feat: Introduce an action system and command language

Vectornaut commented

2026-03-19 07:49:20 +00:00

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The branch to be merged introduces actions: trait objects representing things a user can do. It also introduces a command language for describing actions.

One purpose of the action system is to ensure consistency between different user affordances for doing the same thing. On the branch to be merged, as a proof of concept, the element and regulator creation buttons work by creating and executing actions, rather than by acting directly on the application state. A newly introduced keyboard shortcut system provides a different way to trigger each of these actions (addressing issue #132). You can also carry out actions by describing them in the command language and entering those descriptions into the newly introduced command prompt component (addressing issue #133).

The branch to be merged introduces [_actions_](wiki/Action-system): trait objects representing things a user can do. It also introduces a [_command language_](wiki/Command-language) for describing actions. One purpose of the action system is to ensure consistency between different user affordances for doing the same thing. On the branch to be merged, as a proof of concept, the element and regulator creation buttons work by creating and executing actions, rather than by acting directly on the application state. A newly introduced keyboard shortcut system provides a different way to trigger each of these actions (addressing issue #132). You can also carry out actions by describing them in the command language and entering those descriptions into the newly introduced _command prompt_ component (addressing issue #133).

Vectornaut added 16 commits

2026-03-19 07:49:21 +00:00

Start building a command interpreter 526ce3370d

In the process, revamp the element insertion system and turn elements'
identifiers and labels into signals.

This commit moves the responsibility for adding default regulators from
the assembly to the action system, but it the element creation buttons
still work directly on the assembly. This leads to a regression: the
element creation buttons leave out the default regulators.

Introduce action buttons 8cd1c5aed6

Enable interface buttons to trigger actions rather than directly
manipulating the application state.

Reimplement the element and regulator creation buttons as action
buttons. This addresses the regression in the previous commit: the
element creation buttons now produce default regulators again.

This commit introduces a new regression: the button that creates an
inversive distance regulator no longer clears the selection. A reminder
to fix this is added as comment on the `ParametricAction` structure.

Switch from boxed to reference-counted actions 53fa09af43

Unlike boxed actions, reference-counted actions can be cloned, so we can
use them as parameters for parametric actions.

Make subject_array_from_vec less generic a485dd0ee0

This reverts `subject_array_from_vec` to its original form. We made it
more generic to work around difficulties with cloning boxed actions,
but we're not using boxed actions anymore.

Start building a keyboard shortcut system 70010bbb59

Introduce constant actions f2a065737b

Before this commit, the buttons and shortcuts for element creation used
parametric actions where the parameter was always `Ok(())`. With
constant actions, we can make those buttons and shortcuts simpler.

Include names in regulator descriptions 97d8937a31

In the process, introduce a macro to streamline entity naming.

Make actions single-use, with precomputed values c262cce642

Since conditional actions are meant for repeated use, we rebrand them
as "actors".

Only peek at references to precomputed values 3d2c448466

We've gotten away with making `peek` return an owned value so far
because actions' values tend to be lightweight and clonable: often
reference-counted pointers. Conceptually, though, peeking should only
provide a reference, because we expect an action to hold onto its
precomputed value until it's executed.

Enable downcasting of element-valued actions 4dd065309f

Use this to implement the creation of half-curvature regulators.

Resolve regulators created by descendant actions 75d0050b24

Add trailing commas in tests 7957dff2de

Implement point and point coordinate descriptors 2baa3a43af

In the process, unify regulator creation actions.

Explain the proper use and spirit of actions 013a964701

In particular, state the programmer-enforced assumptions that the action
system relies on.

Word the explanation of actions better d055481948

Explain the proper use and spirit of actors

/ test (pull_request) Successful in 3m49s

Details

80d7cf733b

Vectornaut referenced this pull request

2026-03-19 08:00:12 +00:00

Make the command prompt more terminal-like #139

Vectornaut added 1 commit

2026-03-19 21:46:21 +00:00

Move actors to their own module

/ test (pull_request) Failing after 1m41s

Details

dd05799e20

In the process, rename the module providing the `ActorButton` component
to match the component's current name.

Vectornaut commented

2026-03-19 21:50:28 +00:00

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@glen I've moved the Actor trait into its own module, as we discussed during the meeting, so the pull request is ready for review! I think this move is an all-around improvement: it reduces clutter in the action module, and it improves the organization of action and actor imports.

@glen I've moved the `Actor` trait into its own module, as we discussed during the meeting, so the pull request is ready for review! I think this move is an all-around improvement: it reduces clutter in the `action` module, and it improves the organization of action and actor imports.

Vectornaut added 1 commit

2026-03-19 22:17:29 +00:00

Actually check in the new actor module

/ test (pull_request) Successful in 3m42s

Details

8c28db05d2

Vectornaut added 1 commit

2026-03-25 18:05:50 +00:00

Clarify naming of descriptor declaration action

/ test (pull_request) Successful in 3m55s

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8e1d866d29

Vectornaut changed title from ~~feat: Introduce an action system and command language~~ to WIP: feat: Introduce an action system and command language

2026-03-26 04:58:03 +00:00

Vectornaut commented

2026-03-26 05:07:04 +00:00

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I just noticed that regulators created by descendant actions aren't actually being resolved correctly. The command

HalfCurvature Sphere @ 3

doesn't set the regulator of the newly created sphere, because we end up looking for the half-curvature regulator in a clone of the sphere creation action rather than in the original sphere creation action. The cloned sphere creation action creates a different sphere, with a different default half-curvature regulator.

