The grammar is missing trailing commas [SE-0439]

[jansorg]

Location

https://docs.swift.org/swift-book/documentation/the-swift-programming-language/summaryofthegrammar

Description

As far as I can tell, the changes for https://github.com/swiftlang/swift-evolution/blob/main/proposals/0439-trailing-comma-lists.md are not yet contained in the official grammar.

At least the trailing comma of a function-call-expression is not contained in the grammar:

func first(first: String, second: String) -> String {
    return first
}

func something() -> String {
    return first(
        first: "a",
        second: "b"
    )
}

Correction

If I'm not mistaken, the rule for function-call-argument-list should allow a trailing comma.

rdar://144570685

[amartini51]

Working on a branch https://github.com/amartini51/swift-book/tree/trailing_comma_144570685