Doc/libregsub.tex

   1 \section{Standard Module \sectcode{regsub}}
   2
   3 \stmodindex{regsub}
   4 This module defines a number of functions useful for working with
   5 regular expressions (see built-in module \code{regex}).
   6
   7 \renewcommand{\indexsubitem}{(in module regsub)}
   8 \begin{funcdesc}{sub}{pat\, repl\, str}
   9 Replace the first occurrence of pattern \var{pat} in string
  10 \var{str} by replacement \var{repl}.  If the pattern isn't found,
  11 the string is returned unchanged.  The pattern may be a string or an
  12 already compiled pattern.  The replacement may contain references
  13 \samp{\e \var{digit}} to subpatterns and escaped backslashes.
  14 \end{funcdesc}
  15
  16 \begin{funcdesc}{gsub}{pat\, repl\, str}
  17 Replace all (non-overlapping) occurrences of pattern \var{pat} in
  18 string \var{str} by replacement \var{repl}.  The same rules as for
  19 \code{sub()} apply.  Empty matches for the pattern are replaced only
  20 when not adjacent to a previous match, so e.g.
  21 \code{gsub('', '-', 'abc')} returns \code{'-a-b-c-'}.
  22 \end{funcdesc}
  23
  24 \begin{funcdesc}{split}{str\, pat}
  25 Split the string \var{str} in fields separated by delimiters matching
  26 the pattern \var{pat}, and return a list containing the fields.  Only
  27 non-empty matches for the pattern are considered, so e.g.
  28 \code{split('a:b', ':*')} returns \code{['a', 'b']} and
  29 \code{split('abc', '')} returns \code{['abc']}.
  30 \end{funcdesc}