delimMatch
Delimited Pattern Matching
Description
Matches the delimited substrings in a character vector.
Usage
delimMatch(x, delim = c("{", "}"), syntax = "Rd")
Arguments
| x |
a character vector to be delimited.
|
| delim |
a character vector. delim must have two delimiters,
and each delimiter must be single characters. They can
be identical.
|
| syntax |
a character string. Indicates the syntax used for the delimiter.
|
Details
Currently, the only syntax supported is Rd. \ is the escape character and %
starts a comment extending to the next newline. It includes no quote characters.
Value
returns an integer vector the same length of x giving the position
of the first opening delimiter, with the attribute "match.length". Also returns the
length of x, giving the number of characters between the opening and matching
closing delimiter (including the delimiters).
If the delimiters are distinct, pairs of delimiters can be nested,
as in \code{{x1};{y2}}. delimMatch matches the text
up to the closing delimiter that is at nesting level 0. In this example,
{{x1};{y2}}.
If there is no set of matched delimiters in a string, -1 is returned for both the starting
position and the match length.
See Also
Examples
txt1 <- "\\code{function(x){ x + 1}} is a function definition"
delimMatch(txt1)
regmatches(txt1, delimMatch(txt1))
txt2 <- "% { (brace in comment)\n\\code{log(2)}"
regmatches(txt2, delimMatch(txt2))
txt3 <- "This is *very* important. Do it *now*!"
regmatches(txt3, delimMatch(txt3, delim=c("*","*")))