Result of 'seq' doesn't use compact internal representation
On 28/04/2018 11:11 PM, Suharto Anggono Suharto Anggono via R-devel wrote:
.Internal(inspect(1:10))
@300e4e8 13 INTSXP g0c0 [NAM(3)] 1 : 10 (compact)
.Internal(inspect(seq(1,10)))
@3b6e1f8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,...
system.time(1:1e7)
user system elapsed
0 0 0
system.time(seq(1,1e7))
user system elapsed
0.05 0.00 0.04
It seems that result of function 'seq' doesn't use compact internal representation. However, looking at the code of function 'seq.default', seq(1,n) produces 1:n. What is going on?
It looks like it is related to using compiled or interpreted code: > library(gtools) > seq2 <- unByteCode(seq.default) > .Internal(inspect(seq.default(1,10))) @7fa53847dcd8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,... > .Internal(inspect(seq2(1,10))) @7fa537fa0bf0 13 INTSXP g0c0 [NAM(3)] 1 : 10 (compact) Duncan Murdoch
h <- seq.default environment(h) <- .GlobalEnv library(compiler) enableJIT(0)
[1] 3
.Internal(inspect(h(1,10)))
@375ade8 13 INTSXP g0c0 [NAM(3)] 1 : 10 (compact) A non-byte-compiled version of function 'seq.default' can produce object that uses compact internal representation.
sessionInfo()
R version 3.5.0 (2018-04-23) Platform: i386-w64-mingw32/i386 (32-bit) Running under: Windows XP (build 2600) Service Pack 3 Matrix products: default locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] compiler stats graphics grDevices utils datasets methods [8] base
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