diff --git a/common-params.go b/common-params.go
index d86f519..2eb0bf5 100644
--- a/common-params.go
+++ b/common-params.go
@@ -16,15 +16,6 @@ const (
 	paramEnd       = "end"
 	paramValue     = "value"
 	paramEllipsis  = "..."
-	typeFilepath   = "filepath"
-	typeDirpath    = "dirpath"
+	paramFilepath  = "filepath"
+	paramDirpath   = "dirpath"
 )
-
-// const (
-// 	typeInteger  = "int"
-// 	typeFloat    = "float"
-// 	typeString   = "string"
-// 	typeFraction = "fract"
-// 	typeList     = "list"
-// 	typeDict     = "dict"
-// )
diff --git a/func-os.go b/func-os.go
index bf433d6..763aba3 100644
--- a/func-os.go
+++ b/func-os.go
@@ -188,13 +188,13 @@ func readFileFunc(ctx ExprContext, name string, args []any) (result any, err err
 
 func ImportOsFuncs(ctx ExprContext) {
 	ctx.RegisterFunc("openFile", newGolangFunctor(openFileFunc), typeHandle, []ExprFuncParam{
-		newFuncParam(typeFilepath),
+		newFuncParam(paramFilepath),
 	})
 	ctx.RegisterFunc("appendFile", newGolangFunctor(appendFileFunc), typeHandle, []ExprFuncParam{
-		newFuncParam(typeFilepath),
+		newFuncParam(paramFilepath),
 	})
 	ctx.RegisterFunc("createFile", newGolangFunctor(createFileFunc), typeHandle, []ExprFuncParam{
-		newFuncParam(typeFilepath),
+		newFuncParam(paramFilepath),
 	})
 	ctx.RegisterFunc("writeFile", newGolangFunctor(writeFileFunc), typeInt, []ExprFuncParam{
 		newFuncParam(typeHandle),