1 files changed, 17 insertions, 0 deletions
diff --git a/shell/macroexpand.mu b/shell/macroexpand.mu
index 018fa200..047d4dfd 100644
--- a/shell/macroexpand.mu
+++ b/shell/macroexpand.mu
@@ -1,3 +1,20 @@
 fn macroexpand _in-ah: (addr handle cell), _out-ah: (addr handle cell), globals: (addr global-table), trace: (addr trace) {
+  var in-ah/esi: (addr handle cell) <- copy _in-ah
+  var out-ah/edi: (addr handle cell) <- copy _out-ah
+  # loop until convergence
+  {
+    macroexpand-iter in-ah, out-ah, globals, trace
+    var _in/eax: (addr cell) <- lookup *in-ah
+    var in/ecx: (addr cell) <- copy _in
+    var out/eax: (addr cell) <- lookup *out-ah
+    var done?/eax: boolean <- cell-isomorphic? in, out, trace
+    compare done?, 0/false
+    break-if-!=
+    copy-object out-ah, in-ah
+    loop
+  }
+}
+
+fn macroexpand-iter _in-ah: (addr handle cell), _out-ah: (addr handle cell), globals: (addr global-table), trace: (addr trace) {
   copy-object _in-ah, _out-ah
 }