Displaying 1 result from an estimated 1 matches for "4eeb0008".
2013 Mar 22
1
Why does typeof() modify an object's "named" field?
Hello,
Doing typeof() on an object appears to reset the "named" field in its
sxpinfo header to 2, which can change the way that subsequent
subassignment operations are carried out:
X <- 1:5e7
.Internal(inspect(X))
# @4eeb0008 13 INTSXP g0c7 [NAM(1)] (len=50000000, tl=0) 1,2,3,4,5,...
system.time(X[1] <- 9L)
# user system elapsed
# 0 0 0
typeof(X)
.Internal(inspect(X))
# @4eeb0008 13 INTSXP g1c7 [MARK,NAM(2)] (len=50000000, tl=0) 9,2,3,4,5,...
system.time(X[2] <- 9L)
# user system elaps...