Re: Swift generics, circular type declarations, and segfaults, oh my!
Re: Swift generics, circular type declarations, and segfaults, oh my!
- Subject: Re: Swift generics, circular type declarations, and segfaults, oh my!
- From: has <email@hidden>
- Date: Sun, 06 Sep 2015 18:25:34 +0100
On 05/09/2015 07:07, Charles Srstka wrote:
On Sep 4, 2015, at 7:59 PM, Quincey Morris
<email@hidden
<mailto:email@hidden>> wrote:
On Sep 4, 2015, at 16:31 , has <email@hidden
<mailto:email@hidden>> wrote:
At risk of derail...
Do you mean “derail” or “detail”? I feel like I’m drowning in details.
Yeah, this is why I kept the original posts light on specifics.
Obviously adding these details didn't help clarify at all - but see
Charles' final paragraph below.
What I mean is, in:
TextEdit().documents[1].text.words.get()
the instances represented by ‘TextEdit()’, 'TextEdit().documents[1]’,
'TextEdit().documents[1].text’ are just setting the context for what
the instance represented by 'TextEdit().documents[1].text.words’ is
being asked to retrieve.
Basically. Each of those intermediates describes a valid query in
itself; you just keep chaining var/method calls until you build up the
query you actually want. Internally, it's just adding to a linked list
of AE records (in pseudocode):
[every word [text [document 1 [application "TextEdit"]]]]
The final 'get' command packs that query into a 'getdata' Apple event
and sends it off to the app to evaluate. Kinda like sending XPath
queries over XML-RPC.
The way I’m reading it, he or she is wrapping an application’s
scripting dictionary, creating a Swift object to wrap each construct
that would represent a noun, so to speak, in AppleScript. However,
these entities are expensive to obtain, involving IPC, so s/he’s
loading them lazily.
Nope (he). Apple event IPC isn't a proxy object-based system like DO;
it's not OOP at all. (Dictionaries are a lie.) The AE bridge only models
queries, not 'classes'. So I only need to define a few classes, one to
represent each type of query: root node, one-to-one relationship,
one-to-many relationship, insertion point.
What this means is that the objects are all going to have some number
of properties that, when the user accesses them, will necessitate
creating a new wrapper object.
Yes. And because some properties (vars) represent one-to-one
relationships, others represent one-to-many, they need to instantiate
different query classes: ObjectSpecifier/ElementsSpecifier. Which is why
I can't just use Self - e.g. the ObjectSpecifier representing the 'text'
property needs to return an ElementsSpecifier to represent the 'words'
elements.
I’m not the most knowledgeable about AppleScript, but what it sounds
like from s/he’s saying is that the relationships between the
AppleScript objects fall into three main categories, and for each type
of object, there will be only one specific class to which each of the
three relationships can point, so the object should be representable
by a Swift generic with three parameterized types. However, if an
object points to more of the same type of object, this results in
something like Foo<Foo>, and this causes either the compiler or the
runtime to crash since it’s apparently not built to handle a generic
being passed an object of its own type (honestly, this sounds like
something warranting a Radar). S/he is asking if anyone knows of any
way around this.
Yes! Exactly this. And yeah, I'm getting that sinking Radar feeling too.
But since I'm relatively new to Swift, I'm just holding out a vain hope
that there's some sort of solution that's embarrassingly obvious to
everyone else but me.
Thanks,
has
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| References: | |
| | >Swift generics, circular type declarations, and segfaults, oh my! (From: has <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: Fritz Anderson <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: has <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: Quincey Morris <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: has <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: Quincey Morris <email@hidden>) |
| | >Re: Swift generics, circular type declarations, and segfaults, oh my! (From: Charles Srstka <email@hidden>) |