Add tagging machinery to assign unique IDs to AST nodes
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
17
lean/Spa/Language/Tagged/Basic.lean
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17
lean/Spa/Language/Tagged/Basic.lean
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import Spa.Language.Base
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import Spa.Language.Tagged.Id
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import Spa.Language.Tagged.Derive
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derive_tagged Spa.Expr Spa.BasicStmt Spa.Stmt
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namespace Spa
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def tagStmt (s : Stmt) : Stmt.Tagged NodeId := (s.tag 0).1
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def Stmt.Tagged.subtreeIds (s : Stmt.Tagged NodeId) : List NodeId :=
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s.foldTags (· :: ·) []
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def Stmt.Tagged.isInLoopBody (body : Stmt.Tagged NodeId) (id : NodeId) : Bool :=
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decide (id ∈ body.subtreeIds)
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end Spa
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417
lean/Spa/Language/Tagged/DESCENDANT-TRACKING.md
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417
lean/Spa/Language/Tagged/DESCENDANT-TRACKING.md
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# Descendant tracking (parked)
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This is the formally-verified **interval-labeling / descendant** machinery that
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used to live in `Id.lean` and `Properties.lean`. It let you decide "is node `a`
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a descendant of node `b`?" with two integer comparisons on their identifiers,
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and *proved* that numeric test equivalent to structural subtree containment.
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It was removed because the descendant test is a *computational optimization*:
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the same question can be answered by walking the AST, and nothing in the current
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pipeline needs the fast test yet. The proofs (a rose-tree flattening + a
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postorder `Good` invariant) are a real mechanization cost to carry. Parked here
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so it can be restored verbatim when LICM actually wants it.
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## What stays in the live code
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- `NodeId` collapses to a single unique index (`{ post : ℕ }`); `tag` still
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assigns each node a distinct postorder number.
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- The bidirectional mapping (`erase`/`tag` + `erase_tagStmt`) stays in
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`Properties.lean`.
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- The labelled-CFG id↔state mapping (`Cfg.lean`) is independent of this and is
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unaffected.
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## Revival checklist
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1. In `Id.lean`, give `NodeId` back its descendant-count field and the test:
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```lean
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structure NodeId where
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post : ℕ
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desc : ℕ -- number of proper descendants (subtree size − 1); leaf = 0
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deriving DecidableEq, Repr
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namespace NodeId
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/-- Left endpoint of the node's postorder interval `[lo, post]`. -/
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def lo (a : NodeId) : ℕ := a.post - a.desc
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/-- `a` is a descendant-or-self of `b`: `a.post` lies in `b`'s interval. -/
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def DescendantOf (a b : NodeId) : Prop := b.lo ≤ a.post ∧ a.post ≤ b.post
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instance (a b : NodeId) : Decidable (DescendantOf a b) := by
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unfold DescendantOf; infer_instance
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end NodeId
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```
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2. In `Derive.lean`, make the generated `tag` store the descendant count again:
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change the emitted identifier in `mkTag` from `(⟨$last⟩ : $nId)` back to
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`(⟨$last, $last - n⟩ : $nId)`.
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3. Paste the Lean block below back into `Properties.lean` (after the round-trip
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theorems). It builds against the `id.lo = lo`-premise form of `Good` and the
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childcount (`desc`) identifier. The headline result is
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`descendant_iff_tagStmt`; everything else is supporting machinery.
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## The parked proofs
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```lean
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/-- A rose tree of identifiers: the uniform shape underlying all three tagged
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AST types, used to reason about the postorder labeling generically. -/
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inductive IdTree where
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| node (id : NodeId) (children : List IdTree)
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namespace IdTree
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def rootId : IdTree → NodeId
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| .node id _ => id
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@[simp] theorem rootId_node (id : NodeId) (cs : List IdTree) :
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(IdTree.node id cs).rootId = id := rfl
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mutual
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def subtrees : IdTree → List IdTree
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| .node id cs => .node id cs :: subtreesList cs
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def subtreesList : List IdTree → List IdTree
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| [] => []
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| c :: cs => subtrees c ++ subtreesList cs
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end
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@[simp] theorem subtrees_node (id : NodeId) (cs : List IdTree) :
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subtrees (.node id cs) = .node id cs :: subtreesList cs := rfl
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@[simp] theorem subtreesList_nil : subtreesList [] = [] := rfl
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@[simp] theorem subtreesList_cons (c : IdTree) (cs : List IdTree) :
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subtreesList (c :: cs) = subtrees c ++ subtreesList cs := rfl
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def posts (t : IdTree) : List ℕ := (subtrees t).map (fun s => s.rootId.post)
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def postsList (cs : List IdTree) : List ℕ := (subtreesList cs).map (fun s => s.rootId.post)
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@[simp] theorem posts_node (id : NodeId) (cs : List IdTree) :
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posts (.node id cs) = id.post :: postsList cs := rfl
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@[simp] theorem postsList_nil : postsList [] = [] := rfl
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@[simp] theorem postsList_cons (c : IdTree) (cs : List IdTree) :
