[Swift-devel] A new use case for the persistent swift server

[wilde at mcs.anl.gov]

Mihael, as the Swift R interface progresses I realize we have another use case to consider for the persistent Wwift service:

- run the same script repeatedly, from different directories (perhaps with different arguments)

- since the script doesn't change, we can run a pre-compiled version: no need to regenerate the myscript.xml and myscript.kml files.

Can this be readily handled by the code you have underway to do multiple script executions from a single Swift invocation?

For the R code, the script (for now) is always the same simple foreach loop that executes an R list apply() function in parallel:

swiftapply.swift:

type file;
type RFile;

app (RFile result, file stout, file sterr) RunR (RFile rcall)
{
  RunR @rcall @result stdout=@stout stderr=@sterr;
}

RFile rcalls[]  <simple_mapper; prefix="cbatch.", suffix=".Rdata", padding=0>;
RFile results[] <simple_mapper; prefix="rbatch.", suffix=".Rdata", padding=0>;
file  stout[]   <simple_mapper; prefix="stdout.", suffix=".txt", padding=0>;
file  sterr[]   <simple_mapper; prefix="stderr.", suffix=".txt", padding=0>;

foreach c, i in rcalls {
  (results[i],stout[i], sterr[i]) = RunR(c);
}

- Mike