delimMatch               package:tools               R Documentation

Delimited Pattern Matching

Description:

     Match delimited substrings in a character vector, with proper
     nesting.

Usage:

     delimMatch(x, delim = c("{", "}"), syntax = "Rd")

Arguments:

       x: a character vector.

   delim: a character vector of length 2 giving the start and end
          delimiters.  Future versions might allow for arbitrary
          regular expressions.

  syntax: currently, always the string '"Rd"' indicating Rd syntax
          (i.e., '%' starts a comment extending till the end of the
          line, and '\' escapes).  Future versions might know about
          other syntaxes, perhaps via 'syntax tables' allowing to
          flexibly specify comment, escape, and quote characters.

Value:

     An integer vector of the same length as 'x' giving the starting
     position (in characters) of the first match, or -1 if there is
     none, with attribute '"match.length"' giving the length (in
     characters) of the matched text (or -1 for no match).

See Also:

     'regexpr' for 'simple' pattern matching.

Examples:

     x <- c("\\value{foo}", "function(bar)")
     delimMatch(x)
     delimMatch(x, c("(", ")"))

