Tag:Type information

  • Python naming conventions

    Time:2022-1-12

    variable Generally all lowercase _ Underline segmentation Private variable_ Begin with an underscore Name without type information num_ list name = ‘jeck’ student_name = ‘cc’ for _i in range(10): pass constant uppercase _ Underline segmentation MAX_COUNT = 10 function All lowercase _ Underline segmentation Private function_ Begin with an underscore def call(): pass def call_name(): […]

  • [Flink] source code Notes – datastream and transformation

    Time:2021-12-23

    DataStream A DataStream represents a stream of elements of the same type. A DataStream can be transformed into another DataStream by applying a transformation. Datastream is a user oriented API encapsulation of data stream. The bottom layer is actually a tranformation chain. Datastream continues to add tranformation to the internal tranformation chain through methods such […]

  • [calculate] interpretation of Apache calculate verification process source code

    Time:2021-12-16

    1. Core structure and concept The validator process provided by calculate is extremely complex, but in summary, it mainly does one thing,Verify whether the semantics of each sqlnode is correct by combining metadata, these semantics include: Verify whether the table name exists; Whether the selected column exists in the corresponding table and whether the matched […]

  • Let’s talk about the allowed lateness of Flink

    Time:2021-10-2

    order This paper mainly studies the allowed lateness of Flink WindowedStream flink-streaming-java_2.11-1.7.0-sources.jar!/org/apache/flink/streaming/api/datastream/WindowedStream.java @Public public class WindowedStream<T, K, W extends Window> { /** The keyed data stream that is windowed by this stream. */ private final KeyedStream<T, K> input; /** The window assigner. */ private final WindowAssigner<? super T, W> windowAssigner; /** The trigger that is […]

  • Learn go and rust through examples

    Time:2021-7-5

    Pointer indicates the location, length and type of a piece of data in memory. You can operate pointers in go and rust. Let’s take a simple example to see their similarities and differences. Go func zeroval(ival int) { ival = 0 } func zeroptr(iptr *int) { *iptr = 0 } func main() { i := […]

  • How to use type command in Linux system

    Time:2021-4-13

    typeTools for displayingcommandType information for. It will be shown on thecommandEnter how the given command will be interpreted on the line. How to use the type command typeThe command is built-in to bash, and the type syntax is as follows: type [-afptP] [name …] For example, viewtypeThe type of [[email protected] ~]# type typetype is a […]

  • Java Basics: a deep understanding of generics

    Time:2021-2-19

    1. Java generics 2. How to implement Java generics? Java generics are implemented throughType Erasure It’s true! That is, Java generics are pseudo generics. During compilation, all generics information will be erased. Therefore, the java compiler will find possible errors as much as possible at compile time, but it still can’t find the type conversion […]

  • Flink Learning Series — basic knowledge learning (4)

    Time:2020-1-11

    Preface This lecture will introduce the serialization mechanism and process function. Serialization mechanism When writing processing logic with Flink, novices are always confused by a myriad of concepts: Why does Flink have so many type declarations? What’s the difference between basictypeinfo. String? Type? Info, types. String, types. String()? What is typeinfofactory? How are typeinformation.of and […]