Stropping

Stropping

When applied to computer languages, stropping refers to the method used to mark letter sequences as having a special property (most often being a keyword or certain type of variable/storage location). For instance, some implementations of Algol 68 [http://www.fh-jena.de/~kleine/history/languages/Algol68-RR-HardwareRepresentation.pdf] [van Wijngarten et al (1976) Section 9.3] treat letter sequences prefixed by a single quote, ', as being keywords (e.g., 'BEGIN) [Lindsey and van der Meulen (1977) pp.348-349] whereas Algol 60 commonly used only the convention of quotes around the word (e.g. 'BEGIN' or ‘BEGIN’). In fact it was often the case that several stropping conventions might be in use within the one language, and sometimes even within the one language processor, such as ALGOL 68RS. The Atlas Autocode compiler had the choice of three: keywords could be underlined using backspace and overstrike on a Flexowriter keyboard, they could be introduced by a %percent %symbol, or they could be typed in UPPER CASE with no delimiting character (in which case all variables had to be in lower case).

The use of stropping allows the same letter sequence to be used both as a keyword and as an identifier. Most modern programming languages do not use stropping. Exceptions include Ruby and Perl, both of which use sigils to identify characteristics of variables/constants (Perl uses sigils to designate the type of variable, Ruby uses it to distinguish variables from constants and scope). As well as increasing the set of identifiers available, stropping allowed for a much more efficient lexical pre-pass (commonly called 'line reconstruction') before parsing, virtually eliminating the need for a complex lexer such as Lex.

ee also

* Escape character

References

References

*
*
*


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Stropping — Strop Strop, v. t. [imp. & p. p. {Stropped}; p. pr. & vb. n. {Stropping}.] To draw over, or rub upon, a strop with a view to sharpen; as, to strop a razor. [1913 Webster] …   The Collaborative International Dictionary of English

  • stropping — strÉ‘p /strÉ’p n. flexible leather strap for sharpening razors v. sharpen on or with a strop …   English contemporary dictionary

  • stropping — present part of strop …   Useful english dictionary

  • ALGOL 68 — Infobox programming language name = ALGOL 68 paradigm = multi paradigm: concurrent bull; imperative year = 1968, last revised 1973 designer = A. van Wijngaarden, B.J. Mailloux, J.E.L. Peck and C.H.A. Koster, et al. developer = latest release… …   Wikipedia

  • Straight razor — A straight razor with square point and a double transverse stabiliser Main article: Razor A straight razor is a razor with a blade that can fold into its handle.[1] …   Wikipedia

  • ALGOL — This article is about the programming language family. For other uses, see Algol (disambiguation). ALGOL Paradigm(s) procedural, imperative, structured Appeared in 1958 Designed by Bauer, Bottenbruch, Rutishauser, Samelson, Backus, Katz, Perlis …   Wikipedia

  • ALGOL 68G — or Algol 68 Genie is an ALGOL 68 interpreter. ALGOL 68G is a nearly full implementation of ALGOL 68 as defined by the Revised Report and also implements partial parametrisation, which is an extension of ALGOL 68.After successful parsing of an… …   Wikipedia

  • Strop — Strop, v. t. [imp. & p. p. {Stropped}; p. pr. & vb. n. {Stropping}.] To draw over, or rub upon, a strop with a view to sharpen; as, to strop a razor. [1913 Webster] …   The Collaborative International Dictionary of English

  • Stropped — Strop Strop, v. t. [imp. & p. p. {Stropped}; p. pr. & vb. n. {Stropping}.] To draw over, or rub upon, a strop with a view to sharpen; as, to strop a razor. [1913 Webster] …   The Collaborative International Dictionary of English

  • strop — I. noun Etymology: Middle English more at strap Date: before 12th century strap: a. a short rope with its ends spliced to form a circle b. a usually leather band for sharpening a razor II. transitive verb (stropped; stropping) Date: 1837 to… …   New Collegiate Dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”