SIP: PTB Type Argument Interpolation

[92GC]

Summary

Extend PTBs so later commands can reference both:

1. types defined by an earlier Publish command; and
2. functions inside the newly published package.

Currently package IDs must be known when the PTB is constructed. This prevents atomic workflows that publish a package,
initialize its assets, and register those assets with existing protocols such as PAS or Govex.

The Problem

const ptb = new Transaction();
const publication = ptb.publish({ modules, dependencies });

// FAILS: cannot call a function in the newly published package.
const [treasuryCap] = ptb.moveCall({
  target: `${???}::my_coin::create_currency`,
  arguments: [coinRegistry],
});

// FAILS: cannot use the newly published type with an existing package.
ptb.moveCall({
  target: `${pasPackage}::policy::new_for_currency`,
  typeArguments: [`${???}::my_coin::MY_COIN`],
  arguments: [namespace, treasuryCap, false],
});

This is particularly relevant to PAS.

PAS creates a policy for an existing currency type:

policy::new_for_currency<C>(
    namespace,
    treasury_cap: &mut TreasuryCap<C>,
    clawback_allowed,
)

A JIT workflow therefore needs to:

1. publish the module defining C;
2. call that module to create and return TreasuryCap<C>;
3. pass C and its TreasuryCap<C> to PAS;
4. register the asset with Govex and create the proposal.

Type-argument interpolation solves step 3, but calling the newly published currency factory also requires target-package
interpolation.

The Solution

const publication = ptb.publish({ modules, dependencies });

const coinType = ptb.typeFromResult(
  publication,
  "my_coin",
  "MY_COIN",
);

const [treasuryCap] = ptb.moveCall({
  target: ptb.targetFromResult(
    publication,
    "my_coin",
    "create_currency",
  ),
  arguments: [coinRegistry],
});

const [policy, policyCap] = ptb.moveCall({
  target: `${pasPackage}::policy::new_for_currency`,
  typeArguments: [coinType],
  arguments: [namespace, treasuryCap, false],
});

ptb.moveCall({
  target: `${govexPackage}::proposal::register_conditional_asset`,
  typeArguments: [coinType],
  arguments: [proposal, treasuryCap, policy],
});

This enables a single PTB to:

• create its currency and TreasuryCap;
• create its PAS policy;
• register it with Govex; and
• create the proposal.