Umple E013 Non Immutable Association
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E013 Non Immutable Association
Umple semantic error reported when an immutable class is defined as having an association to a non-immutable class.
By definition, an immutable class can't change state, so it can't have an association that can change state or an association to a class that can change state.
Example
// The following example generates
// the error message
class X {
Integer x;
}
class Y {
String s;
immutable;
0..1 -> 0..1 X;
}
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Solution to The Above So the Message No Longer Appears
// One way to solve this is to make
// the association point to
// another immutable class
// But note that this only works for
// one-way associations
class X {
Integer x;
immutable;
}
class Y {
immutable;
String s;
0..1 -> 0..1 X;
}
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Another Solution to The Above So the Message No Longer Appears
// Another solution is to not require
// the association to be immutable,
// just the attributes. But this may
// not match the intended semantics.
class X {
immutable Integer x;
}
class Y {
immutable String s;
0..1 -- 0..1 X;
}
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