From 262e553d94c4124bdb53784e73dd314e3e44f3b8 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Wed, 13 Apr 2022 19:49:33 -0700
Subject: Some egawk support: use @let in case if available.

---
 cppawk                     | 3 +++
 cppawk-include/base.h      | 9 ++++++++-
 cppawk-include/case-priv.h | 8 +++++++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/cppawk b/cppawk
index 265d293..9af2138 100755
--- a/cppawk
+++ b/cppawk
@@ -134,6 +134,9 @@ while [ $# -gt 0 ] ; do
       gawk | mawk | */gawk | */mawk )
         prepro_opts="$prepro_opts -U__gawk__ -D__$(basename "$awk")__=1"
         ;;
+      egawk | */egawk )
+        prepro_opts="$prepro_opts -D__egawk__=1"
+        ;;
     esac
     ;;
   --nobash )
diff --git a/cppawk-include/base.h b/cppawk-include/base.h
index 5472233..568ffcd 100644
--- a/cppawk-include/base.h
+++ b/cppawk-include/base.h
@@ -42,9 +42,16 @@
 
 #define __present(arg) ((arg) != "" || (arg) != 0)
 
+#if __egawk__
+#define __let(...) @let (__VA_ARGS__)
+#define __have_let 1
+#else
+#define __let(...)
+#endif
+
 #if __gawk__
 #define __have_switch 1
-#if __gawk_ver >= 040000
+#if __gawk_ver >= 040000 || __egawk__
 #define __have_indirect_functions 1
 #endif
 #endif
diff --git a/cppawk-include/case-priv.h b/cppawk-include/case-priv.h
index 6421877..3676e2b 100644
--- a/cppawk-include/case-priv.h
+++ b/cppawk-include/case-priv.h
@@ -64,8 +64,14 @@
 #define __mtch_next(p,                                                        \
                     x)  p || (__val ~ (x))
 
+#if !__have_let
 #define __case_temps    __val, __once, __pass
-#define __case(expr)    for ((__once = 1) && (__pass = 0) || (__val = expr);  \
+#else
+#define __case_temps    __ign
+#endif
+
+#define __case(expr)    __let (__val, __once, __pass)                         \
+                        for ((__once = 1) && (__pass = 0) || (__val = expr);  \
                              __once;                                          \
                              __once = 0)
 #define __of(...)       __clause(__varexpand(__of_first, __of_next,           \
-- 
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