var distanceCache: [Int: Int] = Dictionary<Int, Int>()
It is very long and tedious to write especially if what I am storing
changes.
I propose we be allowed to do the following:
*var distanceCache: [Int: Int] = *
If this isn't possible then I wouldn't mind having some way of telling the
compiler to auto create it like so:
*var distanceCache: [Int: Int] ()*
or
*var distanceCache: [Int: Int] = new Dictionary*
or even:
*var distanceCache: [Int: Int] = auto*
*auto var distanceCache: [Int: Int]*
(auto short for auto create)
Perhaps this dictionary syntax is just confusing and it was a bad idea to
make it the same as an array. Most languages use "{" so why did swift
choose to share "[" with arrays and dictionaries.
Perhaps instead of "auto" we could allow "lazy" to create a default lazy
constructor for these cases ?
···
On Tue, Jan 5, 2016 at 12:39 PM, James Campbell <james@supmenow.com> wrote:
See this code:
var distanceCache: [Int: Int] = Dictionary<Int, Int>()
It is very long and tedious to write especially if what I am storing
changes.
I propose we be allowed to do the following:
*var distanceCache: [Int: Int] = *
If this isn't possible then I wouldn't mind having some way of telling the
compiler to auto create it like so:
*var distanceCache: [Int: Int] ()*
or
*var distanceCache: [Int: Int] = new Dictionary*
or even:
*var distanceCache: [Int: Int] = auto*
*auto var distanceCache: [Int: Int]*
(auto short for auto create)
Perhaps this dictionary syntax is just confusing and it was a bad idea to
make it the same as an array. Most languages use "{" so why did swift
choose to share "[" with arrays and dictionaries.
--
Wizard
james@supmenow.com
+44 7523 279 698
See this code:
var distanceCache: [Int: Int] = Dictionary<Int, Int>()
It is very long and tedious to write especially if what I am storing changes.
I propose we be allowed to do the following:
var distanceCache: [Int: Int] =
You can do
var distanceCache: [Int: Int] = [:]
Also
var distanceCache2 = [Int: Int]()
Perhaps this dictionary syntax is just confusing and it was a bad idea to make it the same as an array. Most languages use "{" so why did swift choose to share "[" with arrays and dictionaries.
It’s not the same, you need the colons inside. I imagine that braces were discarded on the grounds that it would confuse the compiler with respect to closures, for example
var myClosure = {} // is a variable of type () -> ()
···
On 5 Jan 2016, at 12:39, James Campbell via swift-evolution <swift-evolution@swift.org> wrote:
The problem for me is that is so counter intuitive I didn't even know you
could do that.
···
On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira < jeremy.j.pereira@googlemail.com> wrote:
I don’t understand what the problem is
> On 5 Jan 2016, at 12:39, James Campbell via swift-evolution < > swift-evolution@swift.org> wrote:
>
> See this code:
> var distanceCache: [Int: Int] = Dictionary<Int, Int>()
>
> It is very long and tedious to write especially if what I am storing
changes.
>
> I propose we be allowed to do the following:
> var distanceCache: [Int: Int] =
You can do
var distanceCache: [Int: Int] = [:]
Also
var distanceCache2 = [Int: Int]()
> Perhaps this dictionary syntax is just confusing and it was a bad idea
to make it the same as an array. Most languages use "{" so why did swift
choose to share "[" with arrays and dictionaries.
It’s not the same, you need the colons inside. I imagine that braces were
discarded on the grounds that it would confuse the compiler with respect to
closures, for example
var myClosure = {} // is a variable of type () -> ()
You’re completely right, but we don’t need to change the swift language to fix that. As of 3f19714, which I just pushed, we now emit this error message (which includes a fixit hint to insert the colon):
t.swift:2:33: error: use [:] to get an empty dictionary literal
var distanceCache: [Int: Int] =
^
:
instead of:
t.swift:2:33: error: contextual type '[Int : Int]' cannot be used with array literal
var distanceCache: [Int: Int] =
^~
That should address the problem, thanks for pointing this out!
-Chris
···
On Jan 5, 2016, at 4:51 AM, James Campbell via swift-evolution <swift-evolution@swift.org> wrote:
The problem for me is that is so counter intuitive I didn't even know you could do that.
On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com <mailto:jeremy.j.pereira@googlemail.com>> wrote:
I don’t understand what the problem is
> On 5 Jan 2016, at 12:39, James Campbell via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
>
> See this code:
> var distanceCache: [Int: Int] = Dictionary<Int, Int>()
>
> It is very long and tedious to write especially if what I am storing changes.
>
> I propose we be allowed to do the following:
> var distanceCache: [Int: Int] =
You can do
var distanceCache: [Int: Int] = [:]
Also
var distanceCache2 = [Int: Int]()
> Perhaps this dictionary syntax is just confusing and it was a bad idea to make it the same as an array. Most languages use "{" so why did swift choose to share "[" with arrays and dictionaries.
