Clarify syntax of strings in match and search regexp arguments

[glyn]

Currently the spec doesn't make it completely clear whether regexp strings need to be enclosed in double quotes or whether single quotes are also acceptable.

My reading of the normative parts of the current spec is that the arguments need to be enclosed in double quotes because they must be of type Value. If this is the intention, we should provide an example showing single quotes are not allowed. Currently, there is an example showing that single quotes are allowed.

[gregsdennis]

This seems related to #362. That issue concluded that strings in expressions, including those passed into functions, can be single- or double-quoted, just like in name selectors.

My reading of the normative parts of the current spec is that the arguments need to be enclosed in double quotes because they must be of type Value.

Where are you seeing this?

The ABNF says

function-argument       = filter-path / comparable

and comparable just includes string-literal which uses either single- or double-quotes.

I expect that regex strings should match requirements of any other string.

[glyn]

Thanks @gregsdennis. On reflection, I think the spec is clear as is.