Brief history of computer programming languages

Read the following words and word combinations and use them for understanding and translation of the text:

to specify - уточнять

to morph into - трансформироваться в...

logical branching - логическое ветвление

tedious - утомительный

to affect - влиять

shared program - разделенная (совместно используемая) программа

hand-wired - установленный вручную

array - массив

explicit - точный

restrictive - ограничивающий

to handle - загружать, обрабатывать

to surpass - превосходить

parse tree - дерево синтаксического разбора

dynamic variable - динамическая переменная

to wind up - завершиться

to implement - внедрять

sequentially - последовательно

slider bar - скользящий маркер, бегунок

duct tape - скотч

oddball - эксцентричный

Ever since the invention of Charles Babbage’s difference engine in 1822, computers have required a means of instructing them to perform a specific task - a program. This means is known as a programming language. A programming language is a set of rules that specify which sequences of symbols constitute a program, and what computation the program describes.

A programming language is an abstraction mechanism. It enables a programmer to specify a computation abstractly, and to let a program (usually called an assembler, compiler or interpreter) implement the specification in the detailed form needed for execution on a computer. Programming languages are the medium of expression in the art of computer programming. An ideal programming language will make it easy for programmers to write programs clearly. Because programs are meant to be understood, modified, and maintained over their lifetime, a good programming language will help others read programs and understand how they work. In evaluating programming languages, we must consider the tasks of designing, implementing, testing, and maintaining software, asking how well each language supports each part of the software life cycle.

Computer languages were first composed of a series of steps to wire a particular program; these morphed into a series of steps keyed into the computer and then executed; later these languages acquired advanced features such as logical branching and object orientation. The computer languages of the last fifty years have come in two stages, the first major languages and the second major languages, which are in use today.

In the beginning, Charles Babbage’s difference engine could only be made to execute tasks by changing the gears which executed the calculations. Thus, the earliest form of a computer language was physical motion. Eventually, physical motion was replaced by electrical signals when the US Government built the ENIAC in 1942. It followed many of the same principles of Babbage’s engine and hence, could only be “programmed” by presetting switches and rewiring the entire system for each new “program” or calculation. This process proved to be very tedious.

In 1945, John Von Neumann was working at the Institute for Advanced Study. He developed two important concepts that directly affected the path of computer programming languages. The first was known as “shared-program technique”. This technique stated that the actual computer hardware should be simple and not need to be hand-wired for each program. Instead, complex instructions should be used to control the simple hardware, allowing it to be reprogrammed much faster.

The second concept was also extremely important to the development of programming languages. Von Neumann called it “conditional control transfer”. This idea gave rise to the notion of subroutines, or small blocks of code that could be jumped to in any order, instead of a single set of chronologically ordered steps for the computer to take. The second part of the idea stated that computer code should be able to branch based on logical statements such as IF (expression) THEN, and looped such as with a FOR statement. “Conditional control transfer” gave rise to the idea of “libraries, ” which are blocks of code that can be reused over and over.

In 1949, a few years after Von Neumann’s work, the language Short Code appeared. It was the first computer language for electronic devices and it required the programmer to change its statements into 0s and 1s by hand. Still, it was the first step towards the complex languages of today. In 1951, Grace Hopper wrote the first compiler, A-0. A compiler is a program that turns the language’s statements into 0s and 1s for the computer to understand. This led to faster programming, as the programmer no longer had to do the work by hand.