Declare a pattern to be a sequence of separate patterns

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.

Usage

phrase(x, separator = " ")

as.phrase(x)

is.phrase(x)

Arguments

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().

separator

character; the character in between the patterns. This defaults to " ". For phrase() only.

Value

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.

See also

as.phrase()

Examples

# 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"
#>