Editing Pattern matching (section)

====SNOBOL====
{{Main|SNOBOL}}
SNOBOL (''StriNg Oriented and symBOlic Language'') is a computer programming language developed between 1962 and 1967 at [[AT&T Corporation|AT&T]] [[Bell Laboratories]] by [[David J. Farber]], [[Ralph E. Griswold]] and Ivan P. Polonsky.

SNOBOL4 stands apart from most programming languages by having patterns as a [[first-class object|first-class data type]] (''i.e.'' a data type whose values can be manipulated in all ways permitted to any other data type in the programming language) and by providing operators for pattern [[concatenation]] and [[alternation (formal language theory)|alternation]]. Strings generated during execution can be treated as programs and executed.

SNOBOL was quite widely taught in larger US universities in the late 1960s and early 1970s and was widely used in the 1970s and 1980s as a text manipulation language in the [[humanities]].

Since SNOBOL's creation, newer languages such as [[AWK]] and [[Perl]] have made string manipulation by means of [[regular expression]]s fashionable. SNOBOL4 patterns, however, subsume [[Backus–Naur form]] (BNF) grammars, which are equivalent to [[context-free grammar]]s and more powerful than [[regular expression]]s.<ref>Gimpel, J. F. 1973. A theory of discrete patterns and their implementation in SNOBOL4. Commun. ACM 16, 2 (Feb. 1973), 91–100. DOI=http://doi.acm.org/10.1145/361952.361960.</ref>