Evaluate expressions
Usage
eval_dirty(expr, env = parent.frame(), data = NULL, quoted = TRUE)Arguments
- expr
R expression or 'rlang' quo
- env
environment to evaluate
- data
dataframe or list
- quoted
Is the expression quoted? By default, this is
TRUE. This is useful when you don't want to use an expression that is stored in a variable; see examples
Details
eval_dirty uses base::eval() function to evaluate
expressions. Compare to rlang::eval_tidy, which won't affect original
environment, eval_dirty causes changes to the environment. Therefore
if expr contains assignment, environment will be changed in this case.
Examples
env = new.env(); env$a = 1
rlang::eval_tidy(quote({a <- 111}), env = env)
print(env$a) # Will be 1. This is because eval_tidy has no side effect
#> [1] 1
eval_dirty(quote({a <- 111}), env)
print(env$a) # 111, a is changed
#> [1] 111
# Unquoted case
eval_dirty({a <- 222}, env, quoted = FALSE)
print(env$a)
#> [1] 222