fix syntax-rules macro that manipulate code

CHANGELOG.md

@@ -30,6 +30,7 @@
 * fix Dark Mode colors and scrolling of the page when using Bookmarklet on English Wikipedia
 * remove dependencies on `cond` from `-->` macro so you can use use `-->` inside `cond`
 * fix handling of recursive `flatten` `syntax-rules` macro [#304](https://github.com/jcubic/lips/issues/304)
+* fix macro that manipulate code (see tests/syntax.scm and undswap macro)
 
 ## 1.0.0-beta.18
 ### Breaking

README.md

@@ -8,7 +8,7 @@
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+[![Coverage Status](https://coveralls.io/repos/github/jcubic/lips/badge.svg?branch=devel&9e9d6f8ae74a8a0c59e64c6d8e5b5889)](https://coveralls.io/github/jcubic/lips?branch=devel)
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src/lips.js

@@ -4438,7 +4438,11 @@ function is_env(o) {
 }
 // ----------------------------------------------------------------------
 function is_callable(o) {
-    return is_function(o) || is_continuation(o) || is_parameter(o);
+    return is_function(o) || is_continuation(o) || is_parameter(o) || is_macro(o);
+}
+// ----------------------------------------------------------------------
+function is_macro(o) {
+    return o instanceof Macro || o instanceof SyntaxParameter;
 }
 // ----------------------------------------------------------------------
 function is_promise(o) {

tests/syntax.scm

@@ -1517,3 +1517,16 @@
         (t.is (let-slim (x 10 y 20)
                         (+ x y))
               30)))
+
+(test "syntax: undswap"
+      (lambda (t)
+        ;; ref: https://stackoverflow.com/a/58965190/387194
+        (define-syntax undswap
+          (syntax-rules (_)
+            ((undswap val (e ...))
+             ((undswap val e) ...))
+            ((undswap val _) val)
+            ((undswap val e) e)))
+
+        (t.is (undswap 3 (if _ (+ 3 _ )))
+              6)))