Improved closure context persistence. Now it is possibile to define counters like this func(base){func(){@base=base+1}}

function.go

@@ -21,7 +21,7 @@ func (functor *baseFunctor) ToString(opt FmtOpt) (s string) {
 	if functor.info != nil {
 		s = functor.info.ToString(opt)
 	} else {
-		s = "func() {}"
+		s = "func(){}"
 	}
 	return s
 }
@@ -42,6 +42,10 @@ func (functor *baseFunctor) GetFunc() ExprFunc {
 	return functor.info
 }
 
+func (functor *baseFunctor) GetDefinitionContext() ExprContext {
+	return nil
+}
+
 // ---- Function Parameters
 type paramFlags uint16
 
@@ -94,13 +98,15 @@ func (param *funcParamInfo) DefaultValue() any {
 }
 
 // --- Functions
+
+// funcInfo implements ExprFunc
 type funcInfo struct {
-	name       string
-	minArgs    int
-	maxArgs    int
-	functor    Functor
-	params     []ExprFuncParam
-	returnType string
+	name         string
+	minArgs      int
+	maxArgs      int
+	functor      Functor
+	formalParams []ExprFuncParam
+	returnType   string
 }
 
 func newFuncInfo(name string, functor Functor, returnType string, params []ExprFuncParam) (info *funcInfo, err error) {
@@ -126,7 +132,7 @@ func newFuncInfo(name string, functor Functor, returnType string, params []ExprF
 		}
 	}
 	info = &funcInfo{
-		name: name, minArgs: minArgs, maxArgs: maxArgs, functor: functor, returnType: returnType, params: params,
+		name: name, minArgs: minArgs, maxArgs: maxArgs, functor: functor, returnType: returnType, formalParams: params,
 	}
 	functor.SetFunc(info)
 	return info, nil
@@ -137,7 +143,7 @@ func newUnnamedFuncInfo(functor Functor, returnType string, params []ExprFuncPar
 }
 
 func (info *funcInfo) Params() []ExprFuncParam {
-	return info.params
+	return info.formalParams
 }
 
 func (info *funcInfo) ReturnType() string {
@@ -152,8 +158,8 @@ func (info *funcInfo) ToString(opt FmtOpt) string {
 		sb.WriteString(info.Name())
 	}
 	sb.WriteByte('(')
-	if info.params != nil {
-		for i, p := range info.params {
+	if info.formalParams != nil {
+		for i, p := range info.formalParams {
 			if i > 0 {
 				sb.WriteString(", ")
 			}
@@ -180,7 +186,7 @@ func (info *funcInfo) ToString(opt FmtOpt) string {
 	} else {
 		sb.WriteString(TypeAny)
 	}
-	sb.WriteString(" {}")
+	sb.WriteString("{}")
 	return sb.String()
 }
 
@@ -200,41 +206,52 @@ func (info *funcInfo) Functor() Functor {
 	return info.functor
 }
 
+func (info *funcInfo) AllocContext(parentCtx ExprContext) (ctx ExprContext) {
+	if defCtx := info.functor.GetDefinitionContext(); defCtx != nil {
+		ctx = defCtx.Clone()
+		ctx.SetParent(defCtx)
+	} else {
+		ctx = parentCtx.Clone()
+		ctx.SetParent(parentCtx)
+	}
+	return
+}
+
+func (info *funcInfo) PrepareCall(parentCtx ExprContext, name string, varActualParams *[]any) (ctx ExprContext, err error) {
+	passedCount := len(*varActualParams)
+	if info.MinArgs() > passedCount {
+		err = ErrTooFewParams(name, info.MinArgs(), info.MaxArgs(), passedCount)
+	}
+
+	for i := passedCount; i < len(info.formalParams); i++ {
+		p := info.formalParams[i]
+		if !p.IsDefault() {
+			break
+		}
+		*varActualParams = append(*varActualParams, p.DefaultValue())
+	}
+	if err == nil && info.MaxArgs() >= 0 && info.MaxArgs() < len(*varActualParams) {
+		err = ErrTooMuchParams(name, info.MaxArgs(), len(*varActualParams))
+	}
+
+	if err == nil {
+		ctx = info.AllocContext(parentCtx)
+	}
+	return
+}
+
 // ----- Call a function ---
 
-func checkFunctionCall(ctx ExprContext, name string, varParams *[]any) (err error) {
-	if info, exists, owner := GetFuncInfo(ctx, name); exists {
-		passedCount := len(*varParams)
-		if info.MinArgs() > passedCount {
-			err = ErrTooFewParams(name, info.MinArgs(), info.MaxArgs(), passedCount)
-		}
-		for i, p := range info.Params() {
-			if i >= passedCount {
-				if !p.IsDefault() {
-					break
-				}
-				*varParams = append(*varParams, p.DefaultValue())
-			}
-		}
-		if err == nil && info.MaxArgs() >= 0 && info.MaxArgs() < len(*varParams) {
-			err = ErrTooMuchParams(name, info.MaxArgs(), len(*varParams))
-		}
-		if err == nil && owner != ctx {
-			ctx.RegisterFuncInfo(info)
+func CallFunction(parentCtx ExprContext, name string, actualParams []any) (result any, err error) {
+	if info, exists, _ := GetFuncInfo(parentCtx, name); exists {
+		var ctx ExprContext
+		if ctx, err = info.PrepareCall(parentCtx, name, &actualParams); err == nil {
+			functor := info.Functor()
+			result, err = functor.Invoke(ctx, name, actualParams)
+			exportObjectsToParent(ctx)
 		}
 	} else {
 		err = fmt.Errorf("unknown function %s()", name)
 	}
 	return
 }
-
-func CallFunction(parentCtx ExprContext, name string, params []any) (result any, err error) {
-	ctx := cloneContext(parentCtx)
-	ctx.SetParent(parentCtx)
-
-	if err = checkFunctionCall(ctx, name, &params); err == nil {
-		result, err = ctx.Call(name, params)
-		exportObjectsToParent(ctx)
-	}
-	return
-}