Splat a bunch of modules from elsewhere.

modules/goblins/abstract-types.scm

@@ -0,0 +1,43 @@
+;;; Copyright 2023 Jessica Tallon
+;;;
+;;; Licensed under the Apache License, Version 2.0 (the "License");
+;;; you may not use this file except in compliance with the License.
+;;; You may obtain a copy of the License at
+;;;
+;;;    http://www.apache.org/licenses/LICENSE-2.0
+;;;
+;;; Unless required by applicable law or agreed to in writing, software
+;;; distributed under the License is distributed on an "AS IS" BASIS,
+;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;;; See the License for the specific language governing permissions and
+;;; limitations under the License.
+(define-module (goblins abstract-types)
+  #:export (zilch
+            zilch?
+
+            <tagged>
+            make-tagged
+            make-tagged*
+            tagged?
+            tagged-label
+            tagged-data))
+
+;; This is both a 2nd and secondary "bottom" or null/void type that's used
+;; within CapTP. This works alongside guile's *unspecified* bottom type.
+(define (make-zilch)
+  (define-record-type <zilch>
+    (_make-zilch)
+    zilch?)
+  (values (_make-zilch) zilch?))
+
+(define-values (zilch zilch?)
+  (make-zilch))
+
+(define-record-type <tagged>
+  (make-tagged label data)
+  tagged?
+  (label tagged-label)
+  (data tagged-data))
+
+(define (make-tagged* label . args)
+  (make-tagged label args))