added

vendor/github.com/glycerine/zygomys/zygo/closing.go

@@ -0,0 +1,45 @@
+package zygo
+
+// where we store our closure-supporing stack pointers
+type Closing struct {
+	Stack *Stack
+	Name  string
+	env   *Zlisp
+}
+
+func NewClosing(name string, env *Zlisp) *Closing {
+	stk := env.linearstack.Clone()
+	// be super strict: only store up to our
+	// enclosing function definition, because after
+	// that, the definition time of that function
+	// should be what we use.
+
+	return &Closing{
+		Stack: stk,
+		Name:  name,
+		env:   env}
+}
+
+func NewEmptyClosing(name string, env *Zlisp) *Closing {
+	return &Closing{
+		Stack: env.NewStack(0),
+		Name:  name,
+		env:   env}
+}
+
+func (c *Closing) IsStackElem() {}
+
+func (c *Closing) LookupSymbolUntilFunction(sym *SexpSymbol, setVal *Sexp, maximumFuncToSearch int, checkCaptures bool) (Sexp, error, *Scope) {
+	return c.Stack.LookupSymbolUntilFunction(sym, setVal, maximumFuncToSearch, checkCaptures)
+}
+func (c *Closing) LookupSymbol(sym *SexpSymbol, setVal *Sexp) (Sexp, error, *Scope) {
+	return c.Stack.LookupSymbol(sym, setVal)
+}
+
+func (c *Closing) Show(env *Zlisp, ps *PrintState, label string) (string, error) {
+	return c.Stack.Show(env, ps, label)
+}
+
+func (c *Closing) TopScope() *Scope {
+	return c.Stack.GetTop().(*Scope)
+}