[GSoC 2016] Updates on external functions

Hello all!

I spent the last week working on tasks related to extending support for more external functions in runtime environment and integrating variables into different sections of ruby_curry.

After implementing free variables and the concept of Narrowing there are a couple of Curry examples which run into an infinite loop during runtime execution (last_1, length_narrow). We identified that this problem was arising due to a design issue in FlatCurry. We are planning to solve this by making changes to ICurry directly in order to bring about minimum changes in ruby_curry.

Apart from this, as mentioned in previous post, the generator table expressions are now bound freshly during runtime instead of compile time. I also worked on moving integers into a separate module CT_Integer which was a long pending task.

The upcoming tasks have been updated in TODO which mainly include new external functions like =:=, cond and solving some issues like support for variables in external functions.