macro (version 0.1.5)

symput: Assign a Variable in the Macro Symbol Table

Description

The symput function assigns the value of a macro variable from regular R code.

Usage

symput(x, value = NULL)

Value

The macro name, invisibly.

Arguments

x

The name of the macro variable to assign, passed as a quoted string with no leading ampersand or trailing dot ("."). The leading ampersand will be added automatically by the function. This parameter is required.

value

The value of the macro variable to assign. Value will be converted to a character string. This parameter is not required. If the value parameter is not supplied, the variable will be removed from the symbol table.

See Also

msource()

Other symtable: print.symtable(), symclear(), symget(), symtable()

Examples

library(macro)

# Get path to demo macro program
src <- system.file("extdata/Demo3.R", package = "macro")

# Display source code
# - This is the macro input code
cd <- readLines(src)
cat(paste(cd, "\n"))
# #% Determine appropriate data path
# #%if ("&env." == "prod")
#   #%let pth <- /projects/prod/data
# #%else
#   #%let pth <- /projects/dev/data
# #%end

# Set env macro variable using symput()
symput("env", "prod")

# Macro Execute Source Code
# - set clear to FALSE to so "env" value is not removed
msource(src, echo = FALSE, clear = FALSE)

# View "pth" macro variable
res <- symget("pth")

# View results
# - Path is set to the "prod" value
res
# [1] "/projects/prod/data"