Clojurians Log v2

Actually, no - the form dropping happens when parsing EDN. When parsing using read et al, it converts constructor forms into tagged literals. That is... interesting.

I think suppress-read is used for reader conditionals for dropping forms after a host branch is detected?

There's some code that suggests that that might be the case:

// When we already have a result, or when the feature didn't match, discard the next form in the reader
try {
  Var.pushThreadBindings(RT.map(RT.SUPPRESS_READ, RT.T));
  form = read(...);

But I can't see anywhere that that flag is actually read in the Lisp reader, except here:

if(isPreserveReadCond(opts) || RT.suppressRead()) {
  return TaggedLiteral.create(sym, form);
} else {
  return sym.getName().contains(".") ? readRecord(form, sym, opts, pendingForms) : readTagged(form, sym, opts, pendingForms);
}

I'm not sure why it's exposed in clojure.core though