New generics: a static class sees the enclosing class's parameter as its own variable

[Frotty]

Stacked on #1423 (base generic-interface-bridge). Merge this one into #1423's branch before #1423 is merged, or a roll-up PR to master follows.

Problem

A static class inside a generic class (class Outer<T:> with static class Holder) gets a type variable of its own for T. The translator did not use it consistently. Lua accepted these programs, but Jass failed to compile them:

• Members of the static class. A member was translated with the type variables of whichever code asked for it first. A method that Outer calls took and returned Outer's T, while its body used the static class's own variable. The error was Type variable T not eliminated. Fields, constructors, ondestroy blocks and closures failed the same way.
• Types of the static class. A type of the static class had no argument for that variable, so C extends Base gave C the superclass Base<>. The error was Rewrite generics with wrong sizes. The same happened with or without an interface. This is why Interface bridge: give generic classes a method of their own too #1423's static-class test ran on Lua only.
• Static functions of the static class. Such a function is not in its class, but it used the class's variable, which it does not have.

Change

Members. A class's members (methods, constructors, ondestroy, fields) are now translated with the class's own type variables, whichever code asks for them first. In a static class, these include the captured variable. The type of this is the class with its own variables, and the class's variables no longer depend on where it is first used.

Types. A type of a static class carries an argument for its captured variable. The argument is one of two things:

• what the type binds it to: new Outer<int>().make() returns a Base with T bound to int;
• otherwise, the parameter as the surrounding code sees it: Outer's own variable inside Outer, and the captured one inside the static class.

This means C extends Base now gives C the superclass Base<T_C>. Super constructor and ondestroy calls pass the argument along.

Static functions. A static function of a static class takes the captured parameter as a type variable of its own, as a static function of the generic class already does.

Removed patch. EliminateGenerics no longer fills in missing class type arguments by matching type-variable names. Nothing produces the short types any more.

Interface bridge (#1423). typeArgumentsAsSeenFrom now translates the superclass's type as the class's own functions do, with the class's type variables. A static class that implements an interface through an inherited method over T is now dispatched on Jass too.

Checks

• New tests: nine GenericsWithTypeclassesTests and one InterfaceTests case, each running Jass, the interpreter and Lua. They cover:

  • a method, a field, a constructor with ondestroy, and a closure, each over T;
  • a generic static class using its own parameter and T;
  • static functions of a static class;
  • a static class extending a plain or a generic sibling;
  • overrides between sibling static classes.

  All of them failed on Interface bridge: give generic classes a method of their own too #1423's head (Jass), as did Interface bridge: give generic classes a method of their own too #1423's static-class test, which now runs on Jass too.

• Determinism: a new DeterministicChecks case puts the interface in its own package and compiles in both unit orders. The Jass and Lua are identical.

• Test classes: these 23 pass (1,407 tests): the 23 classes Interface bridge: give generic classes a method of their own too #1423 lists, including GenericsWithTypeclassesTests, GenericsTests, ClassesTests, InterfaceTests, DeterministicChecks and BugTests.

• Real maps: castle fight and zombie defense, built with -lua -inline -localOptimizations, produce Lua byte-identical to Interface bridge: give generic classes a method of their own too #1423's head.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-09T21:49:59.560567Z	82cbee1	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.