- mdb-cursor-get cursor key data opprocedure
Retrieve by cursor.
This procedure mostly follows the C API for mdb_cursor_get but does not modify the key and data paramters to return data - instead call (mdb-cursor-key) and (mdb-cursor-data) after this function to access the current key/data values for the cursor.
- cursor
- A cursor handle returned by (mdb-cursor-open)
- key
- The key to look up (if #f do not modify the cursors current key value)
- data
- The data to look up (useful for dupsort databases, if #f do not modify the cursors current value)
- op
- A cursor operation MDB_cursor_op (see Cursor Operatios in Constants)
- (exn lmdb MDB_NOTFOUND)
- no matching key found.
- (exn lmdb EINVAL)
- an invalid parameter was specified.