Active updating (original) (raw)
主动修改是计算机编程中，在一项的值变化时，其依赖项的值随之变化的行为模式。与惰性求值（Lazy Evaluation，又译为惰性计算、懒惰求值）相对。 假设数据项A的值依赖于数据项B的值。即B的值发生变化将导致A的值的变化。主动修改是在B变化后立即修改A。被动修改或称惰性求值是在取A的值时才修改A。一个具体例子是对于GUI应用程序，子菜单项的内容列表依赖于程序的状态，可以在程序状态改变时立即修改子菜单的列表（主动修改），也可以在仅当菜单被调用时才修改（被动修改）。 另一个例子是：可以在底层数据改变时立即修改视觉显示，也可以仅在点击"redraw"按钮后修改。 事务处理中的直接修改与延迟修改也是这种例子。
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| dbo:abstract | In computer programming, suppose we have a data item A whose value depends on data item B, i.e., the value of A must be changed after the value of B changes and before the value of A becomes necessary. Active updating is updating A immediately after B changes, while passive updating or lazy updating (lazy evaluation) is updating A immediately before its value is fetched. And example of this distinction is, e.g., in the implementation of GUI applications: the list of submenu items may depend on the state of the application; this list may be updated either as soon as the state of the application changes ("active") or only when the menu is invoked ("passive"). Another example is update a visual display as soon as the underlying data change as opposed to clicking the "redraw" button. In this situation active update may create a problem to deal with: an abrupt change of some part of the display may coincide in time with the saccadic movement of the eye, and the change may go unnoticed by a human observer. (en) 主动修改是计算机编程中，在一项的值变化时，其依赖项的值随之变化的行为模式。与惰性求值（Lazy Evaluation，又译为惰性计算、懒惰求值）相对。 假设数据项A的值依赖于数据项B的值。即B的值发生变化将导致A的值的变化。主动修改是在B变化后立即修改A。被动修改或称惰性求值是在取A的值时才修改A。一个具体例子是对于GUI应用程序，子菜单项的内容列表依赖于程序的状态，可以在程序状态改变时立即修改子菜单的列表（主动修改），也可以在仅当菜单被调用时才修改（被动修改）。 另一个例子是：可以在底层数据改变时立即修改视觉显示，也可以仅在点击"redraw"按钮后修改。 事务处理中的直接修改与延迟修改也是这种例子。 (zh) |
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| dbo:wikiPageWikiLink | dbr:Saccadic_movement dbr:GUI dbr:Computer_programming dbc:Programming_idioms dbr:Lazy_evaluation dbr:Transaction_processing dbr:Deferred_updating dbr:Direct_updating |
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| rdfs:comment | 主动修改是计算机编程中，在一项的值变化时，其依赖项的值随之变化的行为模式。与惰性求值（Lazy Evaluation，又译为惰性计算、懒惰求值）相对。 假设数据项A的值依赖于数据项B的值。即B的值发生变化将导致A的值的变化。主动修改是在B变化后立即修改A。被动修改或称惰性求值是在取A的值时才修改A。一个具体例子是对于GUI应用程序，子菜单项的内容列表依赖于程序的状态，可以在程序状态改变时立即修改子菜单的列表（主动修改），也可以在仅当菜单被调用时才修改（被动修改）。 另一个例子是：可以在底层数据改变时立即修改视觉显示，也可以仅在点击"redraw"按钮后修改。 事务处理中的直接修改与延迟修改也是这种例子。 (zh) In computer programming, suppose we have a data item A whose value depends on data item B, i.e., the value of A must be changed after the value of B changes and before the value of A becomes necessary. Active updating is updating A immediately after B changes, while passive updating or lazy updating (lazy evaluation) is updating A immediately before its value is fetched. And example of this distinction is, e.g., in the implementation of GUI applications: the list of submenu items may depend on the state of the application; this list may be updated either as soon as the state of the application changes ("active") or only when the menu is invoked ("passive"). (en) |
| rdfs:label | Active updating (en) 主动修改 (zh) |
| owl:sameAs | yago-res:Active updating wikidata:Active updating dbpedia-zh:Active updating https://global.dbpedia.org/id/2eHqR |
| prov:wasDerivedFrom | wikipedia-en:Active_updating?oldid=848794376&ns=0 |
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