[erlang-questions] Reading, Learning, Confused
Sat Jul 19 18:59:14 CEST 2008
Edwin Fine wrote:
> of guards, it is guaranteed that leaving out the evaluation of one or
> more guards will not change the state of the program.
I don't think that's quite right.
f(X) when (X == 0) or ((1 / X) > 2) ->
"does not return for zero X";
f(X) when (X == 0) orelse ((1 / X) > 2) ->
"does return for zero X".
I might be misunderstanding here, but I understand that an "abrupt
return" from a calculation in a guard is treated the same as "false".
So in the first case, when X is 0, the guard evaluates to false, because
1/X errors out, making the entire expression false.
In the second case, 1/X isn't evaluated when X==0, making the entire
It does seem like the documentation is wrong. I just tried the above
fragment and it printed "does return" as its answer.
Darren New / San Diego, CA, USA (PST)
Helpful housekeeping hints:
Check your feather pillows for holes
before putting them in the washing machine.
More information about the erlang-questions