Vue: [feature request]: v-else for v-show

[gbezyuk]

I know it's just a piece of syntax sugar, but why not to support v-else for v-show directive?

[LinusBorg]

I like the idea, but also have som reservations considering explicitness of the behaviour:

1. Two different results from the same directive:
   
   
   
   • when used with v-if, v-else would insert/remove the element
   
   
   • when used with v-show, v-else would show/hide the element.
   
   
2. since v-if and v-show operate fundamentally different, we would in essence need two implementations of v-else that mirror this behaviour.
3. in conjunction with your other proposal, #4174, there would now be 3 different directives that I have to look for in order to understand what v-else does in a particular situation. (_"Oh there's v-show, so that determines weither v-else - oh, no - it's the v-for actually!"_)

[gbezyuk]

(1) and (2) are obviously true.
(3) doesn't seem to be the real issue, as v-else is always a continuation of the previously defined element/directive.

Anyway, we could use a different name in case we'll come up with a better one.

[posva]

This was removed in Vue 2: https://github.com/vuejs/vue/issues/2873
I couldn't find the thread where this was discussed but the cost of maintaining v-else with the extra logic was not enough for a simple syntactic sugar for v-show="condition"/v-else vs v-show="condition"/v-show="!condition". Maybe @blake-newman recall a bit better the other reasons