RETR
Takes the topmost item from the stack as a key and looks up its value in the database.
Input stack: key
Output stack: value
This is one of the ways to read data from the database. Only valid within WRITE's or READ's scopes. Can only be used to retrieve keys that were used.
PumpkinDB> "hi" [ASSOC?] READ
Allocation
None
Errors
EmptyStack error if there are less than two items on the stack
NoTransaction error if there's no current write transaction
UnknownKey error if there is no such key. See ASSOC? for mediating this problem
Tests
works : "hi" "there" 2DUP [ASSOC COMMIT] WRITE SWAP [RETR] READ EQUAL?.
requires_txn : ["hi" RETR] TRY UNWRAP 0x08 EQUAL?.
empty_stack : [RETR] TRY UNWRAP 0x04 EQUAL?.