yasp: String Functions for Compact R Code

yasp is a small R package for working with character vectors. It is written in pure base R and has no dependancies. It includes:

paste wrappers with short names and various defaults

mnemonic collapse= sep=
p(), p0() paste, paste0 NULL ""
ps(), pss() paste (sep) space NULL " "
psh() paste sep hyphen NULL "_"
psu() paste sep underscore NULL "-"
psnl() paste sep newline NULL "\n"
pc() paste collapse "" ""
pcs() paste collapse space " " ""
pcc() paste collapse comma ", " ""
pcsc() paste collapse semicolon "; " ""
pcnl() paste collapse newline "\n" ""
pc_and() paste collapse and varies ""
pc_or() paste collapse or varies ""

pc_and and pc_or collapses vectors of length 3 or greater using a serial comma (aka, oxford comma)

pc_and( letters[1:2] )  # "a and b"
pc_and( letters[1:3] )  # "a, b, and c"
pc_or( letters[1:2] )  # "a or b"
pc_or( letters[1:3] )  # "a, b, or c"

unwrap, unparens

Remove pairs of characters from a string

label <- p("name", parens("attribute"))

label             # "name (attribute)"
unparens(label)   # "name attribute"

# by default, removes all matching pairs of left and right
x <- c("a", "(a)", "((a))", "(a) b", "a (b)", "(a) (b)" )
data.frame( x, unparens(x), check.names = FALSE )
#>         x unparens(x)
#> 1       a           a
#> 2     (a)           a
#> 3   ((a))           a
#> 4   (a) b         a b
#> 5   a (b)         a b
#> 6 (a) (b)         a b

specify n_pairs to remove a specific number of pairs

x <- c("(a)", "((a))", "(((a)))", "(a) (b)", "(a) (b) (c)", "(a) (b) (c) (d)")
data.frame( x, "n_pairs=1"   = unparens(x, n_pairs = 1),
               "n_pairs=2"   = unparens(x, n_pairs = 2),
               "n_pairs=3"   = unparens(x, n_pairs = 3),
               "n_pairs=Inf" = unparens(x), # the default 
               check.names = FALSE)
  
#>                 x     n_pairs=1   n_pairs=2 n_pairs=3 n_pairs=Inf
#> 1             (a)             a           a         a           a
#> 2           ((a))           (a)           a         a           a
#> 3         (((a)))         ((a))         (a)         a           a
#> 4         (a) (b)         a (b)         a b       a b         a b
#> 5     (a) (b) (c)     a (b) (c)     a b (c)     a b c       a b c
#> 6 (a) (b) (c) (d) a (b) (c) (d) a b (c) (d) a b c (d)     a b c d

use unwrap() to specify any pair of characters for left and right

x <- "A string with some \\emph{latex tags}."
unwrap(x, "\\emph{", "}")
#> [1] "A string with some latex tags."

by default, only pairs are removed. Set a character to "" to override.

x <- c("a)", "a))", "(a", "((a" )
data.frame(x, unparens(x), 'left=""' = unwrap(x, left = "", right = ")"),
           check.names = FALSE)
  
#>     x unparens(x) left=""
#> 1  a)          a)       a
#> 2 a))         a))       a
#> 3  (a          (a      (a
#> 4 ((a         ((a     ((a

sentence

paste with some additional string cleaning (mostly concerning whitespace) appropriate for prose sentences. It

  • trims leading and trailing whitespace
  • collapses runs of multiple whitespace into a single space
  • appends a period . if there is no terminal punctuation mark (., ?, or !)
  • removes spaces preceding punctuation characters: .?!,;:
  • collapses sequences of punctuation characters (.?!,;:) (possibly separated by spaces), into a single punctuation character. The first punctuation character of the sequence is used, with priority given to terminal punctuation marks .?! if present
  • makes sure a space or end-of-string follows every one of .?!,;:, with an exception for the special case of .,: followed by a digit, indicating the punctuation is a decimal period, number seperator, or time delimiter
  • capitalizes the first letter of each sentence (start-of-string or following a .?!)

Some examples in ?sentence:

compare <- function(x) cat(sprintf(' in: "%s"\nout: "%s"\n', x, sentence(x)))

#>  in: "capitilized and period added"
#> out: "Capitilized and period added."

#>  in: "whitespace:added ,or removed ; like this.and this"
#> out: "Whitespace: added, or removed; like this. And this."

#>  in: "periods and commas in numbers like 1,234.567 are fine !"
#> out: "Periods and commas in numbers like 1,234.567 are fine!"

#>  in: "colons can be punctuation or time : 12:00 !"
#> out: "Colons can be punctuation or time: 12:00!"

#>  in: "only one punctuation at a time!.?,;"
#> out: "Only one punctuation at a time!"

#>  in: "The first mark ,; is kept;,,with priority for terminal marks  ;,."
#> out: "The first mark, is kept; with priority for terminal marks."

# vectorized like paste()
sentence(
 "The", c("first", "second", "third"), "letter is", letters[1:3],
 parens("uppercase:", sngl_quote(LETTERS[1:3])), ".")
#> [1] "The first letter is a (uppercase: 'A')." 
#> [2] "The second letter is b (uppercase: 'B')."
#> [3] "The third letter is c (uppercase: 'C')."

Installation

You can install ‘yasp’ from CRAN with:

install.packages("yasp")

Or install from github with:

# install.packages("devtools")
devtools::install_github("t-kalinowski/yasp")