I for one wish that implementations of future languages provide the following features a) Some extension mechanism for the language like clos etc, where hooks are provided for executing code. b) Code walkers c) Documentation about the internals. I dont mind the language implementation being a tad slower because of simplicity but in the core has to be grokkable and extensible by the end programmer.

Existing languages suffice for most easy problems. For the hard problems that ive been tackling lately ive wished I could overcome some logical impedance between what I am doing and the language in a sane way. A few examples where additional flexibility would help a) Opengl is a state machine. Being able to take the graph of my program and write assertions that critical setup functions are called before other GL functions would help detect invalid logical states. b) Before, after functions (which exist in lisp) would be nice. EDIT: c) Being able to say -> for all objects in in my program that match this criteria, do something. Essentially -> for x in criteria(primitives(program)) do foo.

EDIT: A common thread to all the times I feel trapped as a programmer is when I have a knowledge of the meaning of my program which I want to express, or perhaps a question about its existing implementation which I would like answered. Many languages lack the introspective power to help me as a programmer to tackle these situations. Others simply make it inconvenient to do so.