> I expect it will be hard to specify a powerful algorithm for filling in the blanks that feels natural to programmers, though. If the compiler frequently compl

> I expect it will be hard to specify a powerful algorithm for filling in the blanks that feels natural to programmers, though. If the compiler frequently complains about missing type information where the programmer doesn’t understand why it complains, the language won’t be popular. This is the problem in a nutshell. Folks in the optional typing and gradual typing communities have been trying to pull this off for decades and so far no one has been able to come up with a language that: 1. Lets you ignore types completely and write dynamically typed code in some parts of the program. 2. Gives you the expected performance of completely typed code in parts of the program that are typed. 3. Is sufficiently pleasant to use that it gets adoption. There are languages that give you either 1 or 2 along with 3. There may be some language out there that gives you 1 and 2 but if so, it doesn't give you 3 or I would have heard of it. I suspect it's intractable.