at:tutorial:reflection
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at:tutorial:reflection [2007/07/13 09:37] – jorge | at:tutorial:reflection [2007/07/18 16:32] – jorge | ||
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====== Reflective Programming ====== | ====== Reflective Programming ====== | ||
- | Reflection is an integral part of the AmbientTalk programming language. Through the use of reflection, the core language can be extended with both programming support as well as new language constructs. Both examples require a different kind of reflective access. The introduction of programming support (e.g. to visualise AmbientTalk objects) relies on **introspection**, | + | [[wp> |
- | The reflective model of AmbientTalk is based on **mirrors**, meta-level objects which allow one to reflect on an objects state and behaviour. How to create such mirrors and how they can be used is demonstrated in the first part of the tutorial. The second part of the tutorial showcases how to construct mirages, objects which override the default meta-level operations with custom behaviour. This tutorial concludes with a brief overview of the meta-level operations which are offered by AmbientTalk mirrors. | + | The reflective model of AmbientTalk is based on [[http:// |
===== Mirrors ===== | ===== Mirrors ===== | ||
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def baseObject := object: { | def baseObject := object: { | ||
def field := nil; | def field := nil; | ||
- | def canonicalMethod() { nil } | + | def canonicalMethod() { nil }; |
- | def keyworded: arg1 method: arg2 { nil } | + | def keyworded: arg1 method: arg2 { nil }; |
}; | }; | ||
def mirror := reflect: baseObject; | def mirror := reflect: baseObject; | ||
def slots := mirror.listSlots(); | def slots := mirror.listSlots(); | ||
- | slots.each: { | slot | system.println() }; | + | slots.each: { | slot | system.println(slot) }; |
</ | </ | ||
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===== Mirages ===== | ===== Mirages ===== | ||
- | Extending the AmbientTalk core language involves adding objects which have a different implementation for some of the default meta-operations. In this part of the tutorial we describe how a programmer could define objects which allow for the dynamic addition of unknown methods and fields. First of all, we need to create a mirror instance which we can use to create new objects from. This can be performed using the '' | + | Extending the AmbientTalk core language involves adding objects which have a different implementation for some of the default meta-operations. In this part of the tutorial, we describe how a programmer could define objects which allow for the dynamic addition of unknown methods and fields. First of all, we need to create a mirror instance which we can use to create new objects from. This can be performed using the '' |
< | < | ||
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} else: { | } else: { | ||
super^doesNotUnderstand(selector); | super^doesNotUnderstand(selector); | ||
- | } | + | }; |
- | } | + | }; |
} | } | ||
</ | </ | ||
- | This mirror overrides the default implementation of the meta-operation '' | + | This mirror overrides the default implementation of the meta-operation '' |
< | < |
at/tutorial/reflection.txt · Last modified: 2010/11/16 16:32 by tvcutsem