[Swift-user] many-to-one mapping

Neil Best nbest at ci.uchicago.edu
Mon Dec 10 13:58:24 CST 2012

On Fri, Dec 7, 2012 at 3:21 PM, Mihael Hategan <hategan at mcs.anl.gov> wrote:
> On Fri, 2012-12-07 at 15:08 -0600, Neil Best wrote:
>> On Fri, Dec 7, 2012 at 2:35 PM, Mihael Hategan <hategan at mcs.anl.gov> wrote:
>> >
>> > foreach {
>> >    string m = @strcat(...);
>> >    file[] foo <...;..., match = m,...>;
>> > }
>> >
>> Shouldn't m also be an array?
> It's the pattern, so I'm guessing no.

I think there is a disconnect here because in my scenario there would
have to be a different regex for each year.  I need to match the
annual subset of all inputs (which span many years) to the
corresponding year.

Similarly the members of foo[] would have to be different for each
year.  I called it foo originally because I was treating it like a
throw-away.  Essentially what I need is a list of lists that maps
years (the loop variable) to subsets of files from nc1[].  I'm not
sure whether Swift needs an actual mapping of these files or if
passing the long string that is the concatenation of all of their
names to the leaf app is adequate.

So now I am doing this:

app (file n1) cdo( string op, string ifiles) {
  cdo op ifiles @n1;

file annual[]<simple_mapper;

string m[];

foreach year in [1979:2011] {
  m[ year] = @strcat( "^(data/nc/", year, "../narr-a_221_", year,
  file foo[]<structured_regexp_mapper;
    source= nc1,
    match= m[ year],
    transform= "\\1">;
  annual[ year]= cdo( "-O mergetime", @filename( foo));

where nc1 is a mapped array of files from a previously successful
Swift run, so the processing statements are commented out.

I suspect that the files in foo[] need to be mapped, not just have
their names passed as a concatenated string to the app, which brings
me back to the opening question: how to do a many to one mapping,
especially in the context of a looping parameter.  I hope I am asking
the right question, but I would not be surprised if something salient
about Swift semantics is eluding me.  Thanks.

More information about the Swift-user mailing list