Catch beyond index error in browse

go/cache/cache.go

@@ -136,7 +136,6 @@ func(ca *Cache) Reset() {
 func (ca *Cache) Push() error {
 	m := make(map[string]string)
 	ca.Cache = append(ca.Cache, m)
-	//ca.resetCurrent()
 	return nil
 }
 

go/engine/engine.go

@@ -118,8 +118,8 @@ func (en *Engine) Exec(input []byte, ctx context.Context) (bool, error) {
 // - required data inputs to the template are not available.
 // - the template for the given node point is note available for retrieval using the resource.Resource implementer.
 // - the supplied writer fails to process the writes.
-func(en *Engine) WriteResult(w io.Writer) error {
+func(en *Engine) WriteResult(w io.Writer, ctx context.Context) error {
-	r, err := en.vm.Render()
+	r, err := en.vm.Render(ctx)
 	if err != nil {
 		return err
 	}

go/engine/engine_test.go

@@ -82,7 +82,7 @@ func TestEngineInit(t *testing.T) {
 	}
 
 	w := bytes.NewBuffer(nil)
-	err = en.WriteResult(w)
+	err = en.WriteResult(w, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -105,7 +105,7 @@ func TestEngineInit(t *testing.T) {
 		t.Fatalf("expected where-string 'foo', got %s", r)
 	}
 	w = bytes.NewBuffer(nil)
-	err = en.WriteResult(w)
+	err = en.WriteResult(w, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

go/engine/loop.go

@@ -17,7 +17,7 @@ func Loop(en *Engine, startSym string, ctx context.Context, reader io.Reader, wr
 	}
 
 	b := bytes.NewBuffer(nil)
-	en.WriteResult(b)
+	en.WriteResult(b, ctx)
 	fmt.Println(b.String())
 
 	running := true
@@ -37,7 +37,7 @@ func Loop(en *Engine, startSym string, ctx context.Context, reader io.Reader, wr
 			return fmt.Errorf("unexpected termination: %v\n", err)
 		}
 		//b := bytes.NewBuffer(nil)
-		err = en.WriteResult(writer)
+		err = en.WriteResult(writer, ctx)
 		if err != nil {
 			return err
 		}

go/render/menu.go

@@ -4,6 +4,15 @@ import (
 	"fmt"
 )
 
+type BrowseError struct {
+	Idx uint16
+	PageCount uint16
+}
+
+func(err *BrowseError) Error() string {
+	return fmt.Sprintf("index is out of bounds: %v", err.Idx)
+}
+
 // BrowseConfig defines the availability and display parameters for page browsing.
 type BrowseConfig struct {
 	NextAvailable bool
@@ -112,7 +121,8 @@ func(m *Menu) applyPage(idx uint16) error {
 		}
 		return nil
 	} else if idx >= m.pageCount {
-		return fmt.Errorf("index %v out of bounds (%v)", idx, m.pageCount)
+		return &BrowseError{Idx: idx, PageCount: m.pageCount}
+		//return fmt.Errorf("index %v out of bounds (%v)", idx, m.pageCount)
 	}
 	
 	m.reset()

go/render/page.go

@@ -307,20 +307,6 @@ func(pg *Page) render(sym string, values map[string]string, idx uint16) (string,
 			return "", fmt.Errorf("limit exceeded: %v", pg.sizer)
 		}
 	}
-//	s, err = pg.menu.Render(idx)
-//	if err != nil {
-//		return "", err
-//	}
-//	log.Printf("rendered %v bytes for menu", len(s))
-//	if len(s) > 0 {
-//		r += "\n" + s
-//	}
-//	if pg.sizer != nil {
-//		_, ok = pg.sizer.Check(r)
-//		if !ok {
-//			return "", fmt.Errorf("limit exceeded: %v", pg.sizer)
-//		}
-//	}
 	return r, nil
 }
 
@@ -332,12 +318,11 @@ func(pg *Page) Render(sym string, idx uint16) (string, error) {
 		return "", err
 	}
 
-	log.Printf("nosink %v", values)
 	return pg.render(sym, values, idx)
 }
 
 func(pg *Page) Reset() {
 	pg.sink = nil
 	pg.sinkSize = 0
-	//pg.cacheMap = make(map[string]string)
+	pg.cacheMap = make(map[string]string)
 }

go/vm/runner.go

@@ -383,7 +383,7 @@ func(vm *Vm) RunMPrev(b []byte, ctx context.Context) ([]byte, error) {
        return b, nil
 }
 
