Declares that a character expression consists of multiple patterns, separated
by an element such as whitespace. This is typically used as a wrapper around
pattern()
to make it explicit that the pattern elements are to be used for
matches to multi-word sequences, rather than individual, unordered matches to
single words.
phrase(x, separator = " ")
as.phrase(x)
is.phrase(x)
character, dictionary, list, collocations, or tokens object; the
compound patterns to be treated as a sequence separated by separator
.
For list, collocations, or tokens objects, use as.phrase()
.
character; the character in between the patterns. This
defaults to " ". For phrase()
only.
phrase()
and as.phrase()
return a specially classed list whose
elements have been split into separate character
(pattern) elements.
is.phrase
returns TRUE
if the object was created by
phrase()
; FALSE
otherwise.
as.phrase()
# make phrases from characters
phrase(c("natural language processing"))
#> [[1]]
#> [1] "natural" "language" "processing"
#>
phrase(c("natural_language_processing", "text_analysis"), separator = "_")
#> [[1]]
#> [1] "natural" "language" "processing"
#>
#> [[2]]
#> [1] "text" "analysis"
#>
# from a dictionary
phrase(dictionary(list(catone = c("a b"), cattwo = "c d e", catthree = "f")))
#> [[1]]
#> [1] "a" "b"
#>
#> [[2]]
#> [1] "c" "d" "e"
#>
#> [[3]]
#> [1] "f"
#>
# from a list
as.phrase(list(c("natural", "language", "processing")))
#> [[1]]
#> [1] "natural" "language" "processing"
#>
# from tokens
as.phrase(tokens("natural language processing"))
#> [[1]]
#> [1] "natural" "language" "processing"
#>