LISP is a programming language that has an overall style that is organized around expressions and functions. Every Lisp procedure is a function, and when called, it returns a data object as its value. It is also commonly referred to as “functions” even though they may have side effects.
Lisp is the second-oldest high-level programming language in the world which is invented by John McCarthy in the year 1958 at the Massachusetts Institute of Technology.
Features of LISP Programming Language
- LISP is a machine-independent language and is based on an iterative design methodology.
- It is an extensible and expression-based language.
- It can dynamically create and update programs and applications.
- It provides debugging and supports object-oriented programming.
- It supports all kinds of:
- Data types: objects, structures, lists, vectors, adjustable arrays, sets, trees,hash-tables, and symbols and different decision-making statements like if, when, case, and cond.
- Iterating statements: Like do, loop, loopfor, dotimes, and dolist.
- It will support input and output functions and user-defined functions
Let’s say for writing “GeeksforGeeks” we can use the below syntax:
Syntax:
(write-line string)
Example:
(write-line "GeeksforGeeks")
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Output:
GeeksforGeeks
Explanation: The write-line is a method that writes the specified line on the output stream. We have passed “GeeksforGeeks” as a string.
Now let’s look into the Naming Conventions in LISP.
Naming Conventions:
The naming Conventions mean the way we are declaring variables in a program. It includes the variable names and syntax formats
Lets us discuss the conventions:
A variable can contain any number of alphanumeric characters other than whitespace, open, and closing parentheses.
Example:
Acceptable: hello,akshit, etc
Not Acceptable: hell()0,sat{ akshit{,,,,,,,,etcA variable can not contain double and single quotes, backslash, comma, colon, semicolon, and vertical bar.
Example:
Acceptable: hello,akshit, etc
Not Acceptable: hell””)0,sat//*& aka//>vab{,,,,,,,,etcA variable can not start with a digit but it can contain any number of digits
Example:
Acceptable: hello88Geeks, a45akshit, ,,,,,etc Not Acceptable: 40geeks,4akshit,….etc
Now let’s take a look at a couple of examples to better understand the Naming convention in LISP.
Example 1: Naming Conventions in LISP.
;acceptable naming conventions (write-line "akshit")
(terpri) (write-line "akshit99")
(terpri) (write-line "hello geeks")
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Output:
akshit akshit99 hello geeks
Example 2: Naming Conventions in LISP.
;acceptable naming conventions (write-line "hello_Geek")
(terpri) (write-line "hello123")
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Output:
hello_Geek hello123