lambdas with void return cause compiler crash about nim

[metagn]

Reduced:

let x = proc (): auto = void

Or even:

let x = proc (): typedesc = void

More obscure case but gives the same error:

proc foo(): typedesc = void
foo()

() => discard ... doesn't work ... () => (discard) ... works but how does that look to a newcomer

Well => is an operator and discard is a statement, they cannot form an infix expression together.

(discard) is special cased in the parser along with things like (let ...), (var ...) to be equivalent to (; discard), i.e. a statement list expression ((a; b; c)) containing a single statement. The part in the manual covering statement list expressions does not acknowledge this though, it is only covered in the grammar.