[Experimental] Riot.js templates to PHP transformation

• Quotes are optional: <foo bar={ baz }> becomes <foo bar="{ baz }">.
• Without the <script> tag the JavaScript starts where the last HTML tag ends
• Tag styling (extracted)
• Scoped CSS
• Nested tags
  • Options
  • Yeld
• Mixins
• Expressions
  • { var } becomes <?=$var?>
  • { a() } becomes <?=a()?> (maybe should become <?=$this['a']()?> or <?=$a()?>)
  • { var.value } becomes <?=$var['value']?>
  • { title || 'Untitled' }
  • { results ? 'ready' : 'loading' }
  • { new Date() }
  • { message.length > 140 && 'Message is too long' }
  • { Math.round(rating) }
• Boolean attributes (checked, selected etc..)
  • <input checked={ null }> becomes <input>
  • 44 different boolean attributes
• Class shorthand:
  • class={ completed: done } becomes class="completed" when the value of done is a true value
  • <p class={ foo: true, bar: 0, baz: new Date(), zorro: 'a value' }></p> evaluates to <p class="foo baz zorro"></p>
• Printing brackets
• Customizing curly braces
• Custom tags can be empty, HTML only or JavaScript only
• Conditionals
  • if={ ... }
  • show={ ... }
  • hide={ ... }
• Loops
  • each="{ items }"
  • each="{ name, i in arr }"
  • `each="{ name, value in obj }"
  • no-reorder attr support
  • parent. context
  • Pass the item as an option to the looped tag with data={ ... }
• VIRTUAL tag
• HTML elements as tags
  • <ul riot-tag="my-tag"></ul>
• Server-side rendering

• Pre-processors should be handled by a separate tool
• Complex expressions would require tokenization
• { title || 'Undefined' } or { title && 'Defined' } does not behave as in JavaScript