catflap.org Online Dictionary Query

  pattern matching
       
          1. A function is defined to take arguments of a particular
          type, form or value.  When applying the function to its actual
          arguments it is necessary to match the type, form or value of
          the actual arguments against the formal arguments in some
          definition.  For example, the function
       
          	length []     = 0
          	length (x:xs) = 1 + length xs
       
          uses pattern matching in its argument to distinguish a null
          list from a non-null one.
       
          There are well known algorithm for translating pattern
          matching into conditional expressions such as "if" or "case".
          E.g. the above function could be transformed to
       
          	length l = case l of
          		   []   -> 0
          		   x:xs -> 1 : length xs
       
          Pattern matching is usually performed in textual order though
          there are languages which match more specific patterns before
          less specific ones.
       
          2. Descriptive of a type of language or utility such as awk
          or Perl which is suited to searching for strings or patterns
          in input data, usually using some kind of regular
          expression.
       
          (1994-11-28)
       
       

  Pattern matching \Pat"tern match"ing\, n. [See pattern.]
     a technique in automated data analysis, usually performed on
     a computer, by which a group of characteristic properties of
     an unknown object is compared with the comparable groups of
     characteristics of a set of known objects, to discover the
     idenity or proper classification of the unknown object.
  
     Note: There are two major types of pattern matching,
           statistical pattern matching and syntactic pattern
           matching. In statistical pattern matching, the criteria
           used to recognize identity or class membership vary,
           but in general some combination of the differences in
           the groups of characteristics of known and unknown
           objects are considered to be a measure of the
           difference ("distance") between them, and the closest
           known object or objects are viewed as presenting the
           most likely identity or class for the unknown object.
           In syntactic pattern matching, a set of known patterns,
           e.g. as in the possible order of parts of speech in a
           language, is defined, and the unknown pattern is
           compared to find that known pattern or patterns which
           matches the unknown exactly. In general, statistical
           pattern matching is used where properties of objects
           with continuous values are being compared, and
           syntactic pattern matching where a complex arrangement
           of at least two different objects may be built by
           application of a set of rules (a "grammar") for
           combining the objects in a specified order. Examples of
           the latter are natural and formal languages.
           [PJC]

  pattern matching
     n.
     (lb en computer science) the act of checking some sequence of tokens
  for the presence of the constituents of a pattern

  pattern matching
     n.
     (lb en computer science) the act of checking some sequence of tokens
  for the presence of the constituents of a pattern

  pattern matching
     n.
     (lb en computer science) the act of checking some sequence of tokens
  for the presence of the constituents of a pattern

  pattern matching
     n.
     (lb en computer science) the act of checking some sequence of tokens
  for the presence of the constituents of a pattern

  pattern matching /pˈatən mˈatʃɪŋ/ 
  hahmonsovitus
  computer science: act of checking tokens for patterns