[ 210_11] 给hash-table补上hash-table-fold函数

Author: 17802723

devel/210_11.md

@@ -0,0 +1,3 @@
+# 210_11
+
+## 2026/01/30 为hash-table补上hash-table-fold函数

goldfish/liii/hash-table.scm

@@ -25,11 +25,10 @@
     hash-table-set! hash-table-delete! hash-table-intern! hash-table-update!
     hash-table-update!/default hash-table-pop! hash-table-clear!
     hash-table-size hash-table-keys hash-table-values hash-table-entries
-    hash-table-find hash-table-count
+    hash-table-find hash-table-count hash-table-fold
     hash-table-for-each hash-table-map->list
     hash-table->alist
     )
   (begin
     ) ; end of begin
   ) ; end of library
-

goldfish/srfi/srfi-125.scm

@@ -21,7 +21,8 @@
           hash-table-ref/default hash-table-set! hash-table-delete! hash-table-intern!
           hash-table-update! hash-table-update!/default hash-table-pop! hash-table-clear!
           hash-table-size hash-table-keys hash-table-values hash-table-entries hash-table-find
-          hash-table-count hash-table-for-each hash-table-map->list hash-table->alist)
+          hash-table-count hash-table-fold hash-table-for-each hash-table-map->list
+          hash-table->alist)
   (begin
 
     (define (assert-hash-table-type ht f)
@@ -128,6 +129,15 @@
       (typed-lambda ((pred? procedure?) (ht hash-table?))
         (count (lambda (x) (pred? (car x) (cdr x))) (map values ht))))
 
+    (define (hash-table-fold proc seed ht)
+      (assert-hash-table-type ht hash-table-fold)
+      (let ((result seed))
+        (hash-table-for-each
+         (lambda (k v)
+           (set! result (proc k v result)))
+         ht)
+        result))
+
     (define hash-table-for-each
       (typed-lambda ((proc procedure?) (ht hash-table?))
         (for-each (lambda (x) (proc (car x) (cdr x))) ht)))

tests/goldfish/liii/hash-table-test.scm

@@ -256,6 +256,12 @@
     (hash-table 'a 1 'b 2 'c 3))
   (check cnt => 6))
 
+(let ((ht (hash-table 'a 1 'b 2 'c 3)))
+  (check (hash-table-fold (lambda (k v acc) (+ acc v)) 0 ht) => 6)
+  )
+
+(check (hash-table-fold (lambda (k v acc) (+ acc v)) 10 (hash-table)) => 10)
+
 (let* ((ht (hash-table 'a 1 'b 2 'c 3))
        (ks (hash-table-map->list (lambda (k v) k) ht))
        (vs (hash-table-map->list (lambda (k v) v) ht)))
@@ -275,4 +281,3 @@
        => (list 'k1 'v1))
 
 (check-report)
-