Add capability to pin a main file

[Myriad-Dreamin]

This PR proposes an abstraction corresponding to "Preview this file" in official webapp. In conclusion, this PR adds a "typst-lsp.doPinMain" command to lsp program which could then get used by:

• user manually runs command "typst-lsp.pinMainToCurrent" or "typst-lsp.unpinMain" in VSCode.
• user writes some lua script to automate the pin action.
• some other vscode extension (such as typst-preview) pins a previewing file automatically.

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Usage 1: improve mode of exportPDF by adding "onPinnedMain{Save,Type}".
Currently, automatically exportPDF on save or on type is annoying since typst-lsp cannot identify the source files that has empty content. This PR can allow users only exporting PDF "onPinnedMain{Save,Type}", close #11, may close #184, may close #285.

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Usage 2: make hover tip and autocompletion according to the pinned file.

Before, hover variable in template.typ doesn't work at all:

After, it shows result correctly:

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Usage 3: show diagnostics according to compilation of the pinned file when editing other files, close #153.

Before, the errors in thesis.typ fly away if the user doesn't focus thesis.typ:

After, lsp will show diagnostics according to compilation of the pinned file when editing template.typ:

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Usage 3.5: eliminate false errors in a project with multiple files.

Note that lsp may also produces false errors, such as errors on bib things. Once this PR is ready, editors could pin the main file in a project with multiple files, may close #64, may close #366.

[PgBiel]

Great work! I wonder, is there a way to add a context menu button to .typ files so that you can right-click them and select "Pin file" or something? That would be interesting... (But also not strictly necessary for this PR)

[Myriad-Dreamin]

@PgBiel I think this abstraction is mostly used by editor scripts. Therefore, you don't have to pin them manually, but with some configuration on your favorite editor. For example, I made a branch in typst-preview, which invokes "typst-lsp.pinMainToCurrent" when it starts to preview some file, https://github.com/Enter-tainer/typst-preview/tree/pin-lsp. There is also a configurable switch to enable/disable it, determined by users. I believe neovim users may invent other luascript like it.

Your idea also looks great to me, since it is much more convenient than keystroking ctrl+shift+p and running "typst-lsp.pinMainToCurrent" command. But honestly, we may leave it for another PR to reduce code changes, because I'm dumb and currently don't know how to bind it 😃.

I want to say that it is expected to leave many space for user customization. And we may discuss and equip lsp with more smart behaviors in future.

[PgBiel]

Awesome. We can definitely investigate that in the future. Thanks for the great work 👍

[SimonRask]

Looks great! I think this would solve #366.

I personally think it would be great to expose a configuration option such as typst-lsp.defaultMainFile, which would allow setting a default main file at the workspace level. It does not seem to be possible to test this in Helix currently, since I haven't found a way to pass the URI argument when running the typst-lsp.pinMainToCurrent command.

[Myriad-Dreamin]

@SimonRask Note that the typst-lsp program provides typst-lsp.doPinMain, and the vscode extension provides typst-lsp.pinMainToCurrent. typst-lsp.doPinMain receives an uri argument while typst-lsp.pinMainToCurrent doesn't. I don't know how we can get a such uri for main file in some helix extension, but I hope the above clarification could help you.

Since I don't use helix, it would be appreciate if you can verify it that current PR can work in helix by some way.

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typst-lsp.defaultMainFile looks good to me. To make typst-lsp.defaultMainFile correct, we may need to canonicalize path and convert it to a file url for comparison. Since current lsp doesn't canonicalize paths or urls at all, it is not quite easy and would need extra efforts to ensure correctness. So I think it could an optional feature in scope of this PR.

Now we may have two extra features in summary:

• In vscode or more editors, right-click them and select "Pin file" or something.
• For all editors, provide a typst-lsp.defaultMainFile configuration.

[SimonRask]

@Myriad-Dreamin

Note that the typst-lsp program provides typst-lsp.doPinMain, and the vscode extension provides typst-lsp.pinMainToCurrent. typst-lsp.doPinMain receives an uri argument while typst-lsp.pinMainToCurrent doesn't.

Sorry for the confusion. I meant typst-lsp.doPinMain instead of typst-lsp.pinMainToCurrent.

Since I don't use helix, it would be appreciate if you can verify it that current PR can work in helix by some way.

I will try to see if I can somehow pass arguments to typst-lsp.doPinMain. Note that this is not isolated to this PR, as it is also the case for typst-lsp.doPdfExport, for example.

Since current lsp doesn't canonicalize paths or urls at all, it is not quite easy and would need extra efforts to ensure correctness. So I think it could an optional feature in scope of this PR.

Agreed

[nvarner]

I'm not fully satisfied with this solution, but this is a big improvement over the status quo. I'll merge for now. Thank you!

[Myriad-Dreamin]

@nvarner should we create a tracking issue? For discussion on other perfect solutions or improving this solution.