super is a fork / reimplementation of the glue package with a focus on efficiency and simplicity at a cost of flexibility.
super::glue() takes only two arguments: A character string that is used as
a template and an environment to look up the embraced inputs. There is no
option to change the delimiters from being a pair of braces (e.g. {name}).
Embraced inputs are always looked up in the provided environment (akin to
calling get()) and are not evaluated. This is similar to glue::glue_safe()
and glue::glue_data_safe() but note that this is not the default behaviour
of glue::glue().
super::glue() does not trim inputs. Instead this is done by either the
function super::glut() or explicitly by glue(trim(x)).
super::glue() returns an unclassed character vector whereas glue::glue()
returns a <glue> object and provides a variety of methods to work on that
object.
At present, super::glue() does not provide any allowance for different
handling of NA and NULL values, instead following the behaviour of
paste().
Recycling of embraced arguments currently follows standard R recycling rules where the arguments will be recycled to the length of the longest one.
glue::glue() arguments (and their associated behaviours) .comment,
.literal and .transformer are not implemented.
library(super)
bar <- "baz"
glue("foo{bar}")
#> [1] "foobaz"
dat <- head(cbind(car = rownames(mtcars), mtcars))
glue("{car} does {mpg} mpg.", dat)
#> [1] "Mazda RX4 does 21 mpg." "Mazda RX4 Wag does 21 mpg."
#> [3] "Datsun 710 does 22.8 mpg." "Hornet 4 Drive does 21.4 mpg."
#> [5] "Hornet Sportabout does 18.7 mpg." "Valiant does 18.1 mpg."
name <- "Fred"
age <- 50
anniversary <- as.Date("1991-10-12")
out <- glut("
My name is {name},
my age next year is {age},
my anniversary is {anniversary}.
")
cat(out)
#> My name is Fred,
#> my age next year is 50,
#> my anniversary is 1991-10-12.
Over embraced arguments
head(glue("Item {LETTERS}"))
#> [1] "Item A" "Item B" "Item C" "Item D" "Item E" "Item F"
But not over input strings (yet)
glue(letters)
#> `x` must be a character vector of length <= 1.
library(microbenchmark)
bar <- "baz"
bob <- 20
microbenchmark(
sprintf = sprintf("foo%s %d", bar, bob),
paste0 = paste0("foo", bar, " ", bob),
super = super::glue("foo{bar} {bob}"),
glue = as.character(glue::glue_safe("foo{bar} {bob}", .trim = FALSE)),
unit = "relative",
check = "identical"
)
#> Unit: relative
#> expr min lq mean median uq max neval
#> sprintf 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 100
#> paste0 2.782214 2.581320 2.489924 2.406657 2.151365 4.269248 100
#> super 8.745917 8.348631 7.412320 7.793777 6.917494 4.105864 100
#> glue 73.203267 66.622383 56.658633 60.714906 52.965261 20.190018 100
dat <- head(cbind(car = rownames(mtcars), mtcars))
microbenchmark(
sprintf = with(dat, sprintf("%s does %.3g mpg.", car, mpg)),
paste0 = with(dat, paste(car, "does", mpg, "mpg.")),
super = super::glue("{car} does {mpg} mpg.", dat),
glue = as.character(glue::glue_data(dat, "{car} does {mpg} mpg.")),
unit = "relative",
check = "identical"
)
#> Unit: relative
#> expr min lq mean median uq max neval
#> sprintf 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 100
#> paste0 1.639398 1.605489 1.536967 1.556278 1.499879 1.063850 100
#> super 2.707324 2.640144 2.575891 2.587211 2.470759 3.576688 100
#> glue 17.022445 16.375381 15.450827 15.581622 14.816336 10.348410 100
microbenchmark(
super = super::glut("
My name is {name},
my age next year is {age},
my anniversary is {anniversary}.
"),
glue = as.character(glue::glue("
My name is {name},
my age next year is {age},
my anniversary is {anniversary}.
")),
unit = "relative",
check = "identical"
)
#> Unit: relative
#> expr min lq mean median uq max neval
#> super 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 100
#> glue 4.150907 3.962442 3.808781 3.871885 3.847039 1.610143 100
For larger input with both glue::glue() and super::glue(), the performance
becomes dominated by the internally constructed call to paste0(), hence the
convergence observed below.
bar <- rep("baz", 1e5)
microbenchmark(
sprintf = sprintf("foo%s %d", bar, bob),
paste0 = paste0("foo", bar, " ", bob),
super = super::glue("foo{bar} {bob}"),
glue = as.character(glue::glue_safe("foo{bar} {bob}", .trim = FALSE)),
unit = "relative",
check = "identical"
)
#> Unit: relative
#> expr min lq mean median uq max neval
#> sprintf 1.258421 1.232784 1.245969 1.235738 1.231066 1.1916430 100
#> paste0 1.000000 1.000000 1.000000 1.000000 1.000000 1.0000000 100
#> super 1.018565 1.000552 0.997944 1.000508 1.000729 0.9185109 100
#> glue 1.145637 1.142098 1.145423 1.142665 1.130846 1.1326411 100