additional argument to print

[neolao]

Add a format function to customize cell output for objects.

[xpl]

@neolao Thanks for the PR! It is indeed a very useful feature.

But there may be a bit of confusion with the existing print function... What do you think — is it possible to avoid introducing the new format function, but just extend the semantics of the existing print? It would require lifting the application of print from asColumns:

        cells           = rows.map (r => r.map (c => (c === undefined) ? '' : cfg_.print (c).replace (/\n/g, '\\n'))),

...to asTable (the "front end" of asColumns) — to somewhere here:

/*  Print arrays  */

    if (arr[0] && Array.isArray (arr[0]))
        return asColumns (arr, cfg).join ('\n') // <---- here?

Just as you apply the newly introduced format below that block, here:

/*  Print objects   */

    const colNames        = [...new Set ([].concat (...arr.map (O.keys)))],
          columns         = [colNames.map (cfg.title), ...arr.map (o => colNames.map (key => o[key]))],

So that asColumns would receive the array that is already formatted with the print. For objects the second argument of print would be the key (so basically what the format does), and for arrays it would be the column index.

What do you think?

[neolao]

Oh yes, good point. I will make a change

[neolao]

Done with 2 use cases for the tests

[xpl]

@neolao That is really awesome, thanks. I'll merge it now.

[xpl]

I've added a mention to the docs, also.