Concatenating vectors into human-readable strings

Concatenating vectors into human-readable strings such as "1, 2, 3, ..., 10".

# S3 method for default
hpaste(..., sep="", collapse=", ", lastCollapse=NULL,
  maxHead=if (missing(lastCollapse)) 3 else Inf,
  maxTail=if (is.finite(maxHead)) 1 else Inf, abbreviate="...", empty=character(0L))

Arguments

...

Arguments to be pasted.

sep

A character string used to concatenate the arguments in ..., if more than one.

collapse, lastCollapse

The character strings to collapse the elements together, where lastCollapse is specifying the collapse string used between the last two elements. If lastCollapse is NULL (default), it is corresponds to using the default collapse.

maxHead, maxTail, abbreviate

Non-negative integers (also Inf) specifying the maximum number of elements of the beginning and then end of the vector to be outputted. If n = length(x) is greater than maxHead+maxTail+1, then x is truncated to consist of x[1:maxHead], abbreviate, and x[(n-maxTail+1):n].

empty

A character string, or character(0) (default), to be returned in case the result is of length zero.

Value

Returns a character string.

Details

hpaste(..., sep=" ", maxHead=Inf) corresponds to paste(..., sep=" ", collapse=", ").

Author

Henrik Bengtsson

See also

Internally paste() is used.

Examples

# Some vectors
x <- 1:6
y <- 10:1
z <- LETTERS[x]

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Abbreviation of output vector
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
printf("x = %s.\n", hpaste(x))
#> x = 1, 2, 3, ..., 6.
## x = 1, 2, 3, ..., 6.

printf("x = %s.\n", hpaste(x, maxHead=2))
#> x = 1, 2, ..., 6.
## x = 1, 2, ..., 6.

printf("x = %s.\n", hpaste(x, maxHead=3)) # Default
#> x = 1, 2, 3, ..., 6.
## x = 1, 2, 3, ..., 6.

# It will never output 1, 2, 3, 4, ..., 6
printf("x = %s.\n", hpaste(x, maxHead=4))
#> x = 1, 2, 3, 4, 5, 6.
## x = 1, 2, 3, 4, 5, 6.

# Showing the tail
printf("x = %s.\n", hpaste(x, maxHead=1, maxTail=2))
#> x = 1, ..., 5, 6.
## x = 1, ..., 5, 6.

# Turning off abbreviation
printf("y = %s.\n", hpaste(y, maxHead=Inf))
#> y = 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.
## y = 10, 9, 8, 7, 6, 5, 4, 3, 2, 1

## ...or simply
printf("y = %s.\n", paste(y, collapse=", "))
#> y = 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.
## y = 10, 9, 8, 7, 6, 5, 4, 3, 2, 1


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Adding a special separator before the last element
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Change last separator
printf("x = %s.\n", hpaste(x, lastCollapse=", and "))
#> x = 1, 2, 3, 4, 5, and 6.
## x = 1, 2, 3, 4, 5, and 6.



# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Backward compatibility with paste()
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
s1 <- hpaste(x, maxHead=Inf)
s2 <- paste(x, collapse=", ")
printf("s = %s.\n", s1);
#> s = 1, 2, 3, 4, 5, 6.
stopifnot(identical(s1, s2))

s1 <- hpaste('<', x, '>', maxHead=Inf)
s2 <- paste('<', x, '>', sep="", collapse=", ")
printf("s = %s.\n", s1);
#> s = <1>, <2>, <3>, <4>, <5>, <6>.
stopifnot(identical(s1, s2))

s1 <- hpaste(x, y, z, sep="/", maxHead=Inf)
s2 <- paste(x, y, z, sep="/", collapse=", ")
printf("s = %s.\n", s1);
#> s = 1/10/A, 2/9/B, 3/8/C, 4/7/D, 5/6/E, 6/5/F, 1/4/A, 2/3/B, 3/2/C, 4/1/D.
stopifnot(identical(s1, s2))

s1 <- hpaste(x, collapse=NULL, maxHead=Inf)
s2 <- paste(x, collapse=NULL)
stopifnot(identical(s1, s2))