It’s not the same, you need the colons inside. I imagine that braces were discarded on the grounds that it would confuse the compiler with respect to closures, for example
var myClosure = {} // is a variable of type () -> ()
The problem for me is that is so counter intuitive I didn't even know you could do that.
The first one is a bit counter intuitive and I agree that
var distanceCache: [Int: Int] =
might be an improvement, albeit not one I think many people would agree is worth doing. However, the second one is a natural extrapolation from the equivalent array syntax i.e.
var array = [Int]()
var dictionary = [String: Int]()
···
On 5 Jan 2016, at 12:51, James Campbell <james@supmenow.com> wrote:
On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com> wrote:
I don’t understand what the problem is
> On 5 Jan 2016, at 12:39, James Campbell via swift-evolution <swift-evolution@swift.org> wrote:
>
> See this code:
> var distanceCache: [Int: Int] = Dictionary<Int, Int>()
>
> It is very long and tedious to write especially if what I am storing changes.
>
> I propose we be allowed to do the following:
> var distanceCache: [Int: Int] =
You can do
var distanceCache: [Int: Int] = [:]
Also
var distanceCache2 = [Int: Int]()
> Perhaps this dictionary syntax is just confusing and it was a bad idea to make it the same as an array. Most languages use "{" so why did swift choose to share "[" with arrays and dictionaries.
It’s not the same, you need the colons inside. I imagine that braces were discarded on the grounds that it would confuse the compiler with respect to closures, for example
var myClosure = {} // is a variable of type () -> ()
On Tue, Jan 5, 2016 at 6:58 PM, Chris Lattner <clattner@apple.com> wrote:
You’re completely right, but we don’t need to change the swift language to
fix that. As of 3f19714, which I just pushed, we now emit this error
message (which includes a fixit hint to insert the colon):
t.swift:2:33: error: use [:] to get an empty dictionary literal
var distanceCache: [Int: Int] =
^
:
instead of:
t.swift:2:33: error: contextual type '[Int : Int]' cannot be used with
array literal
var distanceCache: [Int: Int] =
^~
That should address the problem, thanks for pointing this out!
-Chris
On Jan 5, 2016, at 4:51 AM, James Campbell via swift-evolution < > swift-evolution@swift.org> wrote:
The problem for me is that is so counter intuitive I didn't even know you
could do that.
On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira < > jeremy.j.pereira@googlemail.com> wrote:
I don’t understand what the problem is
> On 5 Jan 2016, at 12:39, James Campbell via swift-evolution < >> swift-evolution@swift.org> wrote:
>
> See this code:
> var distanceCache: [Int: Int] = Dictionary<Int, Int>()
>
> It is very long and tedious to write especially if what I am storing
changes.
>
> I propose we be allowed to do the following:
> var distanceCache: [Int: Int] =
You can do
var distanceCache: [Int: Int] = [:]
Also
var distanceCache2 = [Int: Int]()
> Perhaps this dictionary syntax is just confusing and it was a bad idea
to make it the same as an array. Most languages use "{" so why did swift
choose to share "[" with arrays and dictionaries.
It’s not the same, you need the colons inside. I imagine that braces were
discarded on the grounds that it would confuse the compiler with respect to
closures, for example
var myClosure = {} // is a variable of type () -> ()
On Tue, Jan 5, 2016 at 1:01 PM, Jeremy Pereira < jeremy.j.pereira@googlemail.com> wrote:
> On 5 Jan 2016, at 12:51, James Campbell <james@supmenow.com> wrote:
>
> The problem for me is that is so counter intuitive I didn't even know
you could do that.
The first one is a bit counter intuitive and I agree that
var distanceCache: [Int: Int] =
might be an improvement, albeit not one I think many people would agree is
worth doing. However, the second one is a natural extrapolation from the
equivalent array syntax i.e.
var array = [Int]()
var dictionary = [String: Int]()
>
> On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira < > jeremy.j.pereira@googlemail.com> wrote:
> I don’t understand what the problem is
>
> > On 5 Jan 2016, at 12:39, James Campbell via swift-evolution < > swift-evolution@swift.org> wrote:
> >
> > See this code:
> > var distanceCache: [Int: Int] = Dictionary<Int, Int>()
> >
> > It is very long and tedious to write especially if what I am storing
changes.
> >
> > I propose we be allowed to do the following:
> > var distanceCache: [Int: Int] =
>
> You can do
>
> var distanceCache: [Int: Int] = [:]
>
> Also
>
> var distanceCache2 = [Int: Int]()
>
>
> > Perhaps this dictionary syntax is just confusing and it was a bad idea
to make it the same as an array. Most languages use "{" so why did swift
choose to share "[" with arrays and dictionaries.