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postsList (c :: cs) = posts c ++ postsList cs := by
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simp [posts, postsList]
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end IdTree
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def Expr.Tagged.toIdTree : Expr.Tagged NodeId → IdTree
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| .add t a b => .node t [a.toIdTree, b.toIdTree]
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| .sub t a b => .node t [a.toIdTree, b.toIdTree]
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| .var t _ => .node t []
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| .num t _ => .node t []
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def BasicStmt.Tagged.toIdTree : BasicStmt.Tagged NodeId → IdTree
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| .assign t _ e => .node t [e.toIdTree]
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| .noop t => .node t []
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def Stmt.Tagged.toIdTree : Stmt.Tagged NodeId → IdTree
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| .basic t bs => .node t [bs.toIdTree]
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| .andThen t a b => .node t [a.toIdTree, b.toIdTree]
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| .ifElse t e a b => .node t [e.toIdTree, a.toIdTree, b.toIdTree]
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| .whileLoop t e s => .node t [e.toIdTree, s.toIdTree]
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mutual
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inductive Good : ℕ → IdTree → Prop
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| mk {lo : ℕ} {id : NodeId} {cs : List IdTree} :
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id.lo = lo → GoodChildren lo cs id.post →
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Good lo (.node id cs)
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inductive GoodChildren : ℕ → List IdTree → ℕ → Prop
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| nil {pos : ℕ} : GoodChildren pos [] pos
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| cons {cur : ℕ} {c : IdTree} {cs : List IdTree} {pos : ℕ} :
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Good cur c → GoodChildren (c.rootId.post + 1) cs pos →
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GoodChildren cur (c :: cs) pos
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end
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theorem Good.lo_le_post {lo : ℕ} {t : IdTree} (h : Good lo t) : lo ≤ t.rootId.post := by
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cases h with
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| mk hlo _ => simp only [NodeId.lo] at hlo; simp only [IdTree.rootId_node]; omega
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theorem GoodChildren.cur_le_pos : ∀ {cur : ℕ} (cs : List IdTree) {pos : ℕ},
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GoodChildren cur cs pos → cur ≤ pos
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| _, [], _, h => by cases h; exact le_rfl
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| _, c :: cs, _, h => by
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cases h with
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| cons hc hcs =>
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have := hc.lo_le_post
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have := GoodChildren.cur_le_pos cs hcs
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omega
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mutual
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theorem Good.mem_posts : ∀ {lo : ℕ} (t : IdTree), Good lo t →
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∀ x, x ∈ IdTree.posts t ↔ lo ≤ x ∧ x ≤ t.rootId.post
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| _, .node id cs, h, x => by
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cases h with
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| mk hlo hch =>
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simp only [IdTree.posts_node, List.mem_cons, IdTree.rootId_node]
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rw [GoodChildren.mem_postsList cs hch x]
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simp only [NodeId.lo] at hlo
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omega
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theorem GoodChildren.mem_postsList : ∀ {cur : ℕ} (cs : List IdTree) {pos : ℕ},
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GoodChildren cur cs pos → ∀ x, x ∈ IdTree.postsList cs ↔ cur ≤ x ∧ x < pos
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| _, [], _, h, x => by
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cases h
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simp only [IdTree.postsList_nil]
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constructor
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· intro hx; exact absurd hx (List.not_mem_nil x)
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· rintro ⟨h1, h2⟩; exfalso; omega
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| _, c :: cs, _, h, x => by
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cases h with
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| cons hc hcs =>
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simp only [IdTree.postsList_cons, List.mem_append]
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rw [Good.mem_posts c hc x, GoodChildren.mem_postsList cs hcs x]
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have := hc.lo_le_post
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have := GoodChildren.cur_le_pos cs hcs
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omega
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end
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mutual
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theorem Good.nodup_posts : ∀ {lo : ℕ} (t : IdTree), Good lo t → (IdTree.posts t).Nodup
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| _, .node id cs, h => by
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cases h with
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| mk hlo hch =>
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simp only [IdTree.posts_node, List.nodup_cons]
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refine ⟨?_, GoodChildren.nodup_postsList cs hch⟩
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intro hmem
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rw [GoodChildren.mem_postsList cs hch id.post] at hmem
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omega
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theorem GoodChildren.nodup_postsList : ∀ {cur : ℕ} (cs : List IdTree) {pos : ℕ},
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GoodChildren cur cs pos → (IdTree.postsList cs).Nodup
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| _, [], _, h => by cases h; simp only [IdTree.postsList_nil, List.nodup_nil]
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| _, c :: cs, _, h => by
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cases h with
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| cons hc hcs =>
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simp only [IdTree.postsList_cons, List.nodup_append]
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refine ⟨Good.nodup_posts c hc, GoodChildren.nodup_postsList cs hcs, ?_⟩
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intro x hx1 hx2
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rw [Good.mem_posts c hc x] at hx1
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rw [GoodChildren.mem_postsList cs hcs x] at hx2
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omega
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end
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mutual
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theorem Good.subtree_good : ∀ {lo : ℕ} (t : IdTree), Good lo t →
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∀ s ∈ IdTree.subtrees t, Good s.rootId.lo s
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| _, .node id cs, h, s, hs => by
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cases h with
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| mk hlo hch =>
