CURSOR/NEXT
Sets the cursor at the next key value
Input stack: cursor
Output stack: b
If there is a next key/value pair in the database, 1 will be pushed onto the stack and the cursor will be moved.
Otherwise, 0 will be pushed and the cursor will not be moved.
Useful in conjunction with CURSOR/CUR
PumpkinDB> ["1" "2" ASSOC "2" "2" ASSOC COMMIT] WRITE [CURSOR DUP CURSOR/FIRST DROP DUP CURSOR/NEXT DROP CURSOR/KEY] READ
"2"
Allocation
Allocates for values to be put onto the stack
Errors
NoTransaction error if there's no current write transaction
InvalidValue error if the cursor identifier is incorrect or expired
Tests
works : ["1" "2" ASSOC "2" "2" ASSOC COMMIT] WRITE [CURSOR DUP CURSOR/FIRST SWAP CURSOR/NEXT AND] READ.
end : ["1" "2" ASSOC "2" "2" ASSOC COMMIT] WRITE [CURSOR DUP CURSOR/LAST SWAP CURSOR/NEXT NOT AND] READ.
requires_txn : ["1" CURSOR/NEXT] TRY UNWRAP 0x08 EQUAL?.
empty_stack : [[CURSOR/NEXT] TRY] READ UNWRAP 0x04 EQUAL?.
invalid_cursor : [["1" CURSOR/NEXT] READ] TRY UNWRAP 0x03 EQUAL?.