Unneeded Parentheses in Closure Argument

Parentheses are not needed when declaring closure arguments.

• Identifier: unneeded_parentheses_in_closure_argument
• Enabled by default: Disabled
• Supports autocorrection: Yes
• Kind: style
• Analyzer rule: No
• Minimum Swift compiler version: 3.0.0
• Default configuration: warning

Non Triggering Examples

let foo = { (bar: Int) in }

let foo = { bar, _  in }

let foo = { bar in }

let foo = { bar -> Bool in return true }

Triggering Examples

call(arg: { ↓(bar) in })

call(arg: { ↓(bar, _) in })

let foo = { ↓(bar) -> Bool in return true }

foo.map { ($0, $0) }.forEach { ↓(x, y) in }

foo.bar { [weak self] ↓(x, y) in }

[].first { ↓(temp) in
    [].first { ↓(temp) in
        [].first { ↓(temp) in
            _ = temp
            return false
        }
        return false
    }
    return false
}

[].first { temp in
    [].first { ↓(temp) in
        [].first { ↓(temp) in
            _ = temp
            return false
        }
        return false
    }
    return false
}