REALM Combined Loop: Multi-Size Results Toward Context Compiler

def run(prompt, doc):
    # Document API assumptions:
    # - doc.top_level_ids() -> list[str]
    # - doc.children_ids(section_id) -> list[str]
    # - doc.read_content(section_id) -> str
    # - doc.read_all_content(section_ids) -> str

    visible  = set(doc.top_level_ids())  # "visible section ids"
    expanded = set()                     # prevents re-expanding the same parent
    hidden   = set()                     # hidden once (eligible for second look)
    blocked  = set()                     # hidden twice (final exclude)
    selected = set()                     # OUTPUT: relevant ids
    visited  = set()                     # loop protection

    while True:
        # Termination / resurfacing
        if not visible:
            if not hidden:
                break  # END
            # SHOW: resurface hidden candidates for a second pass
            visible |= (hidden - blocked)

        # READ model chooses next id using only (prompt, visible)
        next_id = READ(prompt, visible)

        # Loop protection: if we ever revisit an id, exit (architecture invariant broken)
        if next_id in visited:
            break  # or raise RuntimeError(f"READ returned already visited id: {next_id}")

        visited.add(next_id)

        # Defensive: if READ returns something not visible, drop it and continue
        if next_id not in visible:
            continue

        # Consume this choice so READ cannot pick it again immediately
        visible.remove(next_id)

        # Expand if it has children (do not run EDIT/ANALYZE on non-leaf)
        children = doc.children_ids(next_id)
        if children:
            if next_id not in expanded:
                expanded.add(next_id)
                # SHOW children, but do not re-add anything already hidden/blocked/selected
                visible |= (set(children) - hidden - blocked - selected)
            continue

        # Leaf section: run EDIT/ANALYZE
        next_content = doc.read_content(next_id)
        content = doc.read_all_content(selected) # all selected content so far
        is_relevant = EDIT_ANALYZE(prompt, next_content, content)

        if is_relevant:
            selected.add(next_id)
            hidden.remove(next_id)  # if it had been hidden before, clear it
            continue

        # Irrelevant leaf: HIDE / BLOCK logic
        if next_id in hidden:
            # Second strike -> BLOCK, and remove from hidden as requested
            hidden.remove(next_id)
            blocked.add(next_id)
        else:
            # First strike -> HIDE
            hidden.add(next_id)

        content = doc.read_all_content(selected) # all selected content so far
        is_done = MONITOR(prompt, content)
        if is_done:
             break

    return selected