moved a subset of source file to the kern package

operator-include.go

@@ -4,6 +4,10 @@
 // operator-include.go
 package expr
 
+import (
+	"git.portale-stac.it/go-pkg/expr/kern"
+)
+
 //-------- include term
 
 func newIncludeTerm(tk *Token) (inst *term) {
@@ -16,7 +20,7 @@ func newIncludeTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalInclude(ctx ExprContext, opTerm *term) (v any, err error) {
+func evalInclude(ctx kern.ExprContext, opTerm *term) (v any, err error) {
 	var childValue any
 
 	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
@@ -24,8 +28,8 @@ func evalInclude(ctx ExprContext, opTerm *term) (v any, err error) {
 	}
 
 	count := 0
-	if IsList(childValue) {
-		list, _ := childValue.(*ListType)
+	if kern.IsList(childValue) {
+		list, _ := childValue.(*kern.ListType)
 		for i, filePathSpec := range *list {
 			if filePath, ok := filePathSpec.(string); ok {
 				if v, err = EvalFile(ctx, filePath); err == nil {
@@ -39,13 +43,13 @@ func evalInclude(ctx ExprContext, opTerm *term) (v any, err error) {
 				break
 			}
 		}
-	} else if IsString(childValue) {
+	} else if kern.IsString(childValue) {
 		filePath, _ := childValue.(string)
 		if v, err = EvalFile(ctx, filePath); err == nil {
 			count++
 		}
 	} else {
-		err = opTerm.errIncompatibleType(childValue)
+		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
 	}
 	if err != nil {
 		//v = count