1 files changed, 66 insertions, 0 deletions
diff --git a/pypi/sdist-store/dependency-sets.scm b/pypi/sdist-store/dependency-sets.scm
new file mode 100644
index 0000000..d8fb920
--- /dev/null
+++ b/pypi/sdist-store/dependency-sets.scm
@@ -0,0 +1,66 @@
+(define-module (pypi sdist-store dependency-sets)
+  #:use-module (srfi srfi-9)
+  #:use-module (ice-9 vlist)
+  #:export (make-dependency-sets-record
+            add-dependency-set
+            remove-dependency-set
+            dependency-sets->list
+            get-dependency-set-keys-matching
+            get-dependency-set-keys
+            get-dependency-set))
+
+(define-record-type <dependency-sets>
+  (new-dependency-sets-record vhash next-key)
+  dependency-sets-record?
+  (vhash    dependency-sets-vhash)
+  (next-key      dependency-sets-next-key))
+
+(define (make-dependency-sets-record)
+  (new-dependency-sets-record
+    vlist-null
+    0))
+
+(define (add-dependency-set dependency-sets entry)
+  (let ((key (dependency-sets-next-key dependency-sets)))
+    (new-dependency-sets-record
+      (vhash-consq
+        key
+        entry
+        (dependency-sets-vhash dependency-sets))
+      (+ key 1))))
+
+(define (remove-dependency-set dependency-sets key)
+  (new-dependency-sets-record
+    (vhash-delq
+      key
+      (dependency-sets-vhash dependency-sets))
+    (dependency-sets-next-key dependency-sets)))
+
+(define (dependency-sets->list proc dependency-sets)
+  (vhash-fold
+    (lambda (key value result)
+      (cons
+        (proc key value)
+        result))
+    '()
+    (dependency-sets-vhash dependency-sets)))
+
+(define (get-dependency-set-keys-matching dependency-sets proc)
+  (vhash-fold
+    (lambda (key value result)
+      (if (proc value)
+        (cons key result)
+        result))
+    '()
+    (dependency-sets-vhash dependency-sets)))
+
+(define (get-dependency-set-keys dependency-sets)
+  (vhash-fold
+    (lambda (key value result)
+      (cons key result))
+    '()
+    (dependency-sets-vhash dependency-sets)))
+
+(define (get-dependency-set dependency-sets key)
+  (cdr
+    (vhash-assq key (dependency-sets-vhash dependency-sets))))