Simplify argument-list syntax.

[nigelmegitt]

Looks like a typo in the syntax for argument-list: the one of the terms is argument-list rather than <expression>.

Currently:

argument-list
  : <expression>
  | argument-list <lwsp>? "," <lwsp>? <expression>

Should probably be:

argument-list
  : <expression>
  | <expression> <lwsp>? "," <lwsp>? <expression>

[nigelmegitt]

By the way, if the recursion here was intended, so that the list could be unbounded, then it should be:

argument-list
  : <expression>
  | <expression> (<lwsp>? "," <lwsp>? <expression>)+

or even more simply:

argument-list
  : <expression> (<lwsp>? "," <lwsp>? <expression>)*

[nigelmegitt]

I noticed also that this problem is duplicated many times over in <expression> where for example logical-or-expression is defined recursively in terms of itself.

[skynavga]

@nigelmegitt the recursion is intended; however, I will address your comments in the PR

[skynavga]

The PR (#610) does not "simplify" any of the additional @condition expressions, since that would make the syntax more complex and since the current syntax is consistent with the formal syntax of other expression languages, e.g., see ECMA-262 - Grammar Summary - Expressions, upon which I based the current syntax.

[nigelmegitt]

OK, good to know the recursion is intended. I found it slightly mind-bending working through all the condition expressions and persuading myself that in the end they worked, but now my mind is bent, no need to try straightening it out again. In other words, I'm okay with that.