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rw [IdTree.subtrees_node, List.mem_cons] at hs
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rcases hs with rfl | hs
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· simp only [IdTree.rootId_node]; rw [hlo]; exact Good.mk hlo hch
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· exact GoodChildren.subtree_good cs hch s hs
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theorem GoodChildren.subtree_good : ∀ {cur : ℕ} (cs : List IdTree) {pos : ℕ},
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GoodChildren cur cs pos → ∀ s ∈ IdTree.subtreesList cs, Good s.rootId.lo s
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| _, [], _, _, s, hs => by simp only [IdTree.subtreesList_nil, List.not_mem_nil] at hs
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| _, c :: cs, _, h, s, hs => by
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cases h with
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| cons hc hcs =>
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rw [IdTree.subtreesList_cons, List.mem_append] at hs
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rcases hs with hs | hs
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· exact Good.subtree_good c hc s hs
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· exact GoodChildren.subtree_good cs hcs s hs
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end
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mutual
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theorem IdTree.subtrees_subset : ∀ (t : IdTree) {b : IdTree},
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b ∈ subtrees t → subtrees b ⊆ subtrees t
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| .node id cs, b, hb => by
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rw [subtrees_node, List.mem_cons] at hb
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rcases hb with rfl | hb
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· exact fun _ h => h
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· intro x hx
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rw [subtrees_node, List.mem_cons]
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exact Or.inr (IdTree.subtreesList_subset cs hb hx)
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theorem IdTree.subtreesList_subset : ∀ (cs : List IdTree) {b : IdTree},
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b ∈ subtreesList cs → subtrees b ⊆ subtreesList cs
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| [], b, hb => by simp only [subtreesList_nil, List.not_mem_nil] at hb
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| c :: cs, b, hb => by
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rw [subtreesList_cons, List.mem_append] at hb
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intro x hx
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rw [subtreesList_cons, List.mem_append]
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rcases hb with hb | hb
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· exact Or.inl (IdTree.subtrees_subset c hb hx)
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· exact Or.inr (IdTree.subtreesList_subset cs hb hx)
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end
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theorem IdTree.eq_of_post_eq {l : List IdTree}
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(h : (l.map (fun s => s.rootId.post)).Nodup) {a c : IdTree}
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(ha : a ∈ l) (hc : c ∈ l) (hpost : a.rootId.post = c.rootId.post) : a = c := by
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induction l with
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| nil => exact absurd ha (List.not_mem_nil a)
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| cons d ds ih =>
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simp only [List.map_cons, List.nodup_cons] at h
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obtain ⟨hd, htl⟩ := h
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simp only [List.mem_cons] at ha hc
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rcases ha with rfl | ha <;> rcases hc with rfl | hc
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· rfl
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· exfalso; apply hd; rw [hpost]; exact List.mem_map_of_mem _ hc
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· exfalso; apply hd; rw [← hpost]; exact List.mem_map_of_mem _ ha
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· exact ih htl ha hc
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theorem descendant_iff_of_good {lo : ℕ} {t : IdTree} (hg : Good lo t)
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{a b : IdTree} (ha : a ∈ IdTree.subtrees t) (hb : b ∈ IdTree.subtrees t) :
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a.rootId.DescendantOf b.rootId ↔ a ∈ IdTree.subtrees b := by
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have hgb : Good b.rootId.lo b := Good.subtree_good t hg b hb
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constructor
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· rintro ⟨h1, h2⟩
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have hmem : a.rootId.post ∈ IdTree.posts b := by
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rw [Good.mem_posts b hgb a.rootId.post]; exact ⟨h1, h2⟩
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rw [IdTree.posts, List.mem_map] at hmem
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obtain ⟨c, hc_mem, hc_post⟩ := hmem
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have hc_t : c ∈ IdTree.subtrees t := IdTree.subtrees_subset t hb hc_mem
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have hac : a = c :=
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IdTree.eq_of_post_eq (hg.nodup_posts t) ha hc_t hc_post.symm
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rw [hac]; exact hc_mem
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· intro hsub
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have hmem : a.rootId.post ∈ IdTree.posts b := by
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rw [IdTree.posts, List.mem_map]; exact ⟨a, hsub, rfl⟩
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rw [Good.mem_posts b hgb a.rootId.post] at hmem
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exact hmem
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/-! ### Tagging produces a good tree
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We bridge from the `tag` traversal to the abstract `Good` invariant, by induction
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on the plain AST. Each lemma also records that the returned counter is one past
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the root's postorder index. -/
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theorem Expr.tag_spec : ∀ (e : Expr) (n : ℕ),
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Good n (e.tag n).1.toIdTree ∧ (e.tag n).1.toIdTree.rootId.post + 1 = (e.tag n).2 := by
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intro e
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induction e with
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| num k =>
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intro n
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refine ⟨?_, ?_⟩
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· simp only [Expr.tag, Expr.Tagged.toIdTree]
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exact Good.mk (by simp only [NodeId.lo]; omega) GoodChildren.nil
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· simp only [Expr.tag, Expr.Tagged.toIdTree, IdTree.rootId_node]
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| var x =>
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intro n
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refine ⟨?_, ?_⟩
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· simp only [Expr.tag, Expr.Tagged.toIdTree]
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exact Good.mk (by simp only [NodeId.lo]; omega) GoodChildren.nil
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· simp only [Expr.tag, Expr.Tagged.toIdTree, IdTree.rootId_node]
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| add a b iha ihb =>
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intro n
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obtain ⟨gA, pA⟩ := iha n
