Open a connection to a file or process

hopen filehandle
hopen processhandle
hopen (communicationhandle;timeout)
hopen port

Where

conencts to a file object or a communication handle, and returns a connection handle as an int.

hopen ":path/to/file.txt"                   / filehandle
hopen `:unix://5010                         / localhost, Unix domain socket
hopen(":10.43.23.198:5010";10000)           / IP address and timeout
hopen 5010                                  / local port number

For IPC compatibility, it serializes to {hopen x}. e.g.

hopen each(`:mysymbol;
        ":mycharvector";
        `:localhost:5000;
        ":localhost:5000";
        (`:localhost:5000;1000);
        (":localhost:5000";1000))