JSFiddle - React, Tailwind, and code Playground

HTML

How many <a href="http://www.example.com/42">roads</a> does a man walk down? 42. The quick brown fox jumps -4.2 m over the lazy 3dog4.

CSS

.foo { background-color: red; }

JavaScript

function autospan() {
    var exp = /-?[\d.]+/g;

    $('*:not(script, style, textarea)').contents().each(function() {
        if (this.nodeType == Node.TEXT_NODE) {
            var textNode = $(this);
            var span = $('<span/>').text(this.nodeValue);
            span.html(span.html().replace(exp, '<span class="foo">$&</span>'));
            textNode.replaceWith(span);
        }
    });
}

$(autospan);