From 124c9536b478415c088c94d700766765b399bc84 Mon Sep 17 00:00:00 2001
From: John Alanbrook <john@pockle.world>
Date: Mon, 23 Feb 2026 19:01:58 -0600
Subject: [PATCH] no more implicit returning in programs and mdouels

---
 audit.ce    |  2 --
 mcode.cm    | 22 +++++++---------------
 vm_suite.ce | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/audit.ce b/audit.ce
index 1dea25d0..45ae149c 100644
--- a/audit.ce
+++ b/audit.ce
@@ -89,5 +89,3 @@ if (length(all_unresolved) > 0) summary = summary + ", " + text(length(all_unres
 log.console(summary)
 }
 run()
-
-$stop()
diff --git a/mcode.cm b/mcode.cm
index d70fa983..073e6691 100644
--- a/mcode.cm
+++ b/mcode.cm
@@ -3103,7 +3103,6 @@ var mcode = function(ast) {
     var local_slot = 0
     var dest = 0
     var statements = ast.statements
-    var last_expr_slot = -1
     var stmt = null
     var kind = null
     var null_slot = 0
@@ -3170,21 +3169,18 @@ var mcode = function(ast) {
       kind = stmt.kind
       if (kind != null) {
         if (kind == "call") {
-          last_expr_slot = gen_expr(stmt.expression, -1)
+          gen_expr(stmt.expression, -1)
         } else if (kind == "return" || kind == "disrupt" ||
-                   kind == "break" || kind == "continue") {
-          gen_statement(stmt)
-          last_expr_slot = -1
-        } else if (kind == "var" || kind == "def" ||
+                   kind == "break" || kind == "continue" ||
+                   kind == "var" || kind == "def" ||
                    kind == "var_list" || kind == "def_list" ||
                    kind == "function" || kind == "block" ||
                    kind == "if" || kind == "while" ||
                    kind == "do" || kind == "for" ||
                    kind == "switch") {
           gen_statement(stmt)
-          last_expr_slot = -1
         } else {
-          last_expr_slot = gen_expr(stmt, -1)
+          gen_expr(stmt, -1)
         }
       } else {
         gen_statement(stmt)
@@ -3192,13 +3188,9 @@ var mcode = function(ast) {
       _i = _i + 1
     }
 
-    if (last_expr_slot >= 0) {
-      emit_1("return", last_expr_slot)
-    } else {
-      null_slot = alloc_slot()
-      emit_1("null", null_slot)
-      emit_1("return", null_slot)
-    }
+    null_slot = alloc_slot()
+    emit_1("null", null_slot)
+    emit_1("return", null_slot)
 
     result = {}
     result.name = filename != null ? filename : "<eval>"
diff --git a/vm_suite.ce b/vm_suite.ce
index 2ac3f651..3581b5de 100644
--- a/vm_suite.ce
+++ b/vm_suite.ce
@@ -7650,6 +7650,59 @@ run("string index in text() call", function() {
   assert_eq(s[0] + sub, "$abc", "reassemble from index + substring")
 })
 
+// ============================================================================
+// NO IMPLICIT RETURN
+// ============================================================================
+
+run("function trailing call no implicit return", function() {
+  var fn = function() { text(42) }
+  assert_eq(fn(), null, "trailing call should not implicitly return")
+})
+
+run("function trailing expression no implicit return", function() {
+  var fn = function() { var x = 1 + 2 }
+  assert_eq(fn(), null, "trailing expression should not implicitly return")
+})
+
+run("function trailing arithmetic no implicit return", function() {
+  var fn = function() {
+    var x = 10
+    x + 5
+  }
+  assert_eq(fn(), null, "bare arithmetic should not implicitly return")
+})
+
+run("function explicit return still works", function() {
+  var fn = function() { return 42 }
+  assert_eq(fn(), 42, "explicit return should work")
+})
+
+run("arrow trailing call no implicit return", function() {
+  var fn = (x) => { text(x) }
+  assert_eq(fn(42), null, "arrow trailing call should not implicitly return")
+})
+
+run("arrow trailing arithmetic no implicit return", function() {
+  var fn = (x) => {
+    var y = x + 1
+    y * 2
+  }
+  assert_eq(fn(5), null, "arrow bare arithmetic should not implicitly return")
+})
+
+run("arrow explicit return still works", function() {
+  var fn = (x) => { return x * 2 }
+  assert_eq(fn(5), 10, "arrow explicit return should work")
+})
+
+run("function explicit return before trailing expr", function() {
+  var fn = function() {
+    return 7
+    text(99)
+  }
+  assert_eq(fn(), 7, "explicit return should take precedence")
+})
+
 // ============================================================================
 // SUMMARY
 // ============================================================================