Differences
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typing [2017/02/14 10:29] christian [Typed Attributes] |
typing [2017/09/27 18:45] (current) christian [Typed Attributes] |
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| - | The symbol is the type name of the PDF object. So far, the type name corresponds to the class name in the Smalltalk implementation hierarchy. | + | This declares that the attribute # |
| + | * a Contents | ||
| + | * an array of Contents objects. | ||
| A type of an object is used when it gets assigned to an attribute. With the type requirement of the attribute, the object is specialized to the attribute type if possible. If this is not possible, a TypeError is raised. | A type of an object is used when it gets assigned to an attribute. With the type requirement of the attribute, the object is specialized to the attribute type if possible. If this is not possible, a TypeError is raised. | ||
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| Rectangle>> | Rectangle>> | ||
| - | < | + | < |
| ^self at: 4 | ^self at: 4 | ||
| </ | </ | ||
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| </ | </ | ||
| When an object is not a subclass of a type, it can be specialized if the objects class subsumes the type. | When an object is not a subclass of a type, it can be specialized if the objects class subsumes the type. | ||
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