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71 lines
1.9 KiB
71 lines
1.9 KiB
2 years ago
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# I'm confused with class `get` `set` and `prop`
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We have 2 places in documentation describing it:
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[A]
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[https://imba.io/docs/basic-syntax/classes#computed-properties](https://imba.io/docs/basic-syntax/classes#computed-properties)
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[B]
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[https://imba.io/docs/basic-syntax/operators#keywords-set](https://imba.io/docs/basic-syntax/operators#keywords-set)
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__[A]__ describes:
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`get`
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> The get syntax binds an object property to a function that will be
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> called when that property is looked up
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But there's no bind. If you call `get` the same as property you get into
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infinite loop. If you call it differently - like in examples on website
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which doesn't support the description clame -
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then it works like a regular function and no difference between using
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`get` or `def` other than self documenting syntax.
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__1. What's the differenece between `get` and `def`?__
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`set`
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> Using set you can define a function that will be called when there is
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> an attempt to set that property.
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Sounds clear but then example doesn't show it and then it's not clear
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until you check it. Proper example:
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```coffee
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class Rect
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sides = 0
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width = 0
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height = 0
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set sides size
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width = size
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height = size
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```
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I would expect different behaviour from `set` - method is called on
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value change > process value > returns processed value > applies
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returned value instead. Probably the thing which is proposed in
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undocumented section as `$set` but with not practical syntax.
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__2. I see no consistency between `get` and `set` as set binds on write
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and get doesn't bind on lookup.__
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No `prop` description or usage in any example of Class documentation.
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__[B]__ describes `prop` and use it in examples:
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`prop`
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>A prop allows a tag property to be set from the outside
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But you have the same behaviour without keyword prop.
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__3. What's the difference between following?__
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```coffee
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class A
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prop a = 1
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# and
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class B
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b = 1
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```
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