samer@44: % map_fields - Apply function to all member fields of structure
samer@44: %
samer@44: % map_fields :: 
samer@44: %    (A->B)              ~'function from As to Bs',
samer@44: %    struct(fields(N,A)) 
samer@44: % -> struct(fields(N,B)).
samer@44: %
samer@44: % fields(N,A) denotes a list of struct field type declarates with
samer@44: % names from list N and types all equal to A, eg
samer@44: %    fields({'a','b','c'},real) == {a::real, b::real, c::real}.
samer@44: 
samer@44: function y=map_fields(fn,x)
samer@44: 	y=foldl(@(s,f)setfield(s,f,fn(s.(f))),x,fields(x));