[basex-talk] Lookup operator, conformance

Hello,

I noticed that the lookup operator (?) accepts as key expression also non-parenthesized expressions, e.g.:

$map?$key

It seems to me that the XQuery spec does not allow that - the key specifier must be an NCName, an integer, * or a parenthesized expression [1]: [126] KeySpecifier ::= NCName | IntegerLiteral | ParenthesizedExpr | "*" So only this should be allowed: $map?($key)

But I am not quite sure if I do not overlook something.

*My question*: is the acceptance of non-parenthesized key expressions conformant behaviour, or a (certainly intended) laxness?

Kind regards, Hans-Jürgen

[1] https://www.w3.org/TR/xquery-31/#id-lookup