-func(vm *Vm) Render() (string, error) {
+func(vm *Vm) Render(ctx context.Context) (string, error) {
 	changed, err := vm.st.ResetFlag(state.FLAG_DIRTY)
 	if err != nil {
 		panic(err)	
@@ -393,6 +393,15 @@ func(vm *Vm) Render() (string, error) {
 	}
 	sym, idx := vm.st.Where()
 	r, err := vm.pg.Render(sym, idx)
+	var ok bool
+	_, ok = err.(*render.BrowseError)
+	if ok {
+		vm.Reset()
+		b := NewLine(nil, MOVE, []string{"_catch"}, nil, nil)
+		vm.Run(b, ctx)
+		sym, idx := vm.st.Where()
+		r, err = vm.pg.Render(sym, idx)
+	}
 	if err != nil {
 		return "", err
 	}

go/vm/runner_test.go

@@ -112,16 +112,17 @@ func TestRunLoadRender(t *testing.T) {
 	st.Down("bar")
 
 	var err error
+	ctx := context.TODO()
 	b := NewLine(nil, LOAD, []string{"one"}, []byte{0x0a}, nil)
 	b = NewLine(b, MAP, []string{"one"}, nil, nil)
 	b = NewLine(b, LOAD, []string{"two"}, []byte{0x0a}, nil)
 	b = NewLine(b, MAP, []string{"two"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	b, err = vm.Run(b, context.TODO())
+	b, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
-	r, err := vm.Render()
+	r, err := vm.Render(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -133,17 +134,17 @@ func TestRunLoadRender(t *testing.T) {
 	b = NewLine(nil, LOAD, []string{"two"}, []byte{0x0a}, nil)
 	b = NewLine(b, MAP, []string{"two"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	b, err = vm.Run(b, context.TODO())
+	b, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
 	b = NewLine(nil, MAP, []string{"one"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	_, err = vm.Run(b, context.TODO())
+	_, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
-	r, err = vm.Render()
+	r, err = vm.Render(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -159,11 +160,12 @@ func TestRunMultiple(t *testing.T) {
 	ca := cache.NewCache()
 	vm := NewVm(&st, &rs, ca, nil)
 
+	ctx := context.TODO()
 	b := NewLine(nil, MOVE, []string{"test"}, nil, nil)
 	b = NewLine(b, LOAD, []string{"one"}, []byte{0x00}, nil)
 	b = NewLine(b, LOAD, []string{"two"}, []byte{42}, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	b, err := vm.Run(b, context.TODO())
+	b, err := vm.Run(b, ctx)
 	if err != nil {
 		t.Error(err)
 	}
@@ -179,15 +181,16 @@ func TestRunReload(t *testing.T) {
 	szr := render.NewSizer(128)
 	vm := NewVm(&st, &rs, ca, szr)
 
+	ctx := context.TODO()
 	b := NewLine(nil, MOVE, []string{"root"}, nil, nil)
 	b = NewLine(b, LOAD, []string{"dyn"}, nil, []uint8{0})
 	b = NewLine(b, MAP, []string{"dyn"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	_, err := vm.Run(b, context.TODO())
+	_, err := vm.Run(b, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
-	r, err := vm.Render()
+	r, err := vm.Render(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -197,7 +200,7 @@ func TestRunReload(t *testing.T) {
 	dynVal = "baz"
 	b = NewLine(nil, RELOAD, []string{"dyn"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
-	_, err = vm.Run(b, context.TODO())
+	_, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -310,12 +313,14 @@ func TestRunMenu(t *testing.T) {
 
 	var err error
 
+	ctx := context.TODO()
+
 	b := NewLine(nil, MOVE, []string{"foo"}, nil, nil)
 	b = NewLine(b, MOUT, []string{"0", "one"}, nil, nil)
 	b = NewLine(b, MOUT, []string{"1", "two"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
 
-	b, err = vm.Run(b, context.TODO())
+	b, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Error(err)	
 	}
@@ -324,7 +329,7 @@ func TestRunMenu(t *testing.T) {
 		t.Errorf("expected empty remainder, got length %v: %v", l, b)
 	}
 	
-	r, err := vm.Render()
+	r, err := vm.Render(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -343,12 +348,14 @@ func TestRunMenuBrowse(t *testing.T) {
 
 	var err error
 
+	ctx := context.TODO()
+
 	b := NewLine(nil, MOVE, []string{"foo"}, nil, nil)
 	b = NewLine(b, MOUT, []string{"0", "one"}, nil, nil)
 	b = NewLine(b, MOUT, []string{"1", "two"}, nil, nil)
 	b = NewLine(b, HALT, nil, nil, nil)
 
-	b, err = vm.Run(b, context.TODO())
+	b, err = vm.Run(b, ctx)
 	if err != nil {
 		t.Error(err)	
 	}
@@ -357,7 +364,7 @@ func TestRunMenuBrowse(t *testing.T) {
 		t.Errorf("expected empty remainder, got length %v: %v", l, b)
 	}
 	
-	r, err := vm.Render()
+	r, err := vm.Render(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}