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obtain ⟨gB, pB⟩ := ihb (a.tag n).2
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have lA := gA.lo_le_post
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have lB := gB.lo_le_post
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refine ⟨?_, ?_⟩
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· simp only [Expr.tag, Expr.Tagged.toIdTree]
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refine Good.mk ?_ ?_
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· simp only [NodeId.lo]; omega
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· refine GoodChildren.cons gA ?_
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rw [pA]; refine GoodChildren.cons gB ?_; rw [pB]; exact GoodChildren.nil
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· simp only [Expr.tag, Expr.Tagged.toIdTree, IdTree.rootId_node]
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| sub a b iha ihb =>
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intro n
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obtain ⟨gA, pA⟩ := iha n
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obtain ⟨gB, pB⟩ := ihb (a.tag n).2
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have lA := gA.lo_le_post
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have lB := gB.lo_le_post
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refine ⟨?_, ?_⟩
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· simp only [Expr.tag, Expr.Tagged.toIdTree]
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refine Good.mk ?_ ?_
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· simp only [NodeId.lo]; omega
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· refine GoodChildren.cons gA ?_
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rw [pA]; refine GoodChildren.cons gB ?_; rw [pB]; exact GoodChildren.nil
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· simp only [Expr.tag, Expr.Tagged.toIdTree, IdTree.rootId_node]
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theorem BasicStmt.tag_spec : ∀ (bs : BasicStmt) (n : ℕ),
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Good n (bs.tag n).1.toIdTree ∧ (bs.tag n).1.toIdTree.rootId.post + 1 = (bs.tag n).2 := by
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intro bs
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cases bs with
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| noop =>
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intro n
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refine ⟨?_, ?_⟩
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· simp only [BasicStmt.tag, BasicStmt.Tagged.toIdTree]
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exact Good.mk (by simp only [NodeId.lo]; omega) GoodChildren.nil
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· simp only [BasicStmt.tag, BasicStmt.Tagged.toIdTree, IdTree.rootId_node]
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| assign x e =>
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intro n
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obtain ⟨gE, pE⟩ := Expr.tag_spec e n
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have lE := gE.lo_le_post
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refine ⟨?_, ?_⟩
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· simp only [BasicStmt.tag, BasicStmt.Tagged.toIdTree]
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refine Good.mk ?_ ?_
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· simp only [NodeId.lo]; omega
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· refine GoodChildren.cons gE ?_
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rw [pE]; exact GoodChildren.nil
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· simp only [BasicStmt.tag, BasicStmt.Tagged.toIdTree, IdTree.rootId_node]
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theorem Stmt.tag_spec : ∀ (s : Stmt) (n : ℕ),
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Good n (s.tag n).1.toIdTree ∧ (s.tag n).1.toIdTree.rootId.post + 1 = (s.tag n).2 := by
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intro s
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induction s with
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| basic bs =>
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intro n
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obtain ⟨gBs, pBs⟩ := BasicStmt.tag_spec bs n
|
||||
have lBs := gBs.lo_le_post
|
||||
refine ⟨?_, ?_⟩
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree]
|
||||
refine Good.mk ?_ ?_
|
||||
· simp only [NodeId.lo]; omega
|
||||
· refine GoodChildren.cons gBs ?_
|
||||
rw [pBs]; exact GoodChildren.nil
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree, IdTree.rootId_node]
|
||||
| andThen a b iha ihb =>
|
||||
intro n
|
||||
obtain ⟨gA, pA⟩ := iha n
|
||||
obtain ⟨gB, pB⟩ := ihb (a.tag n).2
|
||||
have lA := gA.lo_le_post
|
||||
have lB := gB.lo_le_post
|
||||
refine ⟨?_, ?_⟩
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree]
|
||||
refine Good.mk ?_ ?_
|
||||
· simp only [NodeId.lo]; omega
|
||||
· refine GoodChildren.cons gA ?_
|
||||
rw [pA]; refine GoodChildren.cons gB ?_; rw [pB]; exact GoodChildren.nil
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree, IdTree.rootId_node]
|
||||
| ifElse e a b iha ihb =>
|
||||
intro n
|
||||
obtain ⟨gE, pE⟩ := Expr.tag_spec e n
|
||||
obtain ⟨gA, pA⟩ := iha (e.tag n).2
|
||||
obtain ⟨gB, pB⟩ := ihb (a.tag (e.tag n).2).2
|
||||
have lE := gE.lo_le_post
|
||||
have lA := gA.lo_le_post
|
||||
have lB := gB.lo_le_post
|
||||
refine ⟨?_, ?_⟩
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree]
|
||||
refine Good.mk ?_ ?_
|
||||
· simp only [NodeId.lo]; omega
|
||||
· refine GoodChildren.cons gE ?_
|
||||
rw [pE]; refine GoodChildren.cons gA ?_
|
||||
rw [pA]; refine GoodChildren.cons gB ?_; rw [pB]; exact GoodChildren.nil
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree, IdTree.rootId_node]
|
||||
| whileLoop e s ih =>
|
||||
intro n
|
||||
obtain ⟨gE, pE⟩ := Expr.tag_spec e n
|
||||
obtain ⟨gS, pS⟩ := ih (e.tag n).2
|
||||
have lE := gE.lo_le_post
|
||||
have lS := gS.lo_le_post
|
||||
refine ⟨?_, ?_⟩
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree]
|
||||
refine Good.mk ?_ ?_
|
||||
· simp only [NodeId.lo]; omega
|
||||
· refine GoodChildren.cons gE ?_
|
||||
rw [pE]; refine GoodChildren.cons gS ?_; rw [pS]; exact GoodChildren.nil
|
||||
· simp only [Stmt.tag, Stmt.Tagged.toIdTree, IdTree.rootId_node]
|
||||
|
||||
/-- A freshly tagged program is a well-tagged tree (rooted at postorder start `0`). -/
|
||||
theorem good_tagStmt (s : Stmt) : Good 0 (tagStmt s).toIdTree :=
|
||||
(Stmt.tag_spec s 0).1
|
||||
|
||||
/-- **Descendant characterization.** The numeric `NodeId.DescendantOf` relation on
|
||||
two nodes of a tagged program holds exactly when one is structurally contained in
|
||||
the other's subtree. -/
|
||||
theorem descendant_iff_tagStmt (s : Stmt) {a b : IdTree}
|
||||
(ha : a ∈ IdTree.subtrees (tagStmt s).toIdTree)
|
||||
(hb : b ∈ IdTree.subtrees (tagStmt s).toIdTree) :
|
||||
a.rootId.DescendantOf b.rootId ↔ a ∈ IdTree.subtrees b :=
|
||||
descendant_iff_of_good (good_tagStmt s) ha hb
|
||||
```
|
||||
241
lean/Spa/Language/Tagged/Derive.lean
Normal file
241
lean/Spa/Language/Tagged/Derive.lean
Normal file
@@ -0,0 +1,241 @@
|
||||
import Lean
|
||||
import Mathlib.Tactic.DeriveTraversable
|
||||
import Spa.Language.Base
|
||||
import Spa.Language.Tagged.Id
|
||||
|
||||
/-!
|
||||
# The `derive_tagged` command
|
||||
|
||||
`derive_tagged T₁ T₂ … Tₙ` takes a family of (possibly mutually recursive)
|
||||
inductive types and generates, for each `Tᵢ`:
|
||||
|
||||
* a *tagged* mirror inductive `Tᵢ.Tagged (τ : Type)`, in which every constructor
|
||||
carries a leading `tag : τ` field and every field whose type is a family
|
||||
member is retyped to its `.Tagged τ` counterpart;
|
||||
* `Tᵢ.Tagged.erase : Tᵢ.Tagged τ → Tᵢ`, forgetting all tags;
|
||||
* `Tᵢ.tag : Tᵢ → ℕ → Tᵢ.Tagged NodeId × ℕ`, assigning every node a unique
|
||||
`NodeId` (its postorder index) by a single unified traversal that threads a
|
||||
counter; the whole family shares one counter, so identifiers are unique across
|
||||
types.
|
||||
|
||||
The generated declarations have exactly the shape of the hand-written reference;
|
||||
see `Spa/Language/Tagged/Basic.lean` (which invokes this command) and the proofs
|
||||
in `Spa/Language/Tagged/Properties.lean`.
