From ead347128aab822ed90593627db8f7012b980a05 Mon Sep 17 00:00:00 2001
From: Timothy Sample <samplet@ngyro.com>
Date: Thu, 28 Apr 2022 09:58:59 -0600
Subject: [PATCH] compat: Support Mes.

* gash/compat.scm (if-guile-version-below) [mes]: Do nothing.
(when-mes): New syntax.
* .dir-locals.el: Tell Emacs how to indent it.
---
 .dir-locals.el  |  1 +
 gash/compat.scm | 59 ++++++++++++++++++++++++++++---------------------
 2 files changed, 35 insertions(+), 25 deletions(-)

diff --git a/.dir-locals.el b/.dir-locals.el
index b400e62..b5b3921 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -7,6 +7,7 @@
                                                   ".dir-locals.el")))
                  (add-to-list 'geiser-guile-load-path top))))
      (eval . (put 'if-guile-version-below 'scheme-indent-function 1))
+     (eval . (put 'when-mes 'scheme-indent-function 0))
      (eval . (put '<sh-case> 'scheme-indent-function 1))
      (eval . (put '<sh-defun> 'scheme-indent-function 1))
      (eval . (put '<sh-exec-let> 'scheme-indent-function 1))
diff --git a/gash/compat.scm b/gash/compat.scm
index e98c7df..47a7abd 100644
--- a/gash/compat.scm
+++ b/gash/compat.scm
@@ -1,5 +1,5 @@
 ;;; Gash -- Guile As SHell
-;;; Copyright © 2019 Timothy Sample <samplet@ngyro.com>
+;;; Copyright © 2019, 2022 Timothy Sample <samplet@ngyro.com>
 ;;;
 ;;; This file is part of Gash.
 ;;;
@@ -18,7 +18,8 @@
 
 (define-module (gash compat)
   #:use-module (ice-9 match)
-  #:export (if-guile-version-below))
+  #:export (if-guile-version-below
+            when-mes))
 
 ;;; Commentary:
 ;;;
@@ -27,30 +28,38 @@
 ;;;
 ;;; Code:
 
-(define-syntax if-guile-version-below
-  (lambda (x)
-    (define (guile-version<? major minor micro)
-      (let ((g-major (string->number (major-version)))
-            (g-minor (string->number (minor-version)))
-            (g-micro (string->number (micro-version))))
-        (or (< g-major major)
-            (and (= g-major major)
-                 (< g-minor minor))
-            (and (= g-major major)
-                 (= g-minor minor)
-                 (< g-micro micro)))))
+(cond-expand
+ (guile
+  (define-syntax if-guile-version-below
+    (lambda (x)
+      (define (guile-version<? major minor micro)
+        (let ((g-major (string->number (major-version)))
+              (g-minor (string->number (minor-version)))
+              (g-micro (string->number (micro-version))))
+          (or (< g-major major)
+              (and (= g-major major)
+                   (< g-minor minor))
+              (and (= g-major major)
+                   (= g-minor minor)
+                   (< g-micro micro)))))
 
-    (syntax-case x ()
-      ((_ (maj min mic) consequent alternate)
-       (if (guile-version<? (syntax->datum #'maj)
-                            (syntax->datum #'min)
-                            (syntax->datum #'mic))
-           #'consequent
-           #'alternate))
-      ((_ (maj min mic) consequent)
-       #'(if-guile-version-below (maj min mic)
-           consequent
-           (if #f #t))))))
+      (syntax-case x ()
+        ((_ (maj min mic) consequent alternate)
+         (if (guile-version<? (syntax->datum #'maj)
+                              (syntax->datum #'min)
+                              (syntax->datum #'mic))
+             #'consequent
+             #'alternate))
+        ((_ (maj min mic) consequent)
+         #'(if-guile-version-below (maj min mic)
+             consequent
+             (if #f #t))))))
+  (define-syntax-rule (when-mes . forms) (if #f #t)))
+ (mes
+  (define-macro (if-guile-version-below . forms)
+    '(begin))
+  (define-macro (when-mes . forms)
+    `(begin ,@forms))))
 
 (if-guile-version-below (2 0 10)
   (begin