Functions for creating and checking lyrics objects.
lyrical(x)
as_lyrics(x, format = NULL)
is_lyrics(x)
lyrics_template(x, format = NULL)depends on the function
The lyrics class is a simple class for arranging lyrics text by timestep.
Its structure and behavior aligns with that of the classes noteworthy,
noteinfo and music.
lyrical() is a trivial function that returns a scalar logical result
essentially for any object that inherits from character, though this check
may become more specific in the future.
as_lyrics() can be used to coerce to the lyrics class. Coercion will fail
if the string is not lyrical. The lyrics class has its own print() and
summary() methods.
When format = NULL, the timestep delimiter format is inferred from the
lyrical string input.
# space-delimited lyrics; use periods for timesteps with no lyric
x <- "These are the ly- rics . . . to this song"
is_lyrics(x)
#> [1] FALSE
lyrical(x)
#> [1] TRUE
as_lyrics(x)
#> <Lyrics string>
#> Format: space-delimited time
#> Values: These are the ly- rics . . . to this song
# character vector; empty, period or NA for no lyric
x <- c("These", "are", "the", "ly-", "rics",
"", ".", NA, "to", "this", "song") #
as_lyrics(x)
#> <Lyrics string>
#> Format: vectorized time
#> Values: These are the ly- rics . . . to this song
# generate empty lyrics object from noteworthy, noteinfo or music object
notes <- as_noteworthy("c d e d c r*3 e g c'")
x <- lyrics_template(notes)
x
#> <Lyrics string>
#> Format: space-delimited time
#> Values: . . . . . . . . . . .
x[1:5] <- strsplit("These are the ly- rics", " ")[[1]]
x[9:11] <- c("to", "this", "song")
x
#> <Lyrics string>
#> Format: space-delimited time
#> Values: These are the ly- rics . . . to this song
summary(x)
#> <Lyrics string>
#> Timesteps: 11 (8 lyrics, 3 pauses)
#> Format: space-delimited time
#> Values: These are the ly- rics . . . to this song
attributes(x)
#> $steps
#> [1] 11
#>
#> $n_lyric
#> [1] 8
#>
#> $n_pause
#> [1] 3
#>
#> $format
#> [1] "space-delimited time"
#>
#> $class
#> [1] "lyrics" "character"
#>