SUBSCRIBE
Subscribes the connection to a topic
Input stack: topic
Output stack: subscription
SUBSCRIBE allows connected client to subscribe any message topic
on the server. Pushes subscription identifier back to the top of the stack.
PumpkinDB> "topic" SUBSCRIBE
0xea60d7d866144e0184ac8c9b462d0737
Allocation
Runtime allocations necessary for the server
Errors
EmptyStack error if there is less than one item on the stack
Tests
empty_stack : [SUBSCRIBE] TRY UNWRAP 0x04 EQUAL?.