Add some test-cases for specific typecheck errors
Change avg depth of Arbitrary expr trees & run 10k tests
Previous values sometimes seemed to cause divergence
Update testing Arbitrary insts for updated AST
Fix test-suite for Megaparsec transition
fix tests: Readd Pretty impls for Ast & inst Arbitrary for ConstructorDefs
Move Arbitrary insts to test/Arbitrary.hs
Disallow arbitrary constructors of reserved names like "Fun"
Also increase number of tests
Shrink Arbitrary ASTs for easier debugging. Require more successes.
Add Match, FunMatch, Pat. Lam -> Fun. Use NonEmpty lists. Module Pretty
Wrap ident in newtype, parse defs, parse program
Fix som literal parsing - parse test now passes
Move AST to Ast.hs, add pretty printer, testing w quickcheck + hspec