Bright box development

The bright box has not been allowed, and it is strictly forbidden to reprint this column. This Paper has been reproduced from the Software Engineering Expert Network www.21cmm.com. Do not reprint without CBS license, thank you for the cooperation (1) The mingbo box definition is defined. The process of converting the status cartridge function. The input, response set, and external behavior and state of the mandatory box and the corresponding state box are the same. The bright box process usually surrounds external services, and its users (people, hardware or other bright boxes) can call these services. For example: a data management bright box can provide services to join, delete, and retrieve user data. The focus of the bright box design is the development of the algorithm. The state cartridge specification that is implemented by the mating process constructed by the CASE statement can implement only a small algorithm detail. These statements detect current inputs and previous states for proper responses and generate new states. These processes are essentially equivalent to retrieving status cartridges for determining the correct transformation. Verification can also be accomplished by equivalent comparison of a separate status cartridge transformation with a partial implementation of a bright box statement. However, in a gently intensive system, the status cartridge specification requires an extended mandatory analysis, design, and correctness to verify that these systems may display simple status cartridge specification, which still need to be implemented in the form of a bright box. These willers usually lead to large process design, but also need to define new black boxes or useful black boxes. The bright box is composed of order, selection, and cyclic control structures. An example is shown in graphical and design language in Table 4.1 (Mills, Linger, and Hevner, 1986). It is also possible to introduce a parallel control structure. The control structure is composed of function nodes and determination nodes, and the function nodes are represented by g and h in the table, and the determination node is expressed. The gathering node represented by a circle aggregates the control flow. A functional node can represent any operations from the simplest assignment to complex calculations. Any function node itself can be a new or reused black box. Each function node in the bright box can use the current state as an input, or a new state can be generated as an output. Each determination node can be accessed but cannot change the current state. The sequential control structure can be extended to a plurality of functional nodes (Table 4.1 gives an example with two functional villages), or a function node to the index variable control under index variable control. Just like the structure of the Fordo. Iftfenelse can be considered a multi-branch Case structure. For ease of reference, each portion can be replaced by one name, such as the order, G, and H are the first portion and the second portion. In IFTHEN, P, g, and h indicate conditional tests, affirm the execution section, and negative execution portions. In WHILEDO, P and G indicate a circular condition test and execution section, respectively. Each bright box control structure has a single entrance line and a single export line, no side effects in the control flow. From the entrance line to the outlet, a control structure only performs the transformation of the data. Add as a single / single-out property, these control structures. Equivalent to mathematical functions. For example, the following is a three-step order assignment, the variable is t, x, y (: = equivalent to the teacher's value) DO T: = x: = y y: = t enddo As shown in the figure below. In Point1, a initialization definition domain defines the value of TXY (add 0 represents the initial value, if T0 is the initial value of T). The first step t: = x Improve the value of the value to x to implement X to Y teacher value in form POINT2, POINT3. Finally reached POINT4. The entire order of the sequence from 1 to 4 can be expressed by the natural language as: assigns an X, and the value of X, Y is exchanged. Alternatively, the parallel assignment: t, x, y: = x, y, x are assigned all variables or expressions of the value of the value of the value to the respective position at the same time in the parallel assignment value. That is, X to T, Y to XX to Y are typically typically.

The function definition is independent of the order with a collection representation, {(, )}. This definition is also unrelated to the context. Even in a large bright box, the function definition is also the same for any mile-box control structure, which implements mapping from the defined domain to the value domain like the example in Figure 4.2. (2) The abstraction and documentation of the bright box should be interpreted and understood in accordance with the impact of the control structure from the entrance to the export to the data, and document according to the form of function. The program function is defined as a function of the final value of the variable as the initial value, which is determined by the function abstraction. The defined way is widely used, from natural language to mathematical formulas. The program function is functional equivalent to the corresponding control structure. Systemically interpretation and abstract program logic helps to recover lost or incomplete documents. In particular, in the successive forms, the reuse of the reuse, it can be interpreted and abstracted to obtain design documents, which helps to restore the embedded transaction rules to eventually increase maintainability and scalability. For example, in the following table (WXY and Z are positive integers) lists the abstract results to interpret and analyze the control structure and their function functions. The program function of Sequence is a combination of individual operations. Here, the value of W obtained in the first step operation can replace W appear in the second portion. The ifthenenelse structure is to combine its true hypothesis as an expression. In this way, true and false operations can be seen as an universal mathematical operation. Whiledo and other loop structures may require more analysis, but usually combine the results of multiple cyclic execution of an expression. In this example, if x is odd, its value is reduced in each cycle until 1, and the loop is terminated. If it is even until 3 terminates. This program function can be conveniently represented by the following two conditional rules: (Condition1 → Rule1 | Condition2 → Rule2) Here, each condition is an assertion that defines the environment to determine whether to perform the corresponding rule (assignment). Vertical strip (|) represents "or". In this way, if the initial X is odd, it is the final value of 1. Otherwise, if the initial value of X is even, the final value is 0 (in general, the conditional rules can have multiple parts). If all conditions in the conditional rules are independent, this conditional rule is called an ineffective rule, and the order in which the conditions is arranged does not affect the results. Utty rules are useful when the program function is denoted. Note that a state box also defines an irregular rule that may contain many conditions, which evaluate the input and existing status to determine the output and new status. The program functions of the sepuence, ifthenelse, and the WHILEDO structure in the above table are the order, and the selection is independent, and the loop is independent. That is to say, the program functions of these structures will be abstract, only defined from the actual impact of the data to the export. The single-in-one single-out nature of the control structure and function node is critical to the abstraction, design and verification of the bright box. Therefore, the bright box design should avoid the use of specific statements that affect these properties (such as a GOTO statement that causes random branch logic). Single-in single-exiting structure allows you to perform well when you create a large design, there is a good scalability. Especially if you need to implement a status cartridge conversion function, you can continuously connect the control structure in order or nested methods in the bright box design. To illustrate this problem, consider the design of the bright box shown below. The bottom WHILE Q DO IENDDO located in the design, the actual effect of the entrance to the exit (NET Effect) can be abstract as a program function that is independent of the loop, named A. Do g; h Enddo is abstracted as a program function that is independent of the order, named B.