Draft: Make Case studies work in JIT

[marzipankaiser]

Only for discussion. The case studies are broken for other backends by this, due to stdlib incompatibilities.

[marzipankaiser]

The lexer/parser/anf/pretty case studies now run fine with the newest (few minute old) version of the JIT, with this modified version.

Most notable changes:

• JIT does not have generic infixEq/println, so the necessary overloads are added inline
• Use a "Regex" type that only works with the restricted stuff we need here.
• Some minor changes in how the stdlib works/is used (e.g. don't use mutable arrays)
• Make all toplevel variables lazy/thunked (since machine does not support them)

cc @b-studios

[marzipankaiser]

Problem in ML:

[marzipankaiser]

IIUC, this refers to:

def parseCalls(): Int / Parser =
  or { number(); 1 } {
    var count = 1;
    ident();
    punct("(");
    count = count + parseCalls();
    many {
        punct(",");
        count = count + parseCalls()
    };
    punct(")");
    count
  }

[b-studios]

yes that makes sense, the scope of mutable variable extends over the recursive call. You need to rewrite the example, potentially not using mutable variables

[marzipankaiser]

Ah, thanks - I will try to do so. Afterwards (i.e. when commenting out the above), we will still have this:

Is there a way to make mutually recursive definitions for the ML backend?

[marzipankaiser]

So, Effekt now compiles it to ML when commenting out the parseExpr calls (that still have a "polymorphic recursion" error in or), but then mlton fails with:

sbt:effekt> run --backend ml examples/casestudies/parser.md
[info] running effekt.Server --backend ml examples/casestudies/parser.md
Error: /Users/gaisseml/dev/effekt/effekt/out/examples_casestudies_parser.sml 630.77-637.17.
  Function applied to incorrect argument.
    expects: [(TokenKind_799, string, (int, int, int) Position_794) Token_805]
             -> _
    but got: [unit] -> _
    in: ((member2of2 (NondetDollarcapabil  ...  58 tok_1228))) k2965
[error] java.lang.RuntimeException: Nonzero exit value: 1