Ordered set insert requires duplicate checks

[TomokiMiyauci]

What is the issue with the Infra Standard?

In the current specification, "add" is not defined.

infra/infra.bs

Lines 1492 to 1493 in 0805cea

	<p>To <dfn export for=list,set>insert</dfn> an <a for=list>item</a> into a <a>list</a> before an
	index is to add the given item to the list between the given index &minus; 1 and the given index. If

Therefore, insert in ordered set is missing the “do nothing in case of duplicate item” statement.

There should be a definition for ordered set like append or prepend.

[domenic]

Can you give an example of a spec that needs insert, and for which append/prepend does not suffice?

[TomokiMiyauci]

My understanding is that insert is already defined for set as well as list.

<dfn export for=list,set>insert</dfn>

Is this incorrect?

[domenic]

Yes, I'm just wondering if we should delete that and rely on people using append/prepend instead.

[TomokiMiyauci]

It seems necessary to investigate how much the ordered set insert is being referenced.