|
||||
|
||||
Scope: the generator handles non-indexed inductives whose constructor fields are
|
||||
either scalars or *direct* references to a family member (which covers the object
|
||||
language). Nested occurrences such as `List Tᵢ` are not supported.
|
||||
-/
|
||||
|
||||
open Lean Elab Command Meta
|
||||
|
||||
namespace Spa.DeriveTagged
|
||||
|
||||
/-- One constructor field, classified as a recursive family reference or a scalar
|
||||
(whose type syntax we keep verbatim for the mirror inductive). -/
|
||||
structure FieldData where
|
||||
isRec : Bool
|
||||
recType : Name
|
||||
typeStx : Term
|
||||
|
||||
/-- A constructor: its original (full) name, short name, and fields. -/
|
||||
structure CtorData where
|
||||
origName : Name
|
||||
shortName : Name
|
||||
fields : Array FieldData
|
||||
|
||||
/-- A family member together with its constructors. -/
|
||||
structure TypeData where
|
||||
name : Name
|
||||
ctors : Array CtorData
|
||||
|
||||
def taggedOf (n : Name) : Name := n ++ `Tagged
|
||||
def eraseOf (n : Name) : Name := n ++ `Tagged ++ `erase
|
||||
def rootTagOf (n : Name) : Name := n ++ `Tagged ++ `rootTag
|
||||
def tagOf (n : Name) : Name := n ++ `tag
|
||||
def foldTagsOf (n : Name) : Name := n ++ `Tagged ++ `foldTags
|
||||
|
||||
/-- Inspect the family, classifying each constructor field. -/
|
||||
def gather (family : Array Name) (τ : Ident) : TermElabM (Array TypeData) := do
|
||||
let famSet : NameSet := family.foldl (·.insert ·) {}
|
||||
family.mapM fun tn => do
|
||||
let iv ← getConstInfoInduct tn
|
||||
let ctors ← iv.ctors.toArray.mapM fun cn => do
|
||||
let cv ← getConstInfoCtor cn
|
||||
let fields ← forallTelescopeReducing cv.type fun args _ => do
|
||||
let fieldArgs := args.extract iv.numParams args.size
|
||||
fieldArgs.mapM fun a => do
|
||||
let ty ← inferType a
|
||||
match ty.getAppFn.constName? with
|
||||
| some hn =>
|
||||
if famSet.contains hn then
|
||||
return { isRec := true, recType := hn, typeStx := ← `($(mkIdent (taggedOf hn)) $τ) }
|
||||
else
|
||||
return { isRec := false, recType := default, typeStx := ← Lean.PrettyPrinter.delab ty }
|
||||
| none =>
|
||||
return { isRec := false, recType := default, typeStx := ← Lean.PrettyPrinter.delab ty }
|
||||
return { origName := cn, shortName := cn.componentsRev.head!, fields }
|
||||
return { name := tn, ctors }
|
||||
|
||||
/-- The arrow type `τ → <fields…> → Self τ` of a tagged constructor. -/
|
||||
def ctorArrow (cd : CtorData) (self : Term) (τ : Ident) : TermElabM Term := do
|
||||
let mut t := self
|
||||
for f in cd.fields.reverse do
|
||||
t ← `($(f.typeStx) → $t)
|
||||
`($τ → $t)
|
||||
|
||||
/-- The tagged mirror inductives, one per family member. The family is a DAG
|
||||
(`Expr ← BasicStmt ← Stmt`), not genuinely mutual, so they are emitted as
|
||||
separate inductives in dependency order rather than a `mutual` block.
|
||||
|
||||
`Functor`/`Traversable` instances are derived separately by `mkDeriveInstances`
|
||||
below rather than via an inline `deriving` clause. -/
|
||||
def mkInductives (tds : Array TypeData) (τ : Ident) :
|
||||
CommandElabM (Array (TSyntax `command)) := do
|
||||
tds.mapM fun td => do
|
||||
let self ← `($(mkIdent (taggedOf td.name)) $τ)
|
||||
let ctors ← td.ctors.mapM fun cd => do
|
||||
let aty ← Command.liftTermElabM (ctorArrow cd self τ)
|
||||
`(Lean.Parser.Command.ctor| | $(mkIdent cd.shortName):ident : $aty)
|
||||
`(command| inductive $(mkIdent (taggedOf td.name)):ident ($τ : Type) where $ctors*)
|
||||
|
||||
/-- A `deriving instance Functor, Traversable for Tᵢ.Tagged` command per family
|
||||
member. Since every tagged type is a single-parameter, direct-recursive
|
||||
inductive in `τ`, Mathlib's deriving handler produces clean (`sorry`-free)
|
||||
instances, giving `map`, `traverse`, and the `Traversable.foldr`/`toList` folds
|
||||
for free.
|
||||
|
||||
These are emitted as *separate* commands in dependency order (rather than an
|
||||
inline `deriving` clause on each inductive) for two reasons: deriving
|
||||
`Stmt.Tagged` needs the `Expr.Tagged`/`BasicStmt.Tagged` instances already in
|
||||
scope, and — because every member's type name ends in `.Tagged` — the handler's
|
||||
auto-generated instance name (`instFunctorTagged`, built from the type's last
|
||||
component) collides across the family unless each derive sees the environment
|
||||
the previous one updated; separate commands give it that, so the names
|
||||
disambiguate to `instFunctorTagged`, `instFunctorTagged_1`, ….
