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.

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

Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
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E-mail: hpa...@fredhutch.org
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