Address code review feedback

Export binding-site-identifiers and use it directly in variable-mutability-analyzer to avoid redundant initialization loop. Add documentation to fully-expanded-syntax-id-table.

Co-authored-by: jackfirth <[email protected]>

Author: Copilot

default-recommendations/analyzers/private/expanded-id-table.rkt

@@ -17,6 +17,7 @@
   [in-expanded-id-table-phase
    (-> expanded-id-table? (or/c exact-nonnegative-integer? #false) (sequence/c (entry/c expanded-identifier? any/c)))]
   [syntax-label-id-phases (-> syntax? syntax?)]
+  [binding-site-identifiers (-> syntax? stream?)]
   [fully-expanded-syntax-id-table (-> syntax? expanded-id-table?)]))
 
 
@@ -153,6 +154,10 @@
               (map recur (append* (attribute body))))])))
 
 
+;; Builds an expanded-id-table from phase-labeled syntax.
+;; The input syntax should already have phase labels added via syntax-label-id-phases.
+;; Returns an expanded-id-table mapping expanded-identifiers to empty lists,
+;; with one entry for each binding site in the syntax.
 (define (fully-expanded-syntax-id-table stx)
   ;; stx is expected to already have phase labels via syntax-label-id-phases
   (define table (make-expanded-id-table))

default-recommendations/analyzers/variable-mutability.rkt

@@ -47,12 +47,11 @@
 (define (variable-mutability stx)
   (define labeled-stx (syntax-label-id-phases (syntax-label-paths stx 'expanded-path)))
 
-  ;; Create table with all bound identifiers initialized to 'immutable
-  (define variable-table (fully-expanded-syntax-id-table labeled-stx))
-  
-  ;; Initialize all entries with 'immutable
-  (for ([entry (in-expanded-id-table variable-table)])
-    (expanded-id-table-set! variable-table (entry-key entry) 'immutable))
+  ;; Create table and initialize all bound identifiers with 'immutable
+  (define variable-table (make-expanded-id-table))
+  (for ([id (in-stream (binding-site-identifiers labeled-stx))])
+    (define phase (syntax-property id 'phase))
+    (expanded-id-table-set! variable-table (expanded-identifier id phase) 'immutable))
 
   ;; Mark mutated variables as 'mutable
   (for ([id (in-stream (mutated-variables labeled-stx))])