R: Extract Data Between Text Boundaries

stri_extract_all_boundaries {stringi} | R Documentation

## Extract Data Between Text Boundaries

### Description

These functions extract data between text boundaries.

### Usage

    stri_extract_all_boundaries(
      str,
      simplify = FALSE,
      omit_no_match = FALSE,
      ...,
      opts_brkiter = NULL
    )

    stri_extract_last_boundaries(str, ..., opts_brkiter = NULL)

    stri_extract_first_boundaries(str, ..., opts_brkiter = NULL)

    stri_extract_all_words(
      str,
      simplify = FALSE,
      omit_no_match = FALSE,
      locale = NULL
    )

    stri_extract_first_words(str, locale = NULL)

    stri_extract_last_words(str, locale = NULL)

### Arguments

`str` | character vector or an object coercible to
`simplify` | single logical value; if `TRUE` or `NA`, then a character matrix is returned; otherwise (the default), a list of character vectors is given, see Value
`omit_no_match` | single logical value; if `FALSE`, then a missing value will indicate that there are no words
`...` | additional settings for `opts_brkiter`
`opts_brkiter` | a named list with ICU BreakIterator's settings, see `stri_opts_brkiter`; `NULL` for the default break iterator, i.e., `line_break`
`locale` | `NULL` or `""` for text boundary analysis following the conventions of the default locale, or a single string with locale identifier, see stringi-locale

### Details

Vectorized over `str`.

For more information on text boundary analysis performed by ICU's `BreakIterator`, see stringi-search-boundaries.

In case of `stri_extract_*_words`, just like in `stri_count_words`, ICU's word `BreakIterator` iterator is used to locate the word boundaries, and all non-word characters (`UBRK_WORD_NONE` rule status) are ignored.

### Value

For `stri_extract_all_*`, if `simplify=FALSE` (the default), then a list of character vectors is returned. Each string consists of a separate word. In case of `omit_no_match=FALSE` and if there are no words or if a string is missing, a single `NA` is provided on output.

Otherwise, `stri_list2matrix` with `byrow=TRUE` argument is called on the resulting object. In such a case, a character matrix with `length(str)` rows is returned. Note that `stri_list2matrix`'s `fill` argument is set to an empty string and `NA`, for `simplify` `TRUE` and `NA`, respectively.

For `stri_extract_first_*` and `stri_extract_last_*`, a character vector is returned. A `NA` element indicates a no-match.

### See Also

Other search_extract: `stri_extract_all()`, `stri_match_all()`, `stringi-search`

Other locale_sensitive: `%s<%()`, `stri_compare()`, `stri_count_boundaries()`, `stri_duplicated()`, `stri_enc_detect2()`, `stri_locate_all_boundaries()`, `stri_opts_collator()`, `stri_order()`, `stri_sort()`, `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_locate_all_boundaries()`, `stri_opts_brkiter()`, `stri_split_boundaries()`, `stri_split_lines()`, `stri_trans_tolower()`, `stri_wrap()`, `stringi-search-boundaries`, `stringi-search`

### Examples

    stri_extract_all_words("stringi: THE string processing package 123.48...")

[Package stringi version 1.4.6 Index]