[Rd] Where does L come from?

Hervé Pagès hp@ge@ @ending from fredhutch@org
Sun Aug 26 07:57:20 CEST 2018

On 08/25/2018 04:33 PM, Duncan Murdoch wrote:
> On 25/08/2018 4:49 PM, Hervé Pagès wrote:
>> The choice of the L suffix in R to mean "R integer type", which
>> is mapped to the "int" type at the C level, and NOT to the "long int"
>> type, is really unfortunate as it seems to be misleading and confusing
>> a lot of people.

I don't have stats about this so I take back the "lot".

> Can you provide any evidence of that (e.g. a link to a message from one 
> of these people)?  I think a lot of people don't really know about the L 
> suffix, but that's different from being confused or misleaded by it.
> And if you make a criticism like that, it would really be fair to 
> suggest what R should have done instead.  I can't think of anything 
> better, given that "i" was already taken, and that the lack of a decimal 
> place had historically not been significant.  Using "I" *would* have 
> been confusing (3i versus 3I being very different).  Deciding that 3 
> suddenly became an integer value different from 3. would have led to 
> lots of inefficient conversions (since stats mainly deals with floating 
> point values).

Maybe 10N, or 10n? I'm not convinced that 10I would have been
confusing but the I can easily be mistaken for a 1.


> Duncan Murdoch
>> The fact that nowadays "int" and "long int" have the same size on most
>> platforms is only anecdotal here.
>> Just my 2 cents.
>> H.
>> On 08/25/2018 10:01 AM, Dirk Eddelbuettel wrote:
>>> On 25 August 2018 at 09:28, Carl Boettiger wrote:
>>> | I always thought it meant "Long" (I'm assuming R's integers are long
>>> | integers in C sense (iirrc one can declare 'long x', and it being 
>>> common to
>>> | refer to integers as "longs"  in the same way we use "doubles" to mean
>>> | double precision floating point).  But pure speculation on my part, 
>>> so I'm
>>> | curious!
>>> It does per my copy (dated 1990 !!) of the 2nd ed of Kernighan & 
>>> Ritchie.  It
>>> explicitly mentions (sec 2.2) that 'int' may be 16 or 32 bits, and 
>>> 'long' is
>>> 32 bit; and (in sec 2.3) introduces the I, U, and L labels for 
>>> constants.  So
>>> "back then when" 32 bit was indeed long.  And as R uses 32 bit 
>>> integers ...
>>> (It is all murky because the size is an implementation detail and later
>>> "essentially everybody" moved to 32 bit integers and 64 bit longs as 
>>> the 64
>>> bit architectures became prevalent.  Which is why when it matters one 
>>> should
>>> really use more explicit types like int32_t or int64_t.)
>>> Dirk

Hervé Pagès

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