JetBrains MPS is such an IDE, for a while I was also fascinated by this approach (structured editing) but I now think that the freedom character level editing g

JetBrains MPS is such an IDE, for a while I was also fascinated by this approach (structured editing) but I now think that the freedom character level editing gives is non-negotiable for me it is easier to ask for forgiveness than for permission, the same is true for syntax errors, it is easier to report errors (and fix them) than trying to always maintain a document in a valid state