Nested structure access using dynamic fieldnames

Question

I'd like to achieve the following using dynamic fieldnames instead of setfield:

Say a struct 'myStruct' has a set of nested structures, i.e.

myStruct.a.b.c = 0
myStruct.a.d = 0
myStruct.a.e.f.g = 0

I want to be able to flexibly set the leaf structure values as follows:

fields = {'a', 'b', 'c'}
paramVal = 1
setfield(myStruct, fields{:}, paramVal)

This works using setfield. Is there a syntax that will do this using dynamic fieldnames? The following obviously doesn't work because the fieldname needs to be a string not an array, but demonstrates what I want:

myStruct.(fields{:}) = 0

Which would be equivalent to:

myStruct.('a').('b').('c') = 0

Answer 1

Recursive solution without eval, ripped from one of my old utility functions:

function s = setsubfield(s, fields, val)

if ischar(fields)
    fields = regexp(fields, '\.', 'split'); % split into cell array of sub-fields
end

if length(fields) == 1
    s.(fields{1}) = val;
else
    try
        subfield = s.(fields{1}); % see if subfield already exists
    catch
        subfield = struct(); % if not, create it
    end
    s.(fields{1}) = setsubfield(subfield, fields(2:end), val);
end

I guess the try/catch can be replaced with if isfield(s, fields{1}) ..., I don't remember why I coded it like that.

Usage:

>> s = struct();
>> s = setsubfield(s, {'a','b','c'}, 55);
>> s = setsubfield(s, 'a.b.d.e', 12)
>> s.a.b.c
ans =
    55
>> s.a.b.d.e
ans =
    12