Catmandu::Fix::add_field(3) add or change the value of a HASH key or ARRAY index


Contrary to "set_field", this will create the intermediate structures if they are missing.


# Add a new field 'foo' with value 2
add_field(foo, 2)
# Change the value of 'foo' to 'bar 123'
add_field(foo, 'bar 123')
# Create a deeply nested key
add_field(my.deep.nested.key, hi)