getPropagateChanges: Determine which expressions to update when a variable changes
Description
This function allows us to determine which subsequent expressions
in the document need to be evaluated when a variable is assigned a new
value. This is the "opposite" of determining on which variables a
given variable depends; this is for identifying which variables and
expressions need to be updated when a variable changes.
This is of use when propogating changes to dependent expressions.
information extracted from the expressions about the
inputs to each expressions. See getInputs.
recursive
a logical value that controls whether to work
recursively on the expressions
index
a logical value which controls whether we return the
indices of the expressions that would need to be evaluated based on
the change to the variable var, or if index is
FALSE, we return the expressions themselves.
envir
the environment in which to evaluate the expressions
eval
a logical value controlling whether we evaluate the
expressions or just return them
verbose
a logical value that controls whether we output
information about the expressions and their evaluation on the R console.
Value
This returns
either the expressions or the indices of the expressions
that need to be re-evaluated due to a change in var.
# NOT RUN {sc = readScript(system.file("samples", "formula.R", package = "CodeDepends"))
info = getInputs(sc)
getPropagateChanges("x", sc, info = info)
getPropagateChanges("y", sc, info = info)
# }