[Oberon] Fwd: IDE with integrated source level debuggerandLuaJIT VM running the Oberon System

[Paul Reed]

Hi Michael,

> As the directory index in the Oberon filesystem is a B-Tree, the prefix
> is used to optimize the scanning to only look at pages that may contain
> the given prefix.
...
> Implementations of FileDir.Enumerate are free to ignore the prefix, as
> the only caller in System.Mod will validate the whole filename
> afterwards anyway.

But other clients might not - rather, expecting that Enumerate is 
implemented as in the book, surely?

"The set of visited elements can be restricted by specifying a string 
which is to be a prefix to all enumerated names"

https://inf.ethz.ch/personal/wirth/ProjectOberon/PO.System.pdf, p.100

Cheers,
Paul