called before calling method print, otherwise an
+L<X::Proc::Async::MustBeStarted> exception is thrown.
+
+=head2 method say
+
+    method say(Proc::Async:D: Str(Any) $str, :$scheduler = $*SCHEDULER)
+
+Write the text data in C<$str> and a newline to the standard input stream of the external
+program, encoding it as UTF-8.
+
+The C<Proc::Async> object must be created for writing (with
+C<Proc::Async.new(:w, $path, @args)>). Otherwise an
+L<X::Proc::Async::OpenForWriting> exception will the thrown.
+
+C<start> must have been called before calling method say, otherwise an
+L<X::Proc::Async::MustBeStarted> exception is thrown.
+
+=head2 method close-stdin
+
+    method close-stdin(Proc::Async:D:)
+
+Closes the standard input stream of the external program. Programs that read
+from STDIN often only terminate when their input straem is closed. so if
+waiting for the promise from C<#method start> hangs (for a program opened for
+writing), it might be a forgotten C<close-stdin>.
+
+The C<Proc::Async> object must be created for writing (with
+C<Proc::Async.new(:w, $path, @args)>). Otherwise an
+L<X::Proc::Async::OpenForWriting> exception will the thrown.
+
+C<start> must have been called before calling method close-stdin, otherwise an
+L<X::Proc::Async::MustBeStarted> exception is thrown.
+
+=head2 method kill
+
+    kill(Proc::Async:D: $signal = "HUP")
+
+Sends a signal to the running program. The signal cann be a signal name
+("KILL" or "SIGKILL"), an integer (9) or an element of the C<Signal> enum
+(Signal::SIGKILL).
 
 =end pod