newt/TODO.md

TODO

• Check for shadowing when declaring dcon
• Require infix decl before declaring names
• Allow unicode operators/names
• Web tool
  • edit, view output, view js, run js, monaco would be nice.
  • need to shim out Buffer
• get rid of stray INFO from auto resolution
• handle if_then_else_ style mixfix
• Search should look at context
• records
• copattern matching
• Support @ on the LHS
• Get Combinatory.newt to work
• Remember operators from imports
• Default cases for non-primitives (currently gets expanded to all constructors)
  • This may need a little care. But I think I could collect all constructors that only match wildcards into a single case. This would lose any information from the individual, unnamed cases though.
  • There are cases where we have _ and then Foo on the next line, but they should all get collected into the Foo case. I think I sorted all of this out for primitives.
• Case for primitives
• aoc2023 translation
  • day1
  • day2
  • some "real world" examples
• Maybe Eq and stuff would work for typeclass without dealing with unification issues yet
• unsolved meta errors repeat (need to freeze or only report at end)
• Sanitize JS idents, e.g. _+_
• Generate some programs that do stuff
• import
• consider making meta application implicit in term, so its more readable when printed
  • Currently we have explicit App surrounding Meta when inserting metas. Some people leave that implicit for efficiency. I think it would also make printing more readable.
  • When printing Value, I now print the spine size instead of spine.
• eval for case (see order.newt)
• switch from commit/mustWork to checking progress
• type constructors are no longer generated? And seem to have 0 arity.
• raw let is not yet implemented (although define used by case tree building)
• there is some zero argument application in generated code
• get equality.newt to work
  • broken again because I added J, probably need to constrain scrutinee to value
• inline metas. Maybe zonk after TC/elab
• implicit patterns
• operators
• pair syntax (via comma operator)
• data sugar: data Maybe a = Nothing | Just a
• matching on operators
  • top level
  • case statements
• Lean / Agda ⟨ ⟩
• Lean-like .map, etc? (resolve name in namespace of target type, etc)
• SKIP list syntax
  • Agda doesn't have it, clashes with pair syntax
• autos / typeclass resolution
  • very primitive version in place, not higher order, search at end
  • monad is now working
• do blocks (needs typeclass, overloaded functions, or constrain to IO)
• some solution for + problem (classes? ambiguity?)
• show compiler failure in the editor (exit code != 0)
• write output to file
  • uses -o option
• detect extra clauses in case statements
• add test framework
• decide what to do for erasure
• type at point in vscode
• repl
• LSP
• don't match forced constructors at runtime
  • I think we got this by not switching for single cases
• magic nat (codegen as number with appropriate pattern matching)
• magic tuple? (codegen as array)
• magic newtype? (drop them in codegen)
• vscode: syntax highlighting for String
• add pop or variant of pfunc that maps to an operator, giving the js operator and precedence on RHS

Parsing

• consider allowing σ etc in identifiers
  • Probably need to merge oper / ident first and sort out mixfix in parsing
  • The mixfix parsing can handle this now, need to update lexing.
• Parse error not ideal for \x y z b=> b (points to lambda)

Background

• Read Ulf Norell thesis
• Finish reading dynamic pattern unification paper to see what is missing/wrong with the current implementation

Other issues

• Name space flattening makes it a bit more subtle when a misspelled (or shadowed) constructor turns into a variable.