BTW, the same problem can occur with Little Snitch if you use AppleJack. Some errant kext file will kill your system.

Also, Apple advises against using Application Enhancer for the same startup reason.

The reason I installed python 2.6 was to support antialiased fonts in Leo. Other than that, I am a casual python user, and content to go with the version distributed with the OS. I understand python 2.6 will be the default in Ubuntu in another six months or so, when Jaunty Jackelope is released.

recursion in Erlang works hand in hand with single-assignment variables, no?

Without this explicit behavior, e.g. with an implicit search of the current directory, would it be less astonishing to search the current directory before, or after, the CDPATH?

There are a number of other reasons for this including keeping people from walking a directory tree in a restricted shell and such.

If you look in “man bash” you will see the sample value is ‘.:~:/usr’, and I believe that in most cases checking the current directory first is the best behavior, it prevents masking of directory classes. For instance if you had ‘CDPATH=/usr:.’ and you were in /usr/local then ‘cd bin’ would take you to /usr/bin instead of the expected /usr/local/bin, and so on.

Note that this example is extemporaneous, so it may be buggy (I don’t have erlang here to test this. (Note that I use ‘ok’ and ‘error’ for example error checking as well)

[code]
% Empty lists are bad, there is no minimum to no-value/NULL
min([]) -> {error, []};
% A simple identity operation for completeness
min({ok, X}) -> {ok, X};
% A well defined entry point, e.g. the “normal” case
min([H|T]) -> min({ok, H},T).

% fixed point of recursion, list is empty, the answer is B
min({ok,B},[]) -> {ok,B};
% the only test in the whole module, the guard selects the new minimum value here
min({ok,B},[H|T]) when B > H -> min({ok,H},T);
% By default the old B is less than the head, so we don’t care about it any more
min({ok,B},[_H|T]) -> min({ok,B},T).

% helper for doing “X = 5 * value(min(List))” and (drop ‘ok’ after check, return V)
value({ok,V}) -> V.
[/code]

Note that since the very last call in every branch that recurses, a call to the recursion, the compiler is free to not save up intermediate values in a call stack they way it would have to in the case of smaller(H,min(T)) since in that case min is evaluated to return a value before smaller can be called [arguments evaluate first].

So we use matching _and_ guards as the mechanism to do recursion “right” where matching is primary, but guards disambiguate “identical” matches, so fn(X) is unambiguous where things like fn(X,Y) and another fn(X,Y) must rely on guarding.

As a general rule, you should: Match before Guard, Guard before Test-with-if/case.