These functions locate specific text boundaries
(like character, word, line, or sentence boundaries).
stri_locate_all_*
locate all the matches.
On the other hand, stri_locate_first_*
and stri_locate_last_*
give the first or the last matches, respectively.
stri_locate_all_boundaries(str, omit_no_match = FALSE, ...,
opts_brkiter = NULL)stri_locate_last_boundaries(str, ..., opts_brkiter = NULL)
stri_locate_first_boundaries(str, ..., opts_brkiter = NULL)
stri_locate_all_words(str, omit_no_match = FALSE, locale = NULL)
stri_locate_last_words(str, locale = NULL)
stri_locate_first_words(str, locale = NULL)
character vector or an object coercible to
single logical value; if FALSE
,
then 2 missing values will indicate that there are no text boundaries
additional settings for opts_brkiter
a named list with ICU BreakIterator's settings
as generated with stri_opts_brkiter
;
NULL
for default break iterator, i.e. line_break
NULL
or ""
for text boundary analysis following
the conventions of the default locale, or a single string with
locale identifier, see stringi-locale
For stri_locate_all_*
, a list of length(str)
integer matrices
is returned. The first column gives the start positions
of substrings between located boundaries, and the second column gives
the end positions. The indices are code point-based, thus
they may be passed e.g. to the stri_sub
function.
Moreover, you may get two NA
s in one row
for no match (if omit_no_match
is FALSE
)
or NA
arguments.
stri_locate_first_*
and stri_locate_last_*
,
on the other hand, return an integer matrix with
two columns, giving the start and end positions of the first
or the last matches, respectively, and two NA
s if and
only if they are not found.
Vectorized over str
.
For more information on the text boundary analysis
performed by ICU's BreakIterator
, see
stringi-search-boundaries.
In case of stri_locate_*_words
,
just like in stri_extract_all_words
and stri_count_words
,
ICU's word BreakIterator
iterator is used
to locate word boundaries, and all non-word characters
(UBRK_WORD_NONE
rule status) are ignored.
This is function is equivalent to a call to
stri_locate_*_boundaries(str, type="word", skip_word_none=TRUE, locale=locale)
Other search_locate: stri_locate_all
,
stringi-search
Other indexing: stri_locate_all
,
stri_sub
Other locale_sensitive: %s<%
,
stri_compare
,
stri_count_boundaries
,
stri_duplicated
,
stri_enc_detect2
,
stri_extract_all_boundaries
,
stri_opts_collator
,
stri_order
,
stri_split_boundaries
,
stri_trans_tolower
,
stri_unique
, stri_wrap
,
stringi-locale
,
stringi-search-boundaries
,
stringi-search-coll
Other text_boundaries: stri_count_boundaries
,
stri_extract_all_boundaries
,
stri_opts_brkiter
,
stri_split_boundaries
,
stri_split_lines
,
stri_trans_tolower
,
stri_wrap
,
stringi-search-boundaries
,
stringi-search
# NOT RUN {
test <- "The\u00a0above-mentioned features are very useful. Warm thanks to their developers."
stri_locate_all_boundaries(test, type="line")
stri_locate_all_boundaries(test, type="word")
stri_locate_all_boundaries(test, type="sentence")
stri_locate_all_boundaries(test, type="character")
stri_locate_all_words(test)
# }
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