From a04cc1732c4b73da13e8a7ffd1042262a0577e8a Mon Sep 17 00:00:00 2001
From: Gergo Magyar <gergomagyar@icloud.com>
Date: Mon, 20 Apr 2026 12:01:03 +0100
Subject: [PATCH] feat(python-scope): enumerate(X) for-loop tuple destructuring
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Adds two new typeBinding capture patterns for the canonical enumerate
pattern:

  for (i, u) in enumerate(users): ...   ; tuple_pattern
  for  i, u  in enumerate(users): ...   ; pattern_list

Both bind the second tuple element (u) to the iterable identifier
(users). The chain-follow then unwraps users → its element type via
the existing generic-strip in interpret.ts (List[User] → User).

The #eq? predicate scopes the pattern to enumerate specifically;
generic tuple destructuring of arbitrary callables is left to a
future iteration once we have a richer signal for "what does this
call yield".

Verification:
- Flag-off: 191/191 (identical baseline).
- Flag-on: 7 fail / 184 pass (was 8/183; +1 — `parenthesized tuple:
  for (i, u) in enumerate(users)` now passes).
- tsc --noEmit clean.
---
 .../core/ingestion/languages/python/query.ts  | 25 +++++++++++++++++++
 .../ingestion/languages/python/scopes.scm     | 24 ++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/gitnexus/src/core/ingestion/languages/python/query.ts b/gitnexus/src/core/ingestion/languages/python/query.ts
index 4732340cc..87f2eee39 100644
--- a/gitnexus/src/core/ingestion/languages/python/query.ts
+++ b/gitnexus/src/core/ingestion/languages/python/query.ts
@@ -119,6 +119,31 @@ export const PYTHON_SCOPE_QUERY = `
   right: (call
     function: (identifier) @type-binding.type)) @type-binding.alias
 
+;; for (i, u) in enumerate(X) — paren-tuple, bind last element to X's
+;; element type. \`enumerate(X)\` yields (int, X-element); the second
+;; pattern var takes X (which the chain-follow then unwraps to its
+;; element type via generic-strip in interpret.ts).
+(for_statement
+  left: (tuple_pattern
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
+;; for i, u in enumerate(X) — pattern_list (no parens) variant.
+(for_statement
+  left: (pattern_list
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
 ;; Type bindings (variable annotations: \`u: User\` / \`u: User = x\`)
 (assignment
   left: (identifier) @type-binding.name
diff --git a/gitnexus/src/core/ingestion/languages/python/scopes.scm b/gitnexus/src/core/ingestion/languages/python/scopes.scm
index 69ca6c59c..944cab3d6 100644
--- a/gitnexus/src/core/ingestion/languages/python/scopes.scm
+++ b/gitnexus/src/core/ingestion/languages/python/scopes.scm
@@ -134,6 +134,30 @@
   right: (call
     function: (identifier) @type-binding.type)) @type-binding.alias
 
+; for (i, u) in enumerate(X) and for i, u in enumerate(X) — bind the
+; second tuple element to X. enumerate yields (int, X-element); the
+; chain-follow unwraps X via generic-strip when X is an annotated
+; collection.
+(for_statement
+  left: (tuple_pattern
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
+(for_statement
+  left: (pattern_list
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
 ; ─── Type bindings: function return-type annotations ─────────────────────
 ;
 ; `def get_user() -> User:` — binds the function's NAME to its return