readNext

ReadNext is a term used in computing to denote a function, method, or operation that retrieves the next item from a sequence, cursor, or input stream. The concept is common across programming languages, database tools, and data processing libraries, and it generally serves as an abstraction for advancing to the subsequent element.

In database shells and similar interactive environments, readNext often refers to a helper that fetches the next document or record from an active cursor. Each invocation advances the cursor and returns the next item, or a sentinel value such as null or undefined when the end of the data is reached. This pattern supports lightweight loops and ad hoc data exploration in environments like shell interfaces.

In programming libraries, readNext may be used as an alias or variant of more common iteration methods such as next() or moveNext(). The exact behavior—whether it is synchronous or asynchronous—depends on the language and library. In asynchronous contexts, readNext might return a promise or require a callback, while in synchronous contexts it typically returns the next element directly.

In streaming and I/O contexts, readNext can refer to reading the next line, token, or data chunk from an input source. Such implementations must handle end-of-stream conditions, buffering, and potential errors, and may offer non-blocking or blocking variants.

Common characteristics across implementations include advancing an internal position, returning the next element, and signaling completion when no more items are available. Developers should consult the specific library or environment documentation for exact semantics, error handling, and performance considerations.

See also: next, iterator, cursor, stream, read, fetch.