Fix: HTML nodes being silently dropped in View's Monad instance

[jkasalt]

Hello,

When using >>= directly, or when ApplicativeDo is enabled (which introduces a join call that goes through >>=), all but the last element in a do block would be silently dropped from the rendered HTML.

For example:

{-# LANGUAGE ApplicativeDo #-}
col $ do
  el "One"
  el "Two"
  el "Three"

or

col $ el "One" >>= \_ -> el "Two" >>= \_ -> el "Three"

would render only "Three".

Cause

The >>= implementation of View was extracting only the return value from the first action via (.value) <$> ea, discarding its Html nodes entirely:

View ea >>= famb = View $ do
  a <- (.value) <$> ea   -- nodes from ea are thrown away
  let View eb = famb a
  eb

Fix

Run the first action fully to obtain its Html value, then delegate node accumulation to Html's own >>, which correctly concatenates both node lists:

View ea >>= famb = View $ do
  ha <- ea
  let View eb = famb ha.value
  (ha >>) <$> eb

Notes

The bug was not visible when using plain do notation without ApplicativeDo, because GHC desugars it to >> which is defined as (*>) and bypasses >>= entirely. The bug only manifests when >>= is called directly or through join.