[erlang-questions] Reading, Learning, Confused

[Edwin Fine]

Sean,

I think it's historical. "orelse" and "andalso" were added to the language
later. I would also be inclined to use the short-circuit ones, but I don't
find myself writing a lot of code that uses "and" and "or" anyway. I might
have written your example as

f(X) when X == 0; 1/X < 2 ->

which gets evaluated from left to right.

On Sat, Jul 19, 2008 at 11:05 AM, Sean Allen <sean@REDACTED>
wrote:

>
> On Jul 19, 2008, at 10:55 AM, Edwin Fine wrote:
>
>  I cannot imagine of any situation where or and orelse work the same and
>> reinstalling changes that. Please could you paste your exact code and shell
>> session, showing the problem? Also, which version of Erlang are you using?
>>
>
> ok i reinstalled and:
>
> Eshell V5.5.5  (abort with ^G)
> 1> X = 0.
> 0
> 2> (X == 0 ) or (1/X > 2).
>
> =ERROR REPORT==== 19-Jul-2008::11:02:12 ===
> Error in process <0.30.0> with exit value:
> {badarith,[{erlang,'/',[1,0]},{erl_eval,do_apply,5},{erl_eval,expr,5},{erl_eval,expr,5},{shell,exprs,6},{shell,eval_loop,3}]}
>
> ** exited: {badarith,[{erlang,'/',[1,0]},
>                      {erl_eval,do_apply,5},
>                      {erl_eval,expr,5},
>                      {erl_eval,expr,5},
>                      {shell,exprs,6},
>                      {shell,eval_loop,3}]} **
> 3> (X == 0 ) orelse (1/X > 2).
> true
>
>
> which makes a lot more sense. i have no idea why or and orelse where the
> same before.
>
> which leaves the question ( after answering a lot of confusion )...
>
> why would you want to use
>
> or
>
> instead of
>
> orelse
>
> ?
>
>
>


-- 
The great enemy of the truth is very often not the lie -- deliberate,
contrived and dishonest, but the myth, persistent, persuasive, and
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John F. Kennedy 35th president of US 1961-1963 (1917 - 1963)
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