1) Explain what is LISP? Give an example of some of the popular applications built in LISP? LISP stands for List Processing, it is also a high-level programming language based on formal functional calculus. This language is used for easy manipulation of data strings. It is used for Artificial Intelligence. Some of the popular applications built in LISP are • Yahoo Store • AutoCad • G2 • Emacs • Igor Engraver 2) Why LISP is used for Artificial Intelligence? LISP is used for Artificial Intelligence for following reasons • It supports the symbolic programming, and old AI was based on symbols • LISP is powerful. The code or data distinction is weaker, so it feels more extensible than other programming languages which make it feels like a domain specific language • It is an excellent prototyping tool and good at tackling problems 3) Demonstrate with an example how you can code in LISP? Almost everything in LISP is a function, even the mathematical operators. For example, (+ (* 5 3) 1) The output will be 16, functions in LISP open and close with parenthesis.
11 parse-integer string & key:start:end:radix:junk-allowed It examines the substring of string delimited by:start and:end (default to the beginning and end of the string). It skips over whitespace characters and then attempts to parse an integer. 12 read-byte binary-input-stream & optional eof-error-p eof-value It reads one byte from the binary-input-stream and returns it in the form of an integer. Reading Input from Keyboard The read function is used for taking input from the keyboard. It may not take any argument. For example, consider the code snippet − (write ( + 15. 0 (read))) Assume the user enters 10. 2 from the STDIN Input, it returns, 25. 2 The read function reads characters from an input stream and interprets them by parsing as representations of Lisp objects. Example Create a new source code file named and type the following code in it −; the function AreaOfCircle; calculates area of a circle; when the radius is input from keyboard (defun AreaOfCircle() (terpri) (princ "Enter Radius: ") (setq radius (read)) (setq area (* 3.
write-byte integer binary-output-stream It writes one byte, the value of the integer. Create a new source code file named and type the following code in it. ; this program inputs a numbers and doubles it (defun DoubleNumber() (princ "Enter Number: ") (setq n1 (read)) (setq doubled (* 2. 0 n1)) (princ "The Number: ") (write n1) (princ "The Number Doubled: ") (write doubled)) (DoubleNumber) Enter Number: 3456. 78 (STDIN Input) The Number: 3456. 78 The Number Doubled: 6913. 56 Formatted Output The function format is used for producing nicely formatted text. It has the following syntax − format destination control-string &rest arguments where, destination is standard output control-string holds the characters to be output and the printing directive. A format directive consists of a tilde (~), optional prefix parameters separated by commas, optional colon (:) and at-sign (@) modifiers, and a single character indicating what kind of directive this is. The prefix parameters are generally integers, notated as optionally signed decimal numbers.
Other values default to the corresponding global variables set for printing. prin1 object & optional output-stream print object & optional output-stream pprint object & optional output-stream princ object & optional output-stream All these functions outputs the printed representation of object to output-stream. However, the following differences are there − prin1 returns the object as its value. print prints the object with a preceding newline and followed by a space. It returns object. pprint is just like print except that the trailing space is omitted. princ is just like prin1 except that the output has no escape character write-to-string object & key:escape:radix:base:circle:pretty:level:length:case:gensym:array write-to-string object & key:escape:radix:base:circle:pretty:level:length:case:gensym:array:readably:right-margin:miser-width:lines:pprint-dispatch prin1-to-string object princ-to-string object The object is effectively printed and the output characters are made into a string, which is returned.
we can quit your lisp session by getting to the command line (possibly through pressing Control-C), then typing (quit) and pressing return. [1]> (quit) Bye. After typing (quit) on command line common clisp replies Bye which indicates that out session is terminated. The Common LISP environment follows the algorithm below when interacting with users: loop read in an expression from the console; evaluate the expression; print the result of evaluation to the console; end loop. Common LISP reads in an expression, evaluates it, and then prints out the result. For example, if we want to compute the value of (2 * cos(0) * (4 + 6)), we type in: [1]> (* 2 (cos 0) (+ 4 6)) Common LISP replies: 20. 0 before prompting you to enter the next expression. Several things are worth noting: LISP expressions are composed of forms. The most common LISP form is function application. LISP represents a function call f(x) as (f x). For example, cos(0) is written as (cos 0). LISP expressions are case-insensitive.
I guess for CL I am just not sure how to make the jump from tinkering around in the REPL or with very limited code inside a small number of files, to encapsulated bits of functionality that I can start using in other projects. Programming in the "medium" if you will, if not the large. I am guessing that just saving my image and storing that in the repo isn't a long term solution either, as that is definitely not how I would do larger Smalltalk development. Any help you have here, even if it is just RTFM (although hopefully more than that), would be greatly appreciated.
Do I separate that code out into packages, with each package being a file? Do I need to start reading up on ASDF? How do I express a dependency between my current problem based code and the utility library I extracted out from a previous solution? Should all of this work correctly in the face of quicklisp as well? In Smalltalk I get the progression, I create a new Category to store my Classes, create a new Class to store my methods, and then categorize my methods. I can file this code out if I want to save it to github or something similar, and then file it in in another image on another computer. For scheme I would use some define-library calls and place each library in a new file, and include the files my library needs and import the needed libraries. All of this is just files so it can naturally be stored in a repo. In Java I create classes, inside of packages, that get bundled into jars, which I can, again, have dependencies on, and grab the packages I need. This is how I would scale up from a 50 line project, to quite a large project in the java world.