What is TSL? What 4GL is it similar too?

TSL and 4GL are two major languages that are coming in to the scenario of the present world programming languages. What do you mean by a test script actually? 

Test scripts form a set of instructions that in turn can be performed on some software system or application under test for checking whether or not the functions are giving the desired output i.e., if they are working properly or not. There are two ways via which these test scripts can be executed as mentioned below:

1. Manual testing and
2. Automated testing

In this article we shall discuss regarding the test script language or TSL and fourth generation language or 4GL. First let us start our discussion with the test script language. 

About Test Script Language

- The Test script language lies at the heart of the integrated testing environment created by the mercury interactive.

- Test script language is categorized under the category of high level languages. 

- Its usefulness is born out of the combination of the flexibility as well as the power of the conventional programming languages and functions that have been developed as a tool or a feature to be used along with the products of the mercury interactive like winrunner and test director. 

- Also, this feature of the test script language has made it to be used for the modification and programming of the sophisticated test suites. 

- The functions that the test script language provides have been grouped in to the following four categories:

1. Analog functions
2. Context sensitive functions
3. Customization functions and
4. Standard functions.

- All of the above mentioned functions do not come with all the mercury interactive products. 

- Winrunner is one such mercury interactive product which supports all of these functions. 

- Apart from just the built in functions the test script languages gives its users the provision of creating their own functions.

What are Fourth Generation Languages - 4GL?

- A fourth generation programming language needs not necessarily be a language only it can also be a programming environment. 

- The 4GLs have been developed with a certain set of design patterns in mind and are assigned a specific problem domain. 

- 4GLs were developed as a succession to the 3GLs and are known to define a higher trend of statement power as well as abstraction. 

- It was observed that the 3GL languages were quite slow and much prone to errors. 

- As a result of the efforts to overcome this problem, the 4GL languages were born and these were more focussed towards aspects like:

     1. Systems engineering

     2. Problem solving and so on.

- The fourth generation language was designed as such that they cut down on the following: 

     1. programming efforts,

     2. Time consumed in development and of course

     3. The cost of the software development.

- However, in some of the cases, a try at achieving all this resulted in an ineffective and unmanageable code. 

- A formal definition of the 4GL was given by John Capers in terms of developer productivity (i.e., in terms of function points per staff month). 

- 4GL languages are said to support 12- 20 function points per staff month. 

- The 4GLs are a subset of domain specific programming languages has been stated a number of times by some researchers. 

- 4GLs have been classified in to 4 types as stated below:

1.Table driven programming (codeless): Uses table driven algorithm. Example: power builder.

2. Report generator programming languages: Generates the required report.

3. Fourth generation environments or more ambitious 4GLs: Specialize in generation whole system from output of CASE tools.

4. Data management 4GLs: such as-

             a)   SPSS

             b)   SAS

             c)   Stata