I didn't notice this before because the sphere created by the cloned action has the same curvature has the sphere created by the original action. The command HalfCurvature Sphere therefore prints the expected measurement, even though it's not reading from the expected regulator.

I've put the pull request in draft mode while I work on a fix.

I just noticed that regulators created by descendant actions aren't actually being resolved correctly. The command ``` HalfCurvature Sphere @ 3 ``` doesn't set the regulator of the newly created sphere, because we end up looking for the half-curvature regulator in a clone of the sphere creation action rather than in the original sphere creation action. The cloned sphere creation action creates a different sphere, with a different default half-curvature regulator. I didn't notice this before because the sphere created by the cloned action has the same curvature has the sphere created by the original action. The command `HalfCurvature Sphere` therefore prints the expected measurement, even though it's not reading from the expected regulator. I've put the pull request in draft mode while I work on a fix.

Vectornaut added 1 commit

2026-03-26 06:18:10 +00:00

Use the UnitAction type alias more

/ test (pull_request) Successful in 3m45s

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d316a8f2ed

Vectornaut added 1 commit

2026-03-26 06:25:20 +00:00

Use the Self type more

/ test (pull_request) Successful in 3m42s

Details

50b96be285

Vectornaut commented

2026-03-26 09:21:37 +00:00

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I've drafted a fix for the bug discussed in this comment. The draft includes a strengthened descendant_regulator_resolution_test that's able to catch the bug, using the technique described in the comment.

The fix works by introducing an environment that keeps track of all the elements and regulators that can be referenced within a command. We carry the environment through the whole interpretation process, updating it whenever the thing we're interpreting creates a regulator.

The current implementation of the environment is a little rough around the edges. For example:

It provides parallel "recorded" versions of all the creation command constructors, which take a mutable reference to an environment and record all created regulators in it. This code is pretty repetitive.
It clones the elements_by_id index from the state into the environment for convenience, even though we could've saved a clone by passing the application state and using the elements_by_id index from there.

The implementation is decent enough, though, that I'd feel okay including it in this first pass. Shall I go ahead and push it to the branch to be merged, or would you like to discuss it at a check-in meeting first?

I've drafted a fix for the bug discussed in [this comment](pulls/138#issuecomment-3793). The draft includes a strengthened `descendant_regulator_resolution_test` that's able to catch the bug, using the technique described in the comment. The fix works by introducing an environment that keeps track of all the elements and regulators that can be referenced within a command. We carry the environment through the whole interpretation process, updating it whenever the thing we're interpreting creates a regulator. The current implementation of the environment is a little rough around the edges. For example: - It provides parallel "recorded" versions of all the creation command constructors, which take a mutable reference to an environment and record all created regulators in it. This code is pretty repetitive. - It clones the `elements_by_id` index from the state into the environment for convenience, even though we could've saved a clone by passing the application state and using the `elements_by_id` index from there. The implementation is decent enough, though, that I'd feel okay including it in this first pass. Shall I go ahead and push it to the branch to be merged, or would you like to discuss it at a check-in meeting first?

glen commented

2026-03-28 10:02:27 +00:00

Owner

@Vectornaut wrote in #138 (comment):

Shall I go ahead and push it to the branch to be merged,

Yes, I am keen to move this along and in to the main branch. Thanks!

@Vectornaut wrote in https://code.studioinfinity.org/StudioInfinity/dyna3/pulls/138#issuecomment-3796: > Shall I go ahead and push it to the branch to be merged, Yes, I am keen to move this along and in to the main branch. Thanks!

Vectornaut added 5 commits

2026-03-31 07:35:05 +00:00

Use an environment to keep track of regulators abd1a51f1f

This replaces the old system where regulator information was stored
throughout the action tree, and fixes a bug that the old system made
difficult to address. We modify `descendant_regulator_resolution_test`
to catch the bug.

Improve the names of the recording constructors f73ee6460f

Drop old code ba0e0060da

Allow statements within larger syntax trees 14053294e1

Rename descriptor statements as declarations

/ test (pull_request) Successful in 3m43s

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4c9ddff53a

Vectornaut changed title from ~~WIP: feat: Introduce an action system and command language~~ to feat: Introduce an action system and command language

2026-03-31 07:40:24 +00:00

Vectornaut commented

2026-03-31 07:46:27 +00:00

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Okay, I've pushed the fix and reactivated the pull request! Commit 1405329 does a reorganization that I'm finding helpful for implementing the "details" or "attributes" syntax we'll use to avoid repetition in the engine block and elsewhere in our save files.

Okay, I've pushed the fix and reactivated the pull request! Commit 1405329 does a reorganization that I'm finding helpful for implementing the "details" or "attributes" syntax we'll use to avoid repetition in the engine block and elsewhere in our save files.

/ test (pull_request) Successful in 3m43s

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