Underscore templates with Mustache style tags and include functionality

underscore_templating.js

var templates = {
    register: function (key, template) {
        this[key] = _.template(
            '<% ' + 
            'var include=_.bind(function(k,d){print(this[k](d))},this);' + 
            'var includeEach=_.bind(function(k,d){_.each(d,function(v){print(this[k](v))},this)},this);' + 
            'var includeIf=_.bind(function(k,d){if(d)print(this[k](d))},this);' + 
            ' %>' + 
            template, 
            null, 
            {variable: 'data'}
        );
        return this;
    }
};

templates.register(
    'person',
    '<p><%= data.name %></p><% include("partials/snippet", data) %>'
);

templates.register(
    'group',
    '<p><%= data.name %></p><% include("person", data) %>'
);

templates.register(
    'partials/snippet',
    '<span>I am <%= data.snippet %></span>'
);