SNOBOL

The string-oriented symbolic language (SNOBOL) is a programming language family created by computer scientists at Bell Laboratories in the 1960s. SNOBOL4 was the final and most widely used version. Several successor languages have been developed, and some of the language’s distinctive features have remained influential. SNOBOL was designed to manipulate symbolic string data, as its name suggests. In only a few lines of code, programmers may quickly search, edit, and use string variables. Pattern-matching problems are well-suited to SNOBOL and derivative languages.

Principal Terms:

In computer programming, a function is a self-contained chunk of code that performs a specific purpose.

Patterns are repetitive sequences or designs of code in computer programming.

Stack: data structure in computer science that only enables access to the most recently inserted object.

A statement is a command that tells a computer what action to take.

A string is a data type in computer programming that consists of characters ordered in a certain order.

In computer programming, a variable is a symbolic name for data stored in a specific location in a computer’s memory and whose value may be altered.

SNOBOL Data Types:

SNOBOL was created with the purpose of manipulating strings and matching patterns. The creators included just the functionality they required into the original SNOBOL language because it was originally intended for usage primarily at Bell Labs. There was just one data type, no functions, and little error management. The team added further features when other programmers expressed interest in a string-oriented language. Although SNOBOL2 was not widely distributed, it did add the ability to employ functions. SNOBOL3 gained popularity after adding the ability to write user-defined functions.

SNOBOL3 was exclusively created for the IBM 7090 machine at the time, which limited its application. Several programmers tried to create identical versions for other machines, but these were frequently flawed. SNOBOL4 solved the compatibility issue by letting it operate in a virtual machine that could be utilised on a variety of systems. Arrays, tables, stacks, and other popular features and data types might also be used by SNOBOL4.

SNOBOL – Language features:

• Statements- In SNOBOL, there is just one statement format, however each component is optional.

• Dynamic variables- Variables do not need to be declared ahead of time, and their values can readily change types.

• Arrays, tables and data types- ARRAY may be used to define and initialise arrays.

• Control flow- In SNOBOL, the sole control flow accessible is goto. Each sentence is evaluated for success or failure, and a move to the next statement can be made conditionally or dependent on the result.

• Pattern matching- Many additional pattern matching constructions are available in SNOBOL; a few are shown below, along with a string that might be a good match

• Replacement and assignment- Pattern replacement can be used to make a basic replacement.

Modern Usage:

• SNOBOL was designed to work with symbolic string data. In only a few lines of code, programmers may quickly search, edit, and use string variables. Pattern-matching problems are well-suited to SNOBOL and derivative languages.

• In 1967, the last official version of SNOBOL, SNOBOL4, was published. It was popular until the 1980s, when object-oriented languages like Perl became more popular for text manipulation using regular expressions. Regular expressions, in contrast to pattern matching, discover patterns in text using a suite of string-searching methods. With the addition of more functionality, object-oriented languages became the preferred approach to handle strings in all but a few circumstances.

• SNOBOL was a forerunner in the field of string manipulation, and it served as a model for subsequent programming languages. 

• Attempts to resurrect SNOBOL have been made over the years. In the late 1970s, Ralph Griswold, the creator of SNOBOL, produced Icon, a language that was comparable to SNOBOL. It was never as popular as SNOBOL because it was too specialized. Specialists in compilers, natural language recognition, and grammar analysis did, however, pay attention to it. Griswold also created SL5, a language that focuses on string processing. SNOBOL and Icon were the inspirations for Unicon, an object-oriented language developed decades later.

File extension:

The majority of SNO files are PDP-10 files. The PDP-10, or Programmed Data Processor model 10, was a mainframe computer produced by Digital Equipment Corporation (DEC) in the late 1960s. The VAX supermini computers finally surpassed the PDP-10. The termination of the PDP-10 product line was announced in 1983. REL files are generated by compilers.

The .sno file extension is connected with the Snobol4 (StriNg Oriented and symBOlic Language) language, which is used for text processing, pattern matching, and other tasks.

Snobol4 source code is stored in the .sno file.

Conclusion:

The syntax and labels of SNOBOL were created by the Bell Labs team to imitate speech, making it intelligible even to novice programmers. Logic, operators, arrays, and typical loops are all used in the language. Because SNOBOL is dynamically typed, the programmer does not need to define the type of variable that will be used. All variables are global, and goto commands, which are ubiquitous in older languages and machine languages, are often used in SNOBOL applications. Object-oriented languages, on the other hand, manage bigger blocks of code called “objects,” whereas this linear approach to programming is in stark contrast.