str_locate_nth {strex} | R Documentation |
Locate the indices of the n
th instance of a pattern.
Description
The n
th instance of an pattern will cover a series of character
indices. These functions tell you which indices those are. These functions
are vectorised over all arguments.
Usage
str_locate_nth(string, pattern, n)
str_locate_first(string, pattern)
str_locate_last(string, pattern)
Arguments
string |
A character vector. |
pattern |
The pattern to look for. The default interpretation is a regular expression, as described in stringi::about_search_regex. To match a without regular expression (i.e. as a human would), use
coll(). For details see |
n |
A vector of integerish values. Must be either length 1 or
have length equal to the length of |
Details
-
str_locate_first(...)
is juststr_locate_nth(..., n = 1)
. -
str_locate_last(...)
is juststr_locate_nth(..., n = -1)
.
Value
A two-column matrix. The i
th row of this matrix gives the start
and end indices of the n
th instance of pattern
in the i
th
element of string
.
See Also
Other locators:
str_locate_braces()
Examples
str_locate_nth(c("abcdabcxyz", "abcabc"), "abc", 2)
str_locate_nth(
c("This old thing.", "That beautiful thing there."),
"\\w+", c(2, -2)
)
str_locate_nth("abc", "b", c(0, 1, 1, 2))
str_locate_first("abcxyzabc", "abc")
str_locate_last("abcxyzabc", "abc")