collect_asigned_symbols_in_expression: Extracts all the symbols that appear on the left-hand side of...
In mailund/foolbox: Function Manipulation Toolbox

Description Usage Arguments Details Value Functions

Since R does not require that we declare local variables, and since the variables that are assigned to a local scope depend on the runtime execution of functions, we cannot determine with any certainty which variables will be assigned to in any given scope at any given program point. So the best we can do is figure out which variables are potentially assigned to. Which is what this function does.

collect_assigned_symbols_in_expression(expr, env, params = list(),
  topdown = list())

collect_assigned_symbols_in_function(fun, topdown = list())

`expr`	The expression to analyse
`env`	Environment in which to look up symbols.
`params`	Parameters for the function being analysed (if these are needed).
`topdown`	Information to pass top-down in the traversal.
`fun`	The function whose body we should analyse

The collect_assigned_symbols_in_function() function reformats the collected data into a character vector, removes duplications, and remove the formal parameters of the function from the list, so those are not considered local variables (rather, they are considered formals and presumably handled elsewhere as such).

A list containing the symbols that were assigned to.