On: Trampolines in JavaScript

[cousin_it]

Hmm. In your perfect world, the code to solve that problem would look like this one-liner:

    strings.map(toTextNode).map(wrapIn("li")).each(appendTo(ul));

I'm not sure that's the most readable way to solve that problem. In my perfect world, the solution would be a template in a separate file:

    <template name="mytemplate"
              args="strings: array[string]"
      <ul>
        <li foreach="string in strings"
            content="string">
        </li>
      </ul>
    </template>

and in the code you'd do this:

    mytemplate.fill(strings);

Generating HTML is one of those tasks that really deserve a DSL ;-)

Also note that my solution doesn't really follow your pattern of composing several operations. The template loops over the array only once instead of three times. Maybe that's because it feels more natural to some people to nest several operations inside one loop, rather than pull out each operation as its own loop. I share that point of view as well, it feels weird to write a chunk of code differently depending on whether it's inside a loop or outside a loop. YMMV.

Of course the functional approach also supports putting all operations inside one loop. You could build up the composite operation by using a lambda (which would look similar to your initial imperative example), or using some function composition operators (which I wouldn't enjoy reading afterward).

[jdmichal → cousin_it]

Understood, and templating is a good solution also. I specifically wrote what I did based on the original question, which I interpreted as "what does functional programming in a UI look like?" And I wanted to show the progression from a loop to inline lambdas to reusable and generic functions.

[jhart3333 → jdmichal]

Thank you for your thoughtful and informative comment. This is what I read HN for.