[Swift-user] swift syntax problem (please ignore the previous one )

[Ben Clifford]

You can use some code like the below. This uses the simple mapper to 
generate a new filename for otherfile, based on substituting "foo" for 
"hello".

type messagefile;

app (messagefile t) greeting() { 
    echo "Hello, world!" stdout=@filename(t);
}

messagefile outfile <"/tmp/hello.txt">;
messagefile otherfile 
<single_file_mapper;file="/"+ at regexp(@filename(outfile),"hello","foo")>;

otherfile = greeting();