[rkward-tracker] [ rkward-Feature Requests-1810061 ] Speed up assignments in globalenv()

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Feature Requests item #1810061, was opened at 2007-10-09 12:03
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Category: None
Group: None
Status: Open
Priority: 5
Private: No
Submitted By: Thomas Friedrichsmeier (tfry)
Assigned to: Nobody/Anonymous (nobody)
Summary: Speed up assignments in globalenv()

Initial Comment:
Assignments inside globalenv() are slow due to modification detection. Run this code:

# first create an object in a single command
x <- 1

# now assign to it many times
for (i in 1:100000) x <- 2

# in contrast, try this:
local ({for (i in 1:100000) x <- 2; x <<- x})

The latter is tremendously faster. In a plain R session, there is no such difference.

Probably we can improve on this by implementing .rk.watch.symbol(), and esp. the watch function created by .rk.make.watch.f() in C, and also fine-tuning it in the process.


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