Syntax Checker

I need to create in my application a component like a TextArea which validate data introduced by the user (against a custom syntax) and suggest completion.
In this component every character intoduced by the user will produce a check of the correct syntax and, if needed, will suggest something.
Is there such component ?
If not, as I suspect, is better to create an extension for the TextArea component or create a brand new component.
All suggestions are welcome.