`Substring.count` is ambiguous inside a `[Substring].filter` block [Swift 5][Xcode 10P107d]
| Originator: | misacek | ||
| Number: | rdar://48722421 | Date Originated: | March 8 2019, 9:51 PM |
| Status: | Resolved: | ||
| Product: | Xcode 10.2 / Swift 5 | Product Version: | |
| Classification: | Reproducible: | Always |
Summary:
I've created a simple Playground code demonstrating the issue.
Having a string, for example:
"abc def ghi jklmno"
When attempting to call a split – filter – join chain, like:
"abc def ghi jklmno"
.split(separator: " ")
.filter({(substr) -> Bool in return substr.count == 3})
.joined(separator: ", ")
Swift 5 fails to compile the code, stating use of `count` as ambiguous.
Weird behaviours:
• When using an intermediate variable after `split` (thus breaking into two parts — let a = "…".split(…); a.filter(…).joined(…)), compilation succeeds with a correct output.
• When invoking the `substr` block variable before calling `substr.count` (even by putting it on a separate line to only be printed in the variable pane in the Playgrounds), the compilation succeeds with a correct output — acts as a work-around.
• When omitting the `.joined` operation, the compilation succeeds, but `.filter` block incorrectly outputs a result of [[Character]] ( [["a","b","c"], ["d"… ) instead of correct [Substring] ( ["abc","def",… ).
Steps to Reproduce:
See the attached Playground code.
Version/Build:
Xcode 10.2 Beta 4 (10P107d)
Comments
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