Make SyntaxToken extend ExpressibleByStringLiteral

[kimdv]

@ahoppen I have open a PR, so we can discuss it here.

From #291

4a. TokenSyntax should be ExpressibleByStringLiteral. That way we wouldn’t need SyntaxFactory.makeIdentifier("myFirstVar"). It might also remove the need for convenience of passing in a String for a TokenSyntax in the convinience initializers because TokenSyntax can now just be expressed by a string literal.

I'm not sure how implement this.

Because if we add ExpressibleByStringLiteral to SyntaxToken, how can it now to create a identifier token, just like when we use SyntaxFactory.makeIdentifier("myOtherVar")

[ahoppen]

Argh, I temporarily forgot that TokenSyntax nodes carry a kind. My initial idea was that let myToken: TokenSyntax = "hello" should create an identifier with the text hello. But since TokenSyntax carries a type, we need to decide whether myToken should indeed be an identifier or maybe some other token like a contextual keyword. So I take back my idea.

I also just realized that since #293 we can write

IdentifierPattern(identifier: .identifier("myOtherVar")),

instead of

IdentifierPattern(identifier: SyntaxFactory.makeIdentifier("myOtherVar")),

which I think is a very precise and short syntax for what we are trying to achieve.

[kimdv]

Good. I was a bit confused. Maybe I didn't know something.

But will close then.