floating point syntax

Robert Virding <>
Mon Apr 19 23:16:02 CEST 2010


IIRC it was probably more that we/I just didn't see the need to be
able to write the shortened forms. It isn't that it is much extra you
have to write. :-)

Robert

On 16 April 2010 18:26, Michael Turner <> wrote:
>
> I guess this has something to do with the fact that a period is also a
> terminator in Erlang syntax.  If you allowed "1." as a legal float,
> for example, you're permitting this:
>
>  fp1() -> 1..
>
> And with
>
>  f() -> 1.e5;
>
> you need a bit more token lookahead (since "e5" could be seen as the
> start of a new function).  My guess, as I say.
>
> -michael turner
>
> On 4/15/2010, "Robert Virding" <> wrote:
>
>>Yes, it is supposed to be like that, no, it is not a bug. Floats
>>consist of both parts before and after the decimal point and an
>>optional exponent.
>>
>>Robert
>>
>>On 15 April 2010 16:21, Anthony Shipman <> wrote:
>>> The reference manual says "There are two types of numeric literals, integers
>>> and floats. Besides the conventional notation,..."
>>>
>>> But what is the "conventional notation" exactly? I find that this fails:
>>> 19> io_lib:fread("~f", "1e+2").
>>> {error,{fread,float}}
>>>
>>> Also
>>> 1.e+2 fails
>>> 1 ? ? fails
>>> 1. ? ?fails
>>> 1.0 ? succeeds
>>> .1 ? ?fails
>>> 0.1 ? succeeds
>>> 1.0e+2 succeeds
>>>
>>> Is it supposed to be like that or is there a bug?
>>>
>>> --
>>> Anthony Shipman ? ? ? ? ? ? ? ? ? ?Mamas don't let your babies
>>>  ? ? ? ? ? ? ? ? ? grow up to be outsourced.
>>>
>>> ________________________________________________________________
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>>
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