From 4e923ed30b7a48b7e5aa6ce4eadff1ff96904c20 Mon Sep 17 00:00:00 2001
From: Patrick Ferris <patrick@sirref.org>
Date: Fri, 23 Jan 2026 13:20:57 +0000
Subject: [PATCH] Until compound commands

---
 src/lib/eval.ml | 15 +++++++++++----
 test/while.t    | 25 +++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/lib/eval.ml b/src/lib/eval.ml
index 467a1c8..e81e3c7 100644
--- a/src/lib/eval.ml
+++ b/src/lib/eval.ml
@@ -778,6 +778,16 @@ module Make (S : Types.State) (E : Types.Exec) = struct
     in
     loop (Exit.zero ctx)
 
+  and handle_until_clause ctx
+      (Until ((term, sep), (term', sep')) : Ast.until_clause) =
+    let rec loop exit_so_far =
+      let running_ctx = Exit.value exit_so_far in
+      match exec running_ctx (term, Some sep) with
+      | Exit.Zero _ -> exit_so_far (* TODO: Context? *)
+      | Exit.Nonzero { value = ctx; _ } -> loop (exec ctx (term', Some sep'))
+    in
+    loop (Exit.zero ctx)
+
   and handle_compound_command ctx v : ctx Exit.t =
     match v with
     | Ast.ForClause fc -> handle_for_clause ctx fc
@@ -786,10 +796,7 @@ module Make (S : Types.State) (E : Types.Exec) = struct
     | Ast.Subshell s -> exec_subshell ctx s
     | Ast.CaseClause cases -> handle_case_clause ctx cases
     | Ast.WhileClause while_ -> handle_while_clause ctx while_
-    | _ as c ->
-        Fmt.epr "Compound command not supported: %a\n%!" yojson_pp
-          (Ast.compound_command_to_yojson c);
-        exit 127
+    | Ast.UntilClause until -> handle_until_clause ctx until
 
   and handle_function_application (ctx : ctx) ~name argv : ctx Exit.t option =
     match List.assoc_opt name ctx.functions with
diff --git a/test/while.t b/test/while.t
index 6271dbd..ba4fb72 100644
--- a/test/while.t
+++ b/test/while.t
@@ -23,3 +23,28 @@ While clauses.
   Iteration 3...
   Iteration 4...
   Iteration 5...
+
+Also until loops.
+
+  $ cat > test.sh << EOF
+  > i=1
+  > 
+  > until [ "\$i" -ge 5 ]
+  > do
+  >   echo "Iteration \$i..."
+  >   i=\$((i + 1))
+  > done
+  > 
+  > EOF
+
+
+  $ sh test.sh
+  Iteration 1...
+  Iteration 2...
+  Iteration 3...
+  Iteration 4...
+  $ msh test.sh
+  Iteration 1...
+  Iteration 2...
+  Iteration 3...
+  Iteration 4...
-- 
2.51.2