From b305116d15d9b809ee0601261565cc354cde88bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Mon, 16 Oct 2023 19:03:02 +0200
Subject: Move `false?` to type module.

---
 doc/ref/general/util-type.texi | 12 ++++++++++++
 module/hnh/util/type.scm       |  6 ++++++
 module/vcomponent/base.scm     |  4 +---
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/doc/ref/general/util-type.texi b/doc/ref/general/util-type.texi
index 104b00b3..3a6cba3e 100644
--- a/doc/ref/general/util-type.texi
+++ b/doc/ref/general/util-type.texi
@@ -60,3 +60,15 @@ Useful at the start of procedures.
 Returns the current procedure name as a symbol, or @code{#f} if not found.
 @end defmac
 
+
+@defun false? x
+An alias of @code{not}. Usefull in type predicates when introducing optional
+types, since
+@example
+(or false? integer?)
+@end example
+is much clearer than
+@example
+(or not integer?)
+@end example
+@end defun
diff --git a/module/hnh/util/type.scm b/module/hnh/util/type.scm
index 800834e5..7e1c5a3d 100644
--- a/module/hnh/util/type.scm
+++ b/module/hnh/util/type.scm
@@ -2,6 +2,7 @@
   :use-module ((srfi srfi-1) :select (every))
   :export (build-validator-body
            list-of pair-of
+           false?
            typecheck
            current-procedure-name))
 
@@ -44,3 +45,8 @@
                   (list (quote variable) (quote type-clause) variable)
                   #f)))))
 
+;;; For use in typechecks, since
+;;;   (or false? integer?)
+;;; is much clearer than
+;;;   (or not integer?)
+(define false? not)
diff --git a/module/vcomponent/base.scm b/module/vcomponent/base.scm
index df47a5f5..2a607fc5 100644
--- a/module/vcomponent/base.scm
+++ b/module/vcomponent/base.scm
@@ -3,6 +3,7 @@
   :use-module (srfi srfi-1)
   :use-module (srfi srfi-17)
   :use-module (srfi srfi-88)
+  :use-module ((hnh util type) :select (false?))
   :use-module (hnh util object)
   :use-module (hnh util lens)
   :use-module (hnh util table)
@@ -87,9 +88,6 @@
    (serialize-vcomponent c)
    p))
 
-
-(define false? not)
-
 (define-type (vcomponent printer: print-vcomponent)
   (type                        type: symbol?)
   (vcomponent-children
-- 
cgit v1.2.3