web — HTML + validated CSS in one nimony block

A declarative DSL for nimony / Nim 3.0 that builds a typed HTML tree and, inline, validates every style declaration against the MDN grammar and lowers each style: block to a single scoped class. It sits on top of html and css.

Repo → github.com/aoughwl/web

import web

let page = web:
  box:                       # <div>  (`div` is a nimony keyword — `box` spells it)
    attr:
      id: "hero"
    style:
      color: red
      padding: 10.px 20.px
    h1 "Hello, nimony"
    p "HTML + validated CSS, one block."

echo render(page)
# <div id="hero" class="cc9ece13d"><h1>Hello, nimony</h1>…</div>
echo renderStylesheet()
# .cc9ece13d{color:red;padding:10px 20px}
for e in styleErrors(): echo e   # declarations that failed MDN validation

The DSL

Inside a web: block, each line is one of:

form	lowers to
tag: + an indented block	an element with those children
tag "text" (command form)	an element with a single text child
"a bare string"	a text node
attr: block of name: value	attributes on the enclosing element
style: block of prop: value	inline styles → validated via css → one scoped class

Styles are checked against the MDN grammar at build time: anything that fails shows up in styleErrors(), and valid blocks are de-duplicated into scoped classes emitted by renderStylesheet(). The tree itself is the typed html model, so the output is correctly escaped and void-aware.