Record types

[aartaka]

#4. Need to define multiple things for each record type:

• Type/conversion/constuctor function name, like Maybe.
• Accessors, like maybe-just, maybe-present.
  • No need for modifier/setters, because LC is immutable.
• Copying-with-modification

[aartaka]

5e06b63 achieves record types, but it basically hard-codes the implementation for record types up to 7. I'm pretty sure there is some smart recursive solution to the "consume N arguments and then apply the last one to the rest" problem...