Re: Real numbers with Janus/Ada

[jans@mako.UUCP (Jan Steinman)]

In article <245@gumby.UUCP> g-frank@gumby.UUCP writes, quotes:
>> I seemed to recall that Janus/Ada besides lacking all the features
>> mentioned before, also lacks Float numbers (or real numbers).
>
>According to their literature, Janus/Ada lacks "based real numbers."
>What the heck is that?  The term doesn't appear in Gehani.  I do think
>the language handles floats.

There seems to be some confusion here.  A real number can be either a
"fixed point type" or "floating point type", both of which are subtypes of
the anonymous predefined type "universal_real".  (LRM language is in double
quotes)  The mentioned 'based real numbers' sounds like the method used in Ada
to specify real literals in arbitrary radix, something few languages offer.
(When was the last time you needed a number like 16#-F.EDCBA987654#E32?)  I
would assume that Janus/Ada supports floating point operations in ordinary
base 10 representations.

>... The term doesn't appear in Gehani....

Don't mess with popular books for questions like this.  GPO will send you
ANSI/MIL-STD-1815A ("Language Reference Manual", or commonly, LRM") for a mere
$8.00.  It's not light reading, but is precise, concise, and makes K&R look
like "Dick and Jane" in its completeness.  The only other I'd recommend is
"Software Engineering With Ada", Grady Booch.

References: LRM 2.4.2-5, 3.5.6-5, 3.5.7-4
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