|
||||
|
||||
The hand-written `foldTags` is retained alongside these: it is a
|
||||
structural-recursion fold that `simp`/`decide` reduce cleanly, unlike the
|
||||
abstract `Traversable.foldr` (defined via the `FreeMonoid`/`Const` applicative),
|
||||
which reduces under `decide`/`rfl` but not naive `simp` unfolding. -/
|
||||
def mkDeriveInstances (tds : Array TypeData) : CommandElabM (Array (TSyntax `command)) := do
|
||||
tds.mapM fun td =>
|
||||
`(command| deriving instance Functor, Traversable for $(mkIdent (taggedOf td.name)))
|
||||
|
||||
/-- The `erase` functions, one per family member (separate defs in dependency
|
||||
order — each calls only already-defined lower members). -/
|
||||
def mkErase (tds : Array TypeData) : CommandElabM (Array (TSyntax `command)) := do
|
||||
tds.mapM fun td => do
|
||||
let mut pats : Array Term := #[]
|
||||
let mut rhss : Array Term := #[]
|
||||
for cd in td.ctors do
|
||||
let argNames := (Array.range cd.fields.size).map (fun i => mkIdent (.mkSimple s!"a{i}"))
|
||||
let pat ← `($(mkIdent (taggedOf td.name ++ cd.shortName)) _ $argNames*)
|
||||
let eraseArgs ← (cd.fields.zip argNames).mapM fun (f, a) =>
|
||||
if f.isRec then `($(mkIdent (eraseOf f.recType)) $a) else pure a
|
||||
let rhs ← `($(mkIdent cd.origName) $eraseArgs*)
|
||||
pats := pats.push pat
|
||||
rhss := rhss.push rhs
|
||||
`(command| def $(mkIdent (eraseOf td.name)) {τ : Type} :
|
||||
$(mkIdent (taggedOf td.name)) τ → $(mkIdent td.name) :=
|
||||
fun x => match x with $[| $pats => $rhss]*)
|
||||
|
||||
/-- The `rootTag` accessors (one non-recursive `def` per type). -/
|
||||
def mkRootTag (tds : Array TypeData) : CommandElabM (Array (TSyntax `command)) := do
|
||||
let tIdent := mkIdent `t
|
||||
tds.mapM fun td => do
|
||||
let mut pats : Array Term := #[]
|
||||
let mut rhss : Array Term := #[]
|
||||
for cd in td.ctors do
|
||||
let hole ← `(_)
|
||||
let wilds := Array.mkArray cd.fields.size hole
|
||||
pats := pats.push (← `($(mkIdent (taggedOf td.name ++ cd.shortName)) $tIdent $wilds*))
|
||||
rhss := rhss.push tIdent
|
||||
`(command| def $(mkIdent (rootTagOf td.name)) {τ : Type} :
|
||||
$(mkIdent (taggedOf td.name)) τ → τ :=
|
||||
fun x => match x with $[| $pats => $rhss]*)
|
||||
|
||||
/-- The postorder `tag` functions, one per family member (separate defs in
|
||||
dependency order). -/
|
||||
def mkTag (tds : Array TypeData) : CommandElabM (Array (TSyntax `command)) := do
|
||||
let nId := mkIdent ``Spa.NodeId
|
||||
tds.mapM fun td => do
|
||||
let mut pats : Array Term := #[]
|
||||
let mut rhss : Array Term := #[]
|
||||
for cd in td.ctors do
|
||||
let argNames := (Array.range cd.fields.size).map (fun i => mkIdent (.mkSimple s!"a{i}"))
|
||||
let pat ← `($(mkIdent cd.origName) $argNames*)
|
||||
let mut cur : Term ← `(n)
|
||||
let mut lets : Array (Ident × Term) := #[]
|
||||
let mut taggedArgs : Array Term := #[]
|
||||
let mut ri := 0
|
||||
for (f, a) in cd.fields.zip argNames do
|
||||
if f.isRec then
|
||||
let rName := mkIdent (.mkSimple s!"r{ri}")
|
||||
let rhsCall ← `($(mkIdent (tagOf f.recType)) $a $cur)
|
||||
lets := lets.push (rName, rhsCall)
|
||||
taggedArgs := taggedArgs.push (← `($rName |>.1))
|
||||
cur ← `($rName |>.2)
|
||||
ri := ri + 1
|
||||
else
|
||||
taggedArgs := taggedArgs.push a
|
||||
let last := cur
|
||||
let tagged ← `($(mkIdent (taggedOf td.name ++ cd.shortName))
|
||||
(⟨$last⟩ : $nId) $taggedArgs*)
|
||||
let mut body ← `(($tagged, $last + 1))
|
||||
for (rName, rhs) in lets.reverse do
|
||||
body ← `(let $rName := $rhs; $body)
|
||||
pats := pats.push pat
|
||||
rhss := rhss.push body
|
||||
`(command| def $(mkIdent (tagOf td.name)) :
|
||||
$(mkIdent td.name) → Nat → $(mkIdent (taggedOf td.name)) $nId × Nat :=
|
||||
fun e n => match e with $[| $pats => $rhss]*)
|
||||
|
||||
/-- The tag-fold functions: `foldTags f acc t` applies `f` to every tag in `t`,
|
||||
right-to-left, threading `acc`. This is the `Foldable`/`foldr`-over-tags the
|
||||
hand-written collectors (e.g. `subtreeIds`) reduce to. One separate def per
|
||||
family member (the family is a DAG, so no `mutual` block is needed). -/
|
||||
def mkFoldTags (tds : Array TypeData) : CommandElabM (Array (TSyntax `command)) := do
|
||||
let τ := mkIdent `τ
|
||||
let m := mkIdent `M
|
||||
let fId := mkIdent `f
|
||||
let accId := mkIdent `acc
|
||||
let tagId := mkIdent `t
|
||||
tds.mapM fun td => do
|
||||
let mut pats : Array Term := #[]
|
||||
let mut rhss : Array Term := #[]
|
||||
for cd in td.ctors do
