Syntax-directed editors were all the rage in the late 70s early 80s...and a huge failure, because they were a lot more annoying than any text editor has a chance of ever being.

It's one of those things that, like visual programming, is absolutely and obviously The Right Thing™ until you try to implement it and use it.

That said, we have made progress in both areas, and maybe we will figure them out in the future.