hello ,
I find a bug like this:
zhaoliangdeMacBook-Pro:~ zhaoliang$ swift
Welcome to Apple Swift version 2.1.1 (swiftlang-700.1.101.15 clang-700.1.81). Type :help for assistance.
1> var i =3
repl.swift:1:7: error: prefix '=' is reserved
var i =3
^
1> var i=3
i: Int = 3
2>
Hi Zhaoliang,
Try adding a space between the “=“ & “3”
var i = 3
instead of
var i =3
That should fix the issue.
The second way makes it think you are trying to use it as a prefix operator instead of an assignment.
Nerd . Designer . Developer
Jo Albright
On Jan 9, 2016, at 12:07 AM, zhaoliang via swift-dev <swift-dev@swift.org> wrote:
hello ,
I find a bug like this:zhaoliangdeMacBook-Pro:~ zhaoliang$ swift
Welcome to Apple Swift version 2.1.1 (swiftlang-700.1.101.15 clang-700.1.81). Type :help for assistance.
1> var i =3
repl.swift:1:7: error: prefix '=' is reserved
var i =3
^1> var i=3
i: Int = 3
2>_______________________________________________
swift-dev mailing list
swift-dev@swift.org
https://lists.swift.org/mailman/listinfo/swift-dev
That's right. Swift's operators are whitespace-sensitive. The rules are:
* Whitespace on both sides: infix operator
* Whitespace on neither side: infix operator
* Whitespace on only one side: prefix or postfix operator
Therefore the expression `i =3` uses prefix operator = . There is no such operator, and it's reserved so you can't write your own.
`i = 3` and `i=3` and `i = 3` are both the ordinary infix operator = .
Obligatory open-source opportunity: add a compiler fix-it for this. (Perhaps just the prefix/postfix = case specifically, perhaps the more general case where the requested operator does not exist but an operator with different fixity does.)
On Jan 8, 2016, at 10:54 PM, Jo Albright via swift-dev <swift-dev@swift.org> wrote:
Hi Zhaoliang,
Try adding a space between the “=“ & “3”
var i = 3
instead of
var i =3
That should fix the issue.
The second way makes it think you are trying to use it as a prefix operator instead of an assignment.
Nerd . Designer . Developer
Jo AlbrightOn Jan 9, 2016, at 12:07 AM, zhaoliang via swift-dev <swift-dev@swift.org <mailto:swift-dev@swift.org>> wrote:
hello ,
I find a bug like this:zhaoliangdeMacBook-Pro:~ zhaoliang$ swift
Welcome to Apple Swift version 2.1.1 (swiftlang-700.1.101.15 clang-700.1.81). Type :help for assistance.
1> var i =3
repl.swift:1:7: error: prefix '=' is reserved
var i =3
^1> var i=3
i: Int = 3
2>_______________________________________________
swift-dev mailing list
swift-dev@swift.org <mailto:swift-dev@swift.org>
https://lists.swift.org/mailman/listinfo/swift-dev_______________________________________________
swift-dev mailing list
swift-dev@swift.org
https://lists.swift.org/mailman/listinfo/swift-dev
Swift 2.2 produces a better error message for this:
error: '=' must have consistent whitespace on both sides
var i =3
^
-Chris
On Jan 9, 2016, at 2:21 AM, Greg Parker via swift-dev <swift-dev@swift.org> wrote:
That's right. Swift's operators are whitespace-sensitive. The rules are:
* Whitespace on both sides: infix operator
* Whitespace on neither side: infix operator
* Whitespace on only one side: prefix or postfix operatorTherefore the expression `i =3` uses prefix operator = . There is no such operator, and it's reserved so you can't write your own.
`i = 3` and `i=3` and `i = 3` are both the ordinary infix operator = .Obligatory open-source opportunity: add a compiler fix-it for this. (Perhaps just the prefix/postfix = case specifically, perhaps the more general case where the requested operator does not exist but an operator with different fixity does.)