|
||||
let argNames := (Array.range cd.fields.size).map (fun i => mkIdent (.mkSimple s!"a{i}"))
|
||||
let pat ← `($(mkIdent (taggedOf td.name ++ cd.shortName)) $tagId $argNames*)
|
||||
let mut body : Term := accId
|
||||
for (fld, a) in (cd.fields.zip argNames).reverse do
|
||||
if fld.isRec then
|
||||
body ← `($(mkIdent (foldTagsOf fld.recType)) $fId $body $a)
|
||||
body ← `($fId $tagId $body)
|
||||
pats := pats.push pat
|
||||
rhss := rhss.push body
|
||||
`(command| def $(mkIdent (foldTagsOf td.name)) {$τ:ident : Type} {$m:ident : Type}
|
||||
($fId : $τ → $m → $m) ($accId : $m) :
|
||||
$(mkIdent (taggedOf td.name)) $τ → $m :=
|
||||
fun x => match x with $[| $pats => $rhss]*)
|
||||
|
||||
/-- `derive_tagged T₁ … Tₙ` — generate tagged mirrors, `erase`, and `tag` for the
|
||||
given family of inductives. -/
|
||||
syntax (name := deriveTaggedCmd) "derive_tagged " ident+ : command
|
||||
|
||||
@[command_elab deriveTaggedCmd]
|
||||
def elabDeriveTagged : CommandElab := fun stx => do
|
||||
match stx with
|
||||
| `(derive_tagged $ids*) =>
|
||||
let family ← ids.mapM fun i => Command.liftCoreM (realizeGlobalConstNoOverload i)
|
||||
let τ := mkIdent `τ
|
||||
let tds ← Command.liftTermElabM (gather family τ)
|
||||
for d in (← mkInductives tds τ) do elabCommand d
|
||||
for d in (← mkDeriveInstances tds) do elabCommand d
|
||||
for d in (← mkRootTag tds) do elabCommand d
|
||||
for d in (← mkErase tds) do elabCommand d
|
||||
for d in (← mkTag tds) do elabCommand d
|
||||
for d in (← mkFoldTags tds) do elabCommand d
|
||||
| _ => throwUnsupportedSyntax
|
||||
|
||||
end Spa.DeriveTagged
|
||||
63
lean/Spa/Language/Tagged/Graphs.lean
Normal file
63
lean/Spa/Language/Tagged/Graphs.lean
Normal file
@@ -0,0 +1,63 @@
|
||||
import Spa.Language
|
||||
import Spa.Language.Graphs
|
||||
import Spa.Language.Tagged.Basic
|
||||
import Spa.Language.Tagged.Properties
|
||||
|
||||
namespace Spa
|
||||
|
||||
open GGraph
|
||||
|
||||
def Stmt.Tagged.cfg : Stmt.Tagged NodeId → GGraph (List (BasicStmt.Tagged NodeId))
|
||||
| .basic _ bs => GGraph.singleton [bs]
|
||||
| .andThen _ s₁ s₂ => s₁.cfg ⤳ s₂.cfg
|
||||
| .ifElse _ _ s₁ s₂ => s₁.cfg ∙ s₂.cfg
|
||||
| .whileLoop _ _ s => GGraph.loop s.cfg
|
||||
|
||||
theorem Stmt.Tagged.cfg_graph : ∀ (t : Stmt.Tagged NodeId),
|
||||
t.cfg.map (List.map BasicStmt.Tagged.erase) = t.erase.cfg
|
||||
| .basic _ bs => by simp [Stmt.Tagged.cfg, Stmt.cfg, Stmt.Tagged.erase, BasicStmt.Tagged.erase]
|
||||
| .andThen _ s₁ s₂ => by
|
||||
simp [Stmt.Tagged.cfg, Stmt.cfg, Stmt.Tagged.erase, Stmt.Tagged.cfg_graph s₁, Stmt.Tagged.cfg_graph s₂]
|
||||
| .ifElse _ _ s₁ s₂ => by
|
||||
simp [Stmt.Tagged.cfg, Stmt.cfg, Stmt.Tagged.erase, Stmt.Tagged.cfg_graph s₁, Stmt.Tagged.cfg_graph s₂]
|
||||
| .whileLoop _ _ s => by
|
||||
simp [Stmt.Tagged.cfg, Stmt.cfg, Stmt.Tagged.erase, Stmt.Tagged.cfg_graph s]
|
||||
|
||||
def GGraph.nodeLabel (g : GGraph (List (BasicStmt.Tagged NodeId))) (i : g.Index) : Option NodeId :=
|
||||
(g.nodes i).head?.map BasicStmt.Tagged.rootTag
|
||||
|
||||
def GGraph.stateOf (g : GGraph (List (BasicStmt.Tagged NodeId))) (id : NodeId) : Option g.Index :=
|
||||
g.indices.find? (fun i => decide (g.nodeLabel i = some id))
|
||||
|
||||
theorem GGraph.stateOf_label {g : GGraph (List (BasicStmt.Tagged NodeId))} {id : NodeId}
|
||||
{i : g.Index} (h : g.stateOf id = some i) : g.nodeLabel i = some id := by
|
||||
rw [GGraph.stateOf] at h
|
||||
simpa using List.find?_some h
|
||||
|
||||
namespace Program
|
||||
|
||||
variable (p : Program)
|
||||
|
||||
def tagged : Stmt.Tagged NodeId := tagStmt p.rootStmt
|
||||
|
||||
def taggedCfg : GGraph (List (BasicStmt.Tagged NodeId)) :=
|
||||
GGraph.wrap p.tagged.cfg
|
||||
|
||||
theorem taggedCfg_erase :
|
||||
p.taggedCfg.map (List.map BasicStmt.Tagged.erase) = p.cfg := by
|
||||
rw [taggedCfg, GGraph.map_wrap, Stmt.Tagged.cfg_graph, tagged, erase_tagStmt]
|
||||
rfl
|
||||
|
||||
theorem taggedCfg_size : p.taggedCfg.size = p.cfg.size := by
|
||||
conv_rhs => rw [← p.taggedCfg_erase]
|
||||
rfl
|
||||
|
||||
def nodeIdOf (s : p.State) : Option NodeId :=
|
||||
p.taggedCfg.nodeLabel (Fin.cast p.taggedCfg_size.symm s)
|
||||
|
||||
def stateOfNodeId (id : NodeId) : Option p.State :=
|
||||
(p.taggedCfg.stateOf id).map (Fin.cast p.taggedCfg_size)
|
||||
|
||||
end Program
|
||||
|
||||
end Spa
|
||||
9
lean/Spa/Language/Tagged/Id.lean
Normal file
9
lean/Spa/Language/Tagged/Id.lean
Normal file
@@ -0,0 +1,9 @@
|
||||
import Mathlib.Data.Nat.Notation
