On Tue, Jun 23, 2020 at 11:26:27AM -0700, Michael Forney wrote: > Thanks for testing this out, Richard. > > On 2020-06-23, Richard Ipsum <richardip...@vx21.xyz> wrote: > > I don't feel qualified to criticise the overall design, but do we not still > > need a way to specify whether traversal should be pre-order or post-order? > > I figure this is what DIRFIRST was for right? > > The effective traversal order can be controlled by structuring your > recursor function to call recursedir() at the beginning or end. > > DIRFIRST was only useful because a top-level directory was handled > specially by recurse. Normally, recurse() does not "visit" its > argument at all, only its children. For D/f, the call structure was > something like this for DIRFIRST: > [snip] > > As you can see, the DIRFIRST flag is only used at the toplevel for > bootstrapping. In other cases, it is ignored, since the function is > just structured differently depending on whether it needs the children > processed first or last: > > fn(D) > do something with D > recurse(D) > > or > > fn(D) > recurse(D) > do something with D
Makes sense, thanks for the explanation! Thanks, Richard
