Construct strings with color — glue

The crayon package defines a number of functions used to color terminal output. glue_col() and glue_data_col() functions provide additional syntax to make using these functions in glue strings easier.

Using the following syntax will apply the function crayon::blue() to the text 'foo bar'.

{blue foo bar}

If you want an expression to be evaluated, simply place that in a normal brace expression (these can be nested).

{blue 1 + 1 = {1 + 1}}

If the text you want to color contains, e.g., an unpaired quote or a comment character, specify .literal = TRUE.

Usage

glue_col(..., .envir = parent.frame(), .na = "NA", .literal = FALSE)

glue_data_col(.x, ..., .envir = parent.frame(), .na = "NA", .literal = FALSE)

Arguments

...

[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.

For glue_data(), elements in ... override the values in .x.

.envir

[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().

.na

[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.

.literal

[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.

.x

[listish]
An environment, list, or data frame used to lookup values.

Value

A glue object, as created by as_glue().

Examples

library(crayon)

glue_col("{blue foo bar}")
#> foo bar

glue_col("{blue 1 + 1 = {1 + 1}}")
#> 1 + 1 = 2

glue_col("{blue 2 + 2 = {green {2 + 2}}}")
#> 2 + 2 = 4

white_on_black <- bgBlack $ white
glue_col("{white_on_black
  Roses are {red {colors()[[552]]}},
  Violets are {blue {colors()[[26]]}},
  `glue_col()` can show \\
  {red c}{yellow o}{green l}{cyan o}{blue r}{magenta s}
  and {bold bold} and {underline underline} too!
}")
#> Roses are red,
#> Violets are blue,
#> `glue_col()` can show   colors
#> and bold and underline too!

# this would error due to an unterminated quote, if we did not specify
# `.literal = TRUE`
glue_col("{yellow It's} happening!", .literal = TRUE)
#> It's happening!

# `.literal = TRUE` also prevents an error here due to the `#` comment
glue_col(
  "A URL: {magenta https://github.com/tidyverse/glue#readme}",
  .literal = TRUE
)
#> A URL: https://github.com/tidyverse/glue#readme

# `.literal = TRUE` does NOT prevent evaluation
x <- "world"
y <- "day"
glue_col("hello {x}! {green it's a new {y}!}", .literal = TRUE)
#> hello world! it's a new day!