From 44cc030fb24d69cd2a3e6eb72b7856ae6ee97808 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <eduard@urbach.dev>
Date: Thu, 2 Jul 2026 15:23:49 +0200
Subject: [PATCH] Added an error message for loop control without loops

---
 src/core/compileLoopControl.go             | 5 +++++
 src/core/errors.go                         | 1 +
 src/core/errors_test.go                    | 1 +
 src/core/loopStack.go                      | 6 +++++-
 src/core/testdata/LoopControlWithoutLoop.q | 3 +++
 5 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 src/core/testdata/LoopControlWithoutLoop.q

diff --git a/src/core/compileLoopControl.go b/src/core/compileLoopControl.go
index fca34e9..af750c8 100644
--- a/src/core/compileLoopControl.go
+++ b/src/core/compileLoopControl.go
@@ -19,6 +19,11 @@ func (f *Function) compileLoopControl(control *ast.LoopControl) error {
 	}
 
 	loop := f.loopStack.Current()
+
+	if loop == nil {
+		return errors.New(LoopControlWithoutLoop, f.File, control.Expression.Source())
+	}
+
 	name := call.Children[0].Token.StringFrom(f.File.Bytes)
 
 	switch name {
diff --git a/src/core/errors.go b/src/core/errors.go
index 7a60e91..5882e54 100644
--- a/src/core/errors.go
+++ b/src/core/errors.go
@@ -22,6 +22,7 @@ var (
 	InvalidNumber             = errors.String("Invalid number")
 	InvalidRune               = errors.String("Invalid rune")
 	InvalidStructOperation    = errors.String("Invalid operation on structs")
+	LoopControlWithoutLoop    = errors.String("Loop control without a loop")
 	MissingCommaBetweenFields = errors.String("Missing ',' between struct fields")
 	MissingFieldName          = errors.String("Missing field name")
 	MissingObject             = errors.String("Missing object or identifier")
diff --git a/src/core/errors_test.go b/src/core/errors_test.go
index 8fd0bc5..f01b1df 100644
--- a/src/core/errors_test.go
+++ b/src/core/errors_test.go
@@ -59,6 +59,7 @@ var errs = []struct {
 	{"InvalidLoopHeader.q", core.InvalidLoopHeader},
 	{"InvalidStructOperation.q", core.InvalidStructOperation},
 	{"InvalidStructOperation2.q", core.InvalidStructOperation},
+	{"LoopControlWithoutLoop.q", core.LoopControlWithoutLoop},
 	{"MissingFieldName.q", core.MissingFieldName},
 	{"MissingFieldName2.q", core.MissingFieldName},
 	{"MissingObject.q", core.MissingObject},
diff --git a/src/core/loopStack.go b/src/core/loopStack.go
index e013dd8..10c9228 100644
--- a/src/core/loopStack.go
+++ b/src/core/loopStack.go
@@ -5,8 +5,12 @@ type loopStack struct {
 	loops []*Loop
 }
 
-// Current returns the innermost loop.
+// Current returns the innermost loop or nil if there is none.
 func (s *loopStack) Current() *Loop {
+	if len(s.loops) == 0 {
+		return nil
+	}
+
 	return s.loops[len(s.loops)-1]
 }
 
diff --git a/src/core/testdata/LoopControlWithoutLoop.q b/src/core/testdata/LoopControlWithoutLoop.q
new file mode 100644
index 0000000..52e1ae5
--- /dev/null
+++ b/src/core/testdata/LoopControlWithoutLoop.q
@@ -0,0 +1,3 @@
+main() {
+	loop.stop()
+}
\ No newline at end of file
-- 
2.51.2