ss-lang for VS Code

VS Code language support for ss slide source files.

Requirements

This extension does not bundle the ss CLI. Install ss first, then keep it on PATH or set ss.cli.path.

See the installation guide in the project README.

Project Files

Editor features use the same project discovery as the CLI. Put ss.toml at your workspace or deck root:

[project]
entry = "slide.ss"
asset_base_dir = "."

entry is required. asset_base_dir defaults to the entry file's parent directory when omitted.

Editor behavior can also be configured in ss.toml:

[editor.lsp]
enabled = true
debounce = 120
diagnostics = true
completion = true
hover = true
definition = true
document_symbols = true
folding_ranges = true
semantic_tokens = true
colors = true

[editor.lsp.inlay_hints]
enabled = true
arguments = true
positions = true

[editor.preview]
enabled = true
debounce = 350
open = "vscode"
reveal = true

[editor.preview.refresh]
save = true
dependency = true

[editor.preview.render]
timeout = 30000
extra_args = []

[editor.preview.path]
output = ".ss-cache/vscode-preview"

[editor.page_guide]
enabled = true
body_background = true
boundary = true
boundary_background = true
gutter_icon = true
overview_ruler = true

The repository ships a JSON Schema for ss.toml at schemas/ss-toml.schema.json. TOML language servers such as Taplo can use it for completion and validation. In a deck repository, add a Taplo rule like:

[[rule]]
include = ["**/ss.toml"]
schema.path = "schemas/ss-toml.schema.json"

If .ss Opens As Scheme

Some VS Code setups already associate .ss with Scheme.

Add this to your workspace settings:

{
  "files.associations": {
    "*.ss": "ss-slide"
  }
}

Live Preview

Live preview renders saved project files. Normal LSP diagnostics continue to use open editor buffers, but PDF output and render-phase diagnostics update from the files on disk when the deck or a dependency is saved or changed. This covers backend errors such as TeX math rendering failures. Opening or closing the PDF preview only controls the viewer; render diagnostics continue to use the normal editor refresh settings.

Run ss: Open Live Preview from the command palette or the editor title button. The preview asks the language server for ss/projectInfo and refreshes a PDF with:

ss render <project-entry> .ss-cache/vscode-preview/<file>.pdf --asset-base-dir <project-asset-base> --cache-id <project-entry>

With the default [editor.preview].open = "vscode", the extension opens its own PDF.js webview. The webview loads a loopback viewer page, and the extension serves the generated PDF plus the bundled PDF.js assets from that local server while the preview is open. Later renders update the registered PDF and send a refresh message to the viewer, preserving the current page, zoom, and scroll position where possible. Set [editor.preview].open to external in ss.toml to open the generated PDF in the operating system's PDF application:

[editor.preview]
open = "external"