Expressions enclosed by braces will be evaluated as R code. Long strings are broken by line and concatenated together. Leading whitespace and blank lines from the first and last lines are automatically trimmed.
glue_data(
.x,
...,
.sep = "",
.envir = parent.frame(),
.open = "{",
.close = "}",
.na = "NA",
.null = character(),
.comment = "#",
.literal = FALSE,
.transformer = identity_transformer,
.trim = TRUE
)
glue(
...,
.sep = "",
.envir = parent.frame(),
.open = "{",
.close = "}",
.na = "NA",
.null = character(),
.comment = "#",
.literal = FALSE,
.transformer = identity_transformer,
.trim = TRUE
)
[listish
]
An environment, list, or data frame used to lookup values.
[expressions
]
Unnamed arguments are taken to be expression
string(s) to format. Multiple inputs are concatenated together before formatting.
Named arguments are taken to be temporary variables available for substitution.
[character(1)
: ‘""’]
Separator used to separate elements.
[environment
: parent.frame()
]
Environment to evaluate each expression in. Expressions are
evaluated from left to right. If .x
is an environment, the expressions are
evaluated in that environment and .envir
is ignored. If NULL
is passed, it is equivalent to emptyenv()
.
[character(1)
: ‘\{’]
The opening delimiter. Doubling the
full delimiter escapes it.
[character(1)
: ‘\}’]
The closing delimiter. Doubling the
full delimiter escapes it.
[character(1)
: ‘NA’]
Value to replace NA
values
with. If NULL
missing values are propagated, that is an NA
result will
cause NA
output. Otherwise the value is replaced by the value of .na
.
[character(1)
: ‘character()’]
Value to replace
NULL values with. If character()
whole output is character()
. If
NULL
all NULL values are dropped (as in paste0()
). Otherwise the
value is replaced by the value of .null
.
[character(1)
: ‘#’]
Value to use as the comment
character.
[boolean(1)
: ‘FALSE’]
Whether to treat single or
double quotes, backticks, and comments as regular characters (vs. as
syntactic elements), when parsing the expression string. Setting .literal = TRUE
probably only makes sense in combination with a custom
.transformer
, as is the case with glue_col()
. Regard this argument
(especially, its name) as experimental.
[function]
A function taking three parameters code
, envir
and
data
used to transform the output of each block before, during, or after
evaluation. For example transformers see vignette("transformers")
.
[logical(1)
: ‘TRUE’]
Whether to trim the input
template with trim()
or not.
https://www.python.org/dev/peps/pep-0498/ and https://www.python.org/dev/peps/pep-0257/ upon which this is based.
name <- "Fred"
age <- 50
anniversary <- as.Date("1991-10-12")
glue('My name is {name},',
'my age next year is {age + 1},',
'my anniversary is {format(anniversary, "%A, %B %d, %Y")}.')
#> My name is Fred,my age next year is 51,my anniversary is Saturday, October 12, 1991.
# single braces can be inserted by doubling them
glue("My name is {name}, not {{name}}.")
#> My name is Fred, not {name}.
# Named arguments can be used to assign temporary variables.
glue('My name is {name},',
' my age next year is {age + 1},',
' my anniversary is {format(anniversary, "%A, %B %d, %Y")}.',
name = "Joe",
age = 40,
anniversary = as.Date("2001-10-12"))
#> My name is Joe, my age next year is 41, my anniversary is Friday, October 12, 2001.
# `glue()` can also be used in user defined functions
intro <- function(name, profession, country){
glue("My name is {name}, a {profession}, from {country}")
}
intro("Shelmith", "Senior Data Analyst", "Kenya")
#> My name is Shelmith, a Senior Data Analyst, from Kenya
intro("Cate", "Data Scientist", "Kenya")
#> My name is Cate, a Data Scientist, from Kenya
# `glue_data()` is useful in magrittr pipes
if (require(magrittr)) {
mtcars %>% glue_data("{rownames(.)} has {hp} hp")
# Or within dplyr pipelines
if (require(dplyr)) {
head(iris) %>%
mutate(description = glue("This {Species} has a petal length of {Petal.Length}"))
}}
#> Loading required package: magrittr
#> Loading required package: dplyr
#>
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#>
#> filter, lag
#> The following objects are masked from ‘package:base’:
#>
#> intersect, setdiff, setequal, union
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> 1 5.1 3.5 1.4 0.2 setosa
#> 2 4.9 3.0 1.4 0.2 setosa
#> 3 4.7 3.2 1.3 0.2 setosa
#> 4 4.6 3.1 1.5 0.2 setosa
#> 5 5.0 3.6 1.4 0.2 setosa
#> 6 5.4 3.9 1.7 0.4 setosa
#> description
#> 1 This setosa has a petal length of 1.4
#> 2 This setosa has a petal length of 1.4
#> 3 This setosa has a petal length of 1.3
#> 4 This setosa has a petal length of 1.5
#> 5 This setosa has a petal length of 1.4
#> 6 This setosa has a petal length of 1.7
# Alternative delimiters can also be used if needed
one <- "1"
glue("The value of $e^{2\\pi i}$ is $<<one>>$.", .open = "<<", .close = ">>")
#> The value of $e^{2\pi i}$ is $1$.