我对AppleScript引用感到困惑…我几乎从未在AppleScript中开发过,并且很难找到关于AppleScript如何处理引用的好文档。以下代码失败,因为AppleScript
Canât make firstValue of hash into type reference.
:
on run
foo()
end run
on foo()
set the hash to {firstValue:1, secondValue:2}
set the hashRef to a reference to the hash
return the firstValue of hashRef
end foo
但是下面的代码可以工作——相同的代码,但是我在
run
处理程序而不是
foo
汉德勒:
on run
set the hash to {firstValue:1, secondValue:2}
set the hashRef to a reference to the hash
return the firstValue of hashRef
end run
为什么第一个代码示例在第二个代码示例工作时失败?更好的问题是,有人能指点我向文档的方向解释这一点吗?这样我就能知道我的错误是什么?
编辑:
菲利普的回答为我指明了正确的方向,我现在明白了是什么让我困惑了。
The official AppleScript docs
声明“applescript通过引用传递所有参数,这意味着传递的变量在处理程序和调用程序之间共享,就像处理程序使用set命令创建了一个变量一样”。
然而
,这并不意味着AppleScript正在传递
AppleScript引用对象
作为每个参数!
下面是更详细的代码示例,以显示我开发的最终工作解决方案:
on run
foo()
end run
on isRef(someValue)
try
someValue as reference
return true
on error
return false
end try
end isRef
on foo()
log "In foo()"
set the objectList to makeObjectList()
log "objectList isRef =" & isRef(objectList)
set theObject to makeObject given id:0, name:"Test"
addObjectToObjectList(theObject, objectList)
log "foo(): object name =" & name of theObject
log item 1 of allItems of objectList
log item 1 of goodItems of objectList
set the name of item 1 of allItems of objectList to "Test3"
log item 1 of allItems of objectList
log item 1 of goodItems of objectList
end foo
on makeObjectList()
set the hash to {allItems:{}, goodItems:{}, badItems:{}}
return the hash
end makeObjectList
on makeObject given name:theName, id:theId
set theObject to {name:theName, id:theId}
return theObject
end makeObject
on addObjectToObjectList(object, objectList)
log "In addObjectToObjectList"
log "object isRef =" & isRef(object)
copy object to the end of allItems of the objectList
set objectRef to a reference to the last item in allItems of the objectList
set name of objectRef to "Test2"
log "object name =" & name of object
log "objectRef isRef =" & isRef(objectRef)
log "objectRef name =" & name of (contents of objectRef)
copy objectRef to the end of goodItems of the objectList
end addObjectToObjectList
其输出如下:
(*In foo()*)
(*objectList isRef =false*)
(*In addObjectToObjectList*)
(*object isRef =false*)
(*object name =Test*)
(*objectRef isRef =true*)
(*objectRef name =Test2*)
(*foo(): object name =Test*)
(*name:Test2, id:0*)
(*name:Test2, id:0*)
(*name:Test3, id:0*)
(*name:Test3, id:0*)
关键是,我不能在处理程序中引用局部变量——但是只要这些引用被存储回记录中,我就可以引用记录的某些部分,这就是我所追求的功能。
我怀疑有人会把这个问题读得这么深
:-)
