Parser crasher on inline indexable types

[N1ark]

Currently the parser crashes with the following stacktrace when declaring inline indexable types:

$ npx asc assembly/test.ts --target debug
node_modules/assemblyscript/std/portable/index.js:198
    throw new AssertionError(message);
          ^

AssertionError: assertion failed
    at null.Y.assert (node_modules/assemblyscript/std/portable/index.js:198:11)
    at $n.parseExpression (node_modules/assemblyscript/src/parser.ts:4320:18)
    at $n.parseExpressionStart (node_modules/assemblyscript/src/parser.ts:3863:25)
    at $n.parseExpression (node_modules/assemblyscript/src/parser.ts:4113:21)
    at $n.parseExpressionStatement (node_modules/assemblyscript/src/parser.ts:3095:21)
    at $n.parseStatement (node_modules/assemblyscript/src/parser.ts:2977:26)
    at $n.parseBlockStatement (node_modules/assemblyscript/src/parser.ts:3001:28)
    at $n.parseFunctionExpressionCommon (node_modules/assemblyscript/src/parser.ts:1639:21)
    at $n.parseFunctionExpression (node_modules/assemblyscript/src/parser.ts:1595:17)
    at $n.parseExpressionStart (node_modules/assemblyscript/src/parser.ts:3806:31)

Code that crashes the parser:

export const test = () => {
    const x: { [key in u8]: bool } = {};
    return x;
};

Code that doesn't crash the parser (throws an error):

export type Int8Map = { [key in u8]: bool };

export const test = () => {
    const x: Int8Map = {};
    return x;
};

Expected behaviour:
having an inline definition of the type should raise the same error as if it was declared separately

$ npx asc assembly/test.ts  --target debug
ERROR TS1110: Type expected.
    :
 1 │ export type Int8Map = { [key in u8]: bool };
   │                       ~
   └─ in assembly/test.ts(1)

FAILURE 1 parse error(s)

[dcodeIO]

The assertion has been addressed in #2629. Complex types like these cannot currently be parsed, as there isn't really an implementation story for these yet. It would of course be preferable if the parser at least skipped them to then diagnose what exactly is not supported.

[N1ark]

Good to know - thanks ! Closing the issue