3. Architecture (three-layer IR + universal pivot)

Intent DSL
   ↓ parse
Semantic / Component-Theme IR     … named members (id/class/role/mat_slot/intent_state)
   ↓ resolve (phase evaluation, geometry expansion, theme injection, derived blockstate)
block-array IR                    … voxel grid + palette + block entities + entities [universal pivot]
   ↓ serialize (per edition, version, format backend)
{ .nbt (Java) / .litematic / .schem / .mcstructure (Bedrock) }

3.1 block-array IR = universal pivot

• Every format’s frontend/backend meets at this layer. diff / IoU / serialization happen here.
• It holds a voxel grid + palette + block entities + entities, neutral to format, edition, and version.
• It is the output target of the forward direction and the input destination of the reverse direction (Ecosystem Interop).

3.2 The member / Intent IR is rich and carries invariants

• A named member carries id / class / role / mat_slot / intent_state / resolved_state (Blockstate Model).
• A raw import (schematic ingestion) does not produce a valid Intent IR; it reaches one only after a semantic lift.
• An artifact’s progress is expressed by semantic_level: raw | grouped | lifted.

3.3 Redstone logic sub-layers (Logic / Netlist / Placement IR)

When redstone is described logically (Redstone), three IR layers with distinct roles sit between the Intent IR and the block-array IR (a standard separation in HDL):

Logic IR     logical expressions / dependency DAG (edition-neutral, zero delay)
Netlist IR   cells/nets (logical cell selection; still carries no delay)
Placement IR cell coordinates + actual wire lengths (delay/tick first determined here)

The logic is edition-neutral; the place-and-route result (tiles, timing) is edition-specific. The key point: delay is not carried in Logic/Netlist; it is determined in the Placement IR.

3.4 Consequence of the two-layer model

• The bottom block-array IR is shared (across forward/reverse and all formats).
• The member/Intent IR above it is an independent type with invariants (every member has an intent_state, slots are resolved, etc.).
• This separation lets serialization, diff, lint, and evaluation (IoU) be shared at the bottom layer while keeping the semantic layer type-safe.