Where are usages like "== 2L" documented?

Patrick reminded me that it's also in The R Inferno, another document that I
need to read again.

So now, a more particular semi-question:

x <- 1L
y <- 1
z <- 1.0

class(x) # integer
class(y) # numeric
class(z) # numeric
NB: identical(x, y) is TRUE, so they behave the same.
x == 1
x == 1L
y == 1
z == 1 # all test TRUE

Just to clarify, I think the steps above prove it, but *in a test* like x ==
1 the test is for the contents, not the storage mode, not for a combination
of storage mode and contents.
Not really: the operands are coerced to a common type and then tested 
for equality.  From the help page for "=="

      If the two arguments are atomic vectors of different types, one is
      coerced to the type of the other, the (decreasing) order of
      precedence being character, complex, numeric, integer, logical and
      raw.
So... The reason for defining the notion of "L" is smaller storage space,
and more generally, for use anytime one wants explictly an integer for
whatever reason?  Are there other reasons, for instance, ways it saves lines
of code?
It avoids coercion.  The test x == 1 requires x to be coerced from 
integer to double, and foo[1] requires '1' to be coerced from double 
to integer.  There is little if any gain in storage space for small 
integer vectors over small double vectors, but all those coercions can 
create a lot of new objects which need to be garbage-collected.

Also, 2L is simpler to write and to read than as.integer(2) (and 
avoids a funtion call and a coercion).
Bryan
*************
Bryan Hanson
Acting Chair
Professor of Chemistry & Biochemistry
DePauw University, Greencastle IN USA

On 11/17/09 4:20 AM, "Patrick Burns" <pburns at pburns.seanet.com> wrote:

'The R Inferno' page 75.

Patrick Burns
patrick at burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of "The R Inferno" and "A Guide for the Unwilling S User")

Bryan Hanson wrote:
Gurus:

I keep seeing other people?s code that contain ideas like

If (x == 2L)
X[-1L]
X - 1L

I have some idea of what?s going on, but where is the use of concepts like
?2L? documented?

Thanks, Bryan
*************
Bryan Hanson
Acting Chair
Professor of Chemistry & Biochemistry
DePauw University, Greencastle IN USA

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Where are usages like "== 2L" documented?

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