Count pattern matches in documents

ac_count() returns the number of pattern matches in each document.

Usage

ac_count(ac, doc, overlapping = FALSE, na = c("keep", "zero", "error"))

Arguments

ac

An <ac_automaton> object created by ac_build().

doc

A character vector of documents to search.

overlapping

Default is FALSE. If TRUE, count overlapping matches. This is only supported when ac was built with match_kind = "standard".

na

How to handle NA documents. "keep" returns NA_integer_ (default); "zero" treats missing documents as zero matches; "error" fails.

Value

An integer vector with the same length as doc.

See also

ac_count_file(), ac_detect(), ac_locate(), ac_extract().

Examples

if (requireNamespace("dplyr", quietly = TRUE)) {
  ac <- ac_build(c("hello", "world"))
  docs <- data.frame(doc = c("hello world", "nothing", "world"))
  dplyr::mutate(docs, n_matches = ac_count(ac, doc))
}
#>           doc n_matches
#> 1 hello world         2
#> 2     nothing         0
#> 3       world         1