R: Delimited Pattern Matching

delimMatch {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 syntax, 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("(", ")"))

[Package tools version 2.8.1 Index]