Resolve Macro Variables In A Text

Variables written with a leading "&" inside a text will be resolved into the character or numeric expression the corresponding object is holding.

Usage

macro(text)

apply_macro(character_vector)

Arguments

text

A text containing macro variables to resolve.

character_vector

A vector containing multiple character expressions in which to resolve macro variables.

Value

macro(): Returns a character.

apply_macro(): Returns a character vector.

Details

Macro variables in 'SAS' can be set up with %Let and can act as global accessible variables. This in itself is nothing special to 'R' because basically every object created outside a function is a global variable.

To use these global objects within a text one has to use e.g. paste0("The current year is: ", year). With the macro function one can write it like this: macro("The current year is &year").

So where is the benefit? If implemented within a function, a parameter like "title" or "footnote" in the tabulation functions, can resolve these variables without the need of another function. You can just pass the character expression "The current year is &year" and the implementation inside the function resolves the macro variable directly in place.

See also

Functions that can make use of macro variables: any_table(), frequencies(), crosstabs(), export_with_style(), summarise_plus(), transpose_plus()

Within the tabulation functions titles, footnotes, var_labels and stat_labels can resolve macros. Additionally they can be used in the any_table() rows and columns parameter, in the summarise_plus() types parameter and in the transpose_plus() pivot parameter.

Examples

# Resolving macro variable in single character
year <- 2026

text <- macro("The current year is &year")

# You can also combine multiple macro variables
some_variable <- "current"
current2026   <- "The current year is"

text_combi <- macro("&&some_variable&year &year")

# Resolving macro variable in character vector
char_vector <- c("The current year is &year",
                 "The &some_variable year is &year",
                 "&&some_variable&year &year")

text_vector <- apply_macro(char_vector)