setup.mcache( envir, fpath, refs)mcache attribute of envir, by defaultenvir for each element in refs. The active binding for an object myobj will be a function which keeps the real data in its own environment, reading and writing it as required. Writing a new value will give attr( envir, "mcache")[ "myobj"] a negative sign. This signals that the "obj*.rda" file needs updating, and the next Save (or move or cd) command will do so. [The "*" is the absolute value of attr( envir, "mcache")[ "myobj"].] One wrinkle is that the "real data" is initially a promise created by delayedAssign, which will fetch the data from disk the first time it is needed.mlazy, makeActiveBinding