>
> It’s not the same, you need the colons inside. I imagine that braces
were discarded on the grounds that it would confuse the compiler with
respect to closures, for example
>
> var myClosure = {} // is a variable of type () -> ()
>
>
> >
> > --
> > Wizard
> > james@supmenow.com
> > +44 7523 279 698
> > _______________________________________________
> > swift-evolution mailing list
> > swift-evolution@swift.org
> > https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
>
>
> --
> Wizard
> james@supmenow.com
> +44 7523 279 698
Yes. In general, you can write [T] anywhere you can write Array<T> and [U : V] anywhere you can write Dictionary<U, V>. The are both syntactic sugar.
···
On 5 Jan 2016, at 13:42, James Campbell <james@supmenow.com> wrote:
On Tue, Jan 5, 2016 at 1:01 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com> wrote:
> On 5 Jan 2016, at 12:51, James Campbell <james@supmenow.com> wrote:
>
> The problem for me is that is so counter intuitive I didn't even know you could do that.
The first one is a bit counter intuitive and I agree that
var distanceCache: [Int: Int] =
might be an improvement, albeit not one I think many people would agree is worth doing. However, the second one is a natural extrapolation from the equivalent array syntax i.e.
var array = [Int]()
var dictionary = [String: Int]()
>
> On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com> wrote:
> I don’t understand what the problem is
>
> > On 5 Jan 2016, at 12:39, James Campbell via swift-evolution <swift-evolution@swift.org> wrote:
> >
> > See this code:
> > var distanceCache: [Int: Int] = Dictionary<Int, Int>()
> >
> > It is very long and tedious to write especially if what I am storing changes.
> >
> > I propose we be allowed to do the following:
> > var distanceCache: [Int: Int] =
>
> You can do
>
> var distanceCache: [Int: Int] = [:]
>
> Also
>
> var distanceCache2 = [Int: Int]()
>
>
> > Perhaps this dictionary syntax is just confusing and it was a bad idea to make it the same as an array. Most languages use "{" so why did swift choose to share "[" with arrays and dictionaries.
>
> It’s not the same, you need the colons inside. I imagine that braces were discarded on the grounds that it would confuse the compiler with respect to closures, for example
>
> var myClosure = {} // is a variable of type () -> ()
>
>
> >
> > --
> > Wizard
> > james@supmenow.com
> > +44 7523 279 698
> > _______________________________________________
> > swift-evolution mailing list
> > swift-evolution@swift.org
> > https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
>
>
> --
> Wizard
> james@supmenow.com
> +44 7523 279 698
Yes. All of these variants are covered in the book The Swift Programming Language in some detail.
Alex
–––––
Alexander Kempgen
alex@kempgen.de
···
Am 05.01.2016 um 14:42 schrieb James Campbell via swift-evolution <swift-evolution@swift.org>:
So the [Int]() is shorthand for Array<Int>()
On Tue, Jan 5, 2016 at 1:01 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com <mailto:jeremy.j.pereira@googlemail.com>> wrote:
> On 5 Jan 2016, at 12:51, James Campbell <james@supmenow.com <mailto:james@supmenow.com>> wrote:
>
> The problem for me is that is so counter intuitive I didn't even know you could do that.
The first one is a bit counter intuitive and I agree that
var distanceCache: [Int: Int] =
might be an improvement, albeit not one I think many people would agree is worth doing. However, the second one is a natural extrapolation from the equivalent array syntax i.e.
var array = [Int]()
var dictionary = [String: Int]()
>
> On Tue, Jan 5, 2016 at 12:50 PM, Jeremy Pereira <jeremy.j.pereira@googlemail.com <mailto:jeremy.j.pereira@googlemail.com>> wrote:
> I don’t understand what the problem is
>
> > On 5 Jan 2016, at 12:39, James Campbell via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
> >
> > See this code:
> > var distanceCache: [Int: Int] = Dictionary<Int, Int>()
> >
> > It is very long and tedious to write especially if what I am storing changes.
> >
> > I propose we be allowed to do the following:
> > var distanceCache: [Int: Int] =
>
> You can do
>
> var distanceCache: [Int: Int] = [:]
>
> Also
>
> var distanceCache2 = [Int: Int]()
>
>
> > Perhaps this dictionary syntax is just confusing and it was a bad idea to make it the same as an array. Most languages use "{" so why did swift choose to share "[" with arrays and dictionaries.
>
> It’s not the same, you need the colons inside. I imagine that braces were discarded on the grounds that it would confuse the compiler with respect to closures, for example
>
> var myClosure = {} // is a variable of type () -> ()
>
>
> >
> > --
> > Wizard
> > james@supmenow.com <mailto:james@supmenow.com>
> > +44 7523 279 698 <tel:%2B44%207523%20279%20698>
> > _______________________________________________
> > swift-evolution mailing list
> > swift-evolution@swift.org <mailto:swift-evolution@swift.org>
> > https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
>
>
> --
> Wizard
> james@supmenow.com <mailto:james@supmenow.com>
> +44 7523 279 698 <tel:%2B44%207523%20279%20698>