[Rd] question about an R idiom: eval()ing a quoted block

[Ben Bolker]

   In a few places in the R source code, such as the $initialize element 
of `family` objects, and in the body of power.t.test() (possibly other 
power.* functions), sets of instructions that will need to be run later 
are encapsulated by saving them as an expression and later applying 
eval(), rather than as a function. This seems weird to me; the only 
reason I can think of for doing it this way is to avoid having to pass 
back multiple objects and assign them in the calling environment (since 
R doesn't have a particularly nice form of Python's tuple-unpacking idiom).

   Am I missing something?

  cheers
    Ben


https://github.com/r-devel/r-svn/blob/eac72e66a4d2c2aba50867bd80643b978febf5a3/src/library/stats/R/power.R#L38-L52

https://github.com/r-devel/r-svn/blob/master/src/library/stats/R/family.R#L166-L171