Definitions for s-expression
s-expres·sion

WiktionaryRate this definition:5.0 / 1 vote

1. S-expressionnoun

   A symbolic expression.

WikipediaRate this definition:0.0 / 0 votes

1. S-expression

   In computer programming, an S-expression (or symbolic expression, abbreviated as sexpr or sexp) is an expression in a like-named notation for nested list (tree-structured) data. S-expressions were invented for and popularized by the programming language Lisp, which uses them for source code as well as data. In the usual parenthesized syntax of Lisp, an S-expression is classically defined as an atom of the form x, or an expression of the form (x . y) where x and y are S-expressions.This definition reflects LISP's representation of a list as a series of "cells", each one an ordered pair. In plain lists, y points to the next cell (if any), thus forming a list. The recursive clause of the definition means that both this representation and the S-expression notation can represent any binary tree. However, the representation can in principle allow circular references, in which cases the structure is not a tree at all, but a cyclic graph, and cannot be represented in classical S-expression notation unless a convention for cross-reference is provided (analogous to SQL foreign keys, XML IDREFs, etc.). Modern Lisp dialects such as Common Lisp and Scheme provide such syntax via datum labels, with which objects can be marked, which can then recur elsewhere, indicating shared structure rather than object duplication, enabling the reader or printer to detect and thus trigger evaluation or display of cycles without infinitely recursing #n=(x y . #n#)The definition of an atom varies per context; in the original definition by John McCarthy, it was assumed that there existed "an infinite set of distinguishable atomic symbols" represented as "strings of capital Latin letters and digits with single embedded blanks" (a subset of character string and numeric literals). Most modern sexpr notations allow more general quoted strings (for example including punctuation or full Unicode), and use an abbreviated notation to represent lists with more than 2 members, so that (x y z)stands for (x . (y . (z . NIL)))NIL is the special end-of-list object (alternatively written (), which is the only representation in Scheme). In the Lisp family of programming languages, S-expressions are used to represent both source code and data. Other uses of S-expressions are in Lisp-derived languages such as DSSSL, and as mark-up in communication protocols like IMAP and John McCarthy's CBCL. It's also used as text representation of WebAssembly. The details of the syntax and supported data types vary in the different languages, but the most common feature among these languages is the use of S-expressions and prefix notation.

WikidataRate this definition:0.0 / 0 votes

1. S-expression

   In computing, s-expressions, sexprs or sexps are a notation for nested list data, invented for and popularized by the programming language Lisp, which uses them for source code as well as data. In the usual parenthesized syntax of Lisp, an s-expression is classically defined inductively as ⁕an atom, or ⁕an expression of the form where x and y are s-expressions. The second, recursive part of the definition represents an ordered pair so that s-exprs are effectively binary trees. The definition of an atom varies per context; in the original definition by John McCarthy, it was assumed that there existed "an infinite set of distinguishable atomic symbols" represented as "strings of capital Latin letters and digits with single embedded blanks". Most modern sexpr notations in addition use an abbreviated notation to represent lists in s-expressions, so that stands for where NIL is the special end-of-list symbol. In the Lisp family of programming languages, s-expressions are used to represent both source code and data. Other uses of S-expressions are in Lisp-derived languages such as DSSSL, and as mark-up in communications protocols like IMAP and John McCarthy's CBCL. The details of the syntax and supported data types vary in the different languages, but the most common feature among these languages is the use of S-expressions and prefix notation.

Anagrams for s-expression »

1. expressions

How to pronounce s-expression?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say s-expression in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of s-expression in Chaldean Numerology is: 2

2. Pythagorean Numerology

   The numerical value of s-expression in Pythagorean Numerology is: 1

Examples of s-expression in a Sentence

1. Debbie Allen:

   We are all trying to heal, whether we have this virus right now or not. We are connected -- every last one of us, everyone knows somebody that has it. Everyone is in a community that is threatened by it. There's not place on this planet that is free of it. So this dance is an expression of joy and freedom and self-will. You are willing yourself to be powerful and you are willing yourself to breathe and be free and to face any challenge.

2. Tim Soutphommasane:

   In the past, this had its most potent expression in the form of the Fortress Australia immigration policy.

3. Rachel Johnson:

   There was just bad fashion being passed along from season to season and now that there's been this huge fashion evolution, younger players come in and they really understand that they can utilize fashion as a vehicle to express themselves, to express their brand, i think that that same kind of freedom, and that same kind of courage, that same kind of level of expression is going to be handed down to the young players as they come up, through the political lens.

4. The Dalai Lama:

   Dear brothers and sisters, I really appreciate so many people's expression of warmth.

5. Ilya Shapiro:

   All I'll say is, I'm looking forward to a professional and efficient process, although there's not much to investigate, and I look forward to being vindicated based on the university's policies on free expression.

References

1. ^ Wiktionary
   https://en.wiktionary.org/wiki/S-Expression
2. ^ Wikipedia
   https://en.wikipedia.org/wiki/S-Expression
3. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=s-expression