|
||||
|
||||
namespace Spa
|
||||
|
||||
structure NodeId where
|
||||
post : ℕ
|
||||
deriving DecidableEq, Repr
|
||||
|
||||
end Spa
|
||||
29
lean/Spa/Language/Tagged/Properties.lean
Normal file
29
lean/Spa/Language/Tagged/Properties.lean
Normal file
@@ -0,0 +1,29 @@
|
||||
import Spa.Language.Tagged.Basic
|
||||
|
||||
namespace Spa
|
||||
|
||||
@[simp] theorem Expr.erase_tag (e : Expr) (n : ℕ) : (e.tag n).1.erase = e := by
|
||||
induction e generalizing n with
|
||||
| add a b iha ihb => simp [Expr.tag, Expr.Tagged.erase, iha, ihb]
|
||||
| sub a b iha ihb => simp [Expr.tag, Expr.Tagged.erase, iha, ihb]
|
||||
| var x => simp [Expr.tag, Expr.Tagged.erase]
|
||||
| num k => simp [Expr.tag, Expr.Tagged.erase]
|
||||
|
||||
@[simp] theorem BasicStmt.erase_tag (bs : BasicStmt) (n : ℕ) :
|
||||
(bs.tag n).1.erase = bs := by
|
||||
cases bs with
|
||||
| assign x e => simp [BasicStmt.tag, BasicStmt.Tagged.erase]
|
||||
| noop => simp [BasicStmt.tag, BasicStmt.Tagged.erase]
|
||||
|
||||
@[simp] theorem Stmt.erase_tag (s : Stmt) (n : ℕ) : (s.tag n).1.erase = s := by
|
||||
induction s generalizing n with
|
||||
| basic bs => simp [Stmt.tag, Stmt.Tagged.erase]
|
||||
| andThen a b iha ihb => simp [Stmt.tag, Stmt.Tagged.erase, iha, ihb]
|
||||
| ifElse e a b iha ihb => simp [Stmt.tag, Stmt.Tagged.erase, iha, ihb]
|
||||
| whileLoop e s ih => simp [Stmt.tag, Stmt.Tagged.erase, ih]
|
||||
|
||||
/-- Erasing a freshly tagged program recovers it. -/
|
||||
theorem erase_tagStmt (s : Stmt) : (tagStmt s).erase = s := by
|
||||
simp [tagStmt]
|
||||
|
||||
end Spa
|
||||
46
lean/Spa/Language/Tagged/TODO.md
Normal file
46
lean/Spa/Language/Tagged/TODO.md
Normal file
@@ -0,0 +1,46 @@
|
||||
# Tagged AST — follow-ups
|
||||
|
||||
## Descendant tracking — parked
|
||||
|
||||
The interval-labeling descendant test and its correctness proof
|
||||
(`descendant_iff_tagStmt` and supporting rose-tree/`Good` machinery) have been
|
||||
removed from the live code and parked in `DESCENDANT-TRACKING.md`, with a revival
|
||||
checklist. It's a computational optimization not yet needed; revive it (and the
|
||||
`NodeId.desc` field) when LICM wants fast ancestor queries.
|
||||
|
||||
## ID → CFG-state mapping — plan part B — DONE
|
||||
|
||||
`Graphs.lean` now defines a payload-generic `GGraph α` (with `Graph := GGraph
|
||||
(List BasicStmt)` as the concrete CFG), so the labelled CFG **reuses** the graph
|
||||
combinators instead of mirroring them. In `Cfg.lean`:
|
||||
`buildCfgL : Stmt.Tagged NodeId → GGraph (List (BasicStmt.Tagged NodeId))` is just
|
||||
`buildCfg` at the tagged payload; `buildCfgL_graph :
|
||||
(buildCfgL t).map (List.map erase) = buildCfg t.erase` connects it to the real
|
||||
CFG; and `GGraph.nodeLabel`/`GGraph.stateOf` read a node's id straight from its
|
||||
payload (`stateOf_label` is the soundness). No `LGraph`, no separate `label`
|
||||
field, no duplicated combinators.
|
||||
|
||||
## ID → CFG-state mapping — totality — DONE
|
||||
|
||||
The `Option`-valued `nodeIdOf`/`stateOfNodeId` are now proven total on the inputs
|
||||
that matter (`Graphs.lean`), via a payload-list characterization of the CFG:
|
||||
|
||||
- `GGraph.nodeList` flattens `nodes` into the list of payloads, with combinator
|
||||
lemmas (`nodeList_comp/link/loop/wrap`) reducing it through the CFG builders.
|
||||
- `Stmt.Tagged.basics` lists a program's basic statements; the master lemma
|
||||
`Stmt.Tagged.cfg_nodeList_filter` (and its program-level
|
||||
`taggedCfg_nodeList_filter`) shows the non-empty CFG nodes are *exactly* the
|
||||
singletons `[bs]` for `bs ∈ basics`.
|
||||
- AST ⇒ CFG: `exists_state_of_mem_basics` (a state with payload `[bs]`) and
|
||||
`stateOfNodeId_isSome` (the search succeeds).
|
||||
- CFG ⇒ AST: `exists_basic_of_code_ne_nil` (a non-empty node is `[bs]`, with
|
||||
`code = [bs.erase]` and `nodeIdOf = some bs.rootTag`) and `nodeIdOf_isSome`.
|
||||
|
||||
All `propext`/`Quot.sound`-only (no `sorry`, no choice).
|
||||
|
||||
Remaining nice-to-have:
|
||||
- Injectivity: distinct basic-statement ids map to distinct states, giving a
|
||||
two-sided id ↔ state correspondence (upgrading the existence results above to a
|
||||
genuine bijection, and pinning `stateOfNodeId (bs.rootTag)` to *the* state
|
||||
holding `bs`). The `tag`-uniqueness fact this needs (`Nodup` of postorder tags)
|
||||
was part of the parked descendant machinery in `DESCENDANT-TRACKING.md`.
|
||||
Reference in New Issue
Block a user