Helper function to infer target from expression and environment

parse_env_subset(
  expr,
  envir = parent.frame(),
  substitute = TRUE,
  is_variable = TRUE
)

Arguments

expr

An expression.

envir

An environment.

substitute

If TRUE, then the expression is base::substitute():ed, otherwise not.

is_variable

(logical) If TRUE and an element name is specified, then the name is checked to be a valid variable name.

Value

A named list with elements:

envir

An environment (defaults to argument envir)

name

A character vector. ...

op

...

subset

A list of NULL. ...

idx

An integer vector or NULL. ...

exists

A logical vector of length length(idx) with TRUE and FALSE values.

code

The deparsed expression expr coerced to a single character string.