R: Declare a pattern to be a sequence of separate patterns

phrase {quanteda} | R Documentation

## Declare a pattern to be a sequence of separate patterns

### Description

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"))
    phrase(c("natural_language_processing", "text_analysis"), separator = "_")

    # from a dictionary
    phrase(dictionary(list(catone = c("a b"), cattwo = "c d e", catthree = "f")))

    # from a list
    as.phrase(list(c("natural", "language", "processing")))

    # from tokens
    as.phrase(tokens("natural language processing"))

[Package quanteda version 3.1.0 Index]