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VS Code Extension

The Wvlet extension provides syntax highlighting and language support for .wv files in Visual Studio Code.

Installation​

Install from the VS Code Marketplace or search for "Wvlet" in VS Code's Extensions view.

Features​

  • Syntax Highlighting: Full support for Wvlet keywords, operators, and syntax
  • Bracket Matching: Automatic matching for {}, [], (), and ${}
  • Comment Support: Single-line (--) and multi-line (---) comments
  • String Interpolation: Highlighting for ${...} expressions
  • Auto-closing: Brackets and quotes automatically close when typed
  • Diagnostics: Compilation errors are reported inline as you edit
  • Document Outline: Models, types, vals, and flows appear in the outline view
  • Code Completion: Context-aware suggestions as you type
  • Hover Information: Type and schema details when you hover over models and columns
  • Go to Definition: Jump from a model or type reference to its definition, also across workspace files

Code Completion​

The extension suggests candidates while you write a query. Completion is triggered automatically as you type or on demand with Ctrl+Space, and offers:

  • Keywords: Wvlet language keywords such as from, select, and where
  • Model & definition names: Models, types, vals, and flows defined in the current file and in other workspace files, including table types from an imported catalog
  • Column names: Columns available at the cursor, resolved from the query's input relation (for example, after from and inside select or where)
  • Function names: Well-known SQL functions such as count and regexp_replace

Typing . after a table alias or table name suggests only that relation's columns, and typing . after a schema name suggests the tables of that schema (from an imported catalog) — for example orders. lists the order columns, and sales. lists the tables of the sales schema.

Column suggestions rely on type resolution, so they appear once the surrounding query is complete enough to be analyzed. Outside member-access contexts, keyword and definition suggestions are always available, including while a query is still being written.

Hover Information​

Hover over a symbol to see its type information in a tooltip:

  • Models: The model signature — its name, parameters, and output schema (each column with its type)
  • Columns: The column name and its resolved data type, for example name: string
  • Type definitions: The declared fields of a type

Hover relies on type resolution, so it appears once the surrounding query is complete enough to be analyzed. When the cursor is not on a symbol with a resolved type, no tooltip is shown.

Go to Definition​

Place the cursor on a model or type reference and use Go to Definition (F12, or Cmd/Ctrl + click) to jump to the model or type statement that defines it. For example, from from my_model you can jump to the model my_model = ... definition, and from a type reference to its type declaration.

Go to Definition works across the files of your workspace: a reference to a model or type defined in another .wv file — including table types imported into the catalog/ folder by wvlet catalog import — opens the defining file at the definition. When the same name is defined both in the current file and elsewhere, the definition in the current file wins.

Working with Database Tables​

The language server loads the .wv sources of your workspace folder (the first folder in a multi-root workspace), including the catalog/ folder generated by wvlet catalog import. After importing your database catalog once, table references such as from sales.orders resolve offline in the editor: diagnostics validate them, hover shows their columns, and column names complete — no live database connection needed.

Note: source discovery follows the compiler's folder scan, which descends into folders that contain .wv files (plus the catalog/ folder, which is always loaded). Keep at least one .wv file at the workspace root — or open the folder that holds your queries — so nested sources are found.

Known Limitations​

  • Schema for database tables: Tables get completion and hover only when their schema is known — from a model/type definition in the workspace or from an imported catalog (see above). File sources such as from 'data.json' do not yet carry a schema in the editor.
  • Requires an analyzable query: Column completion and hover rely on type resolution, so they appear once the surrounding query is complete enough to be analyzed. While a query is still being written, keyword and definition-name suggestions remain available.

Example​

Wvlet syntax highlighting in VS Code

Pre-release Versions​

To try new features early, switch to the pre-release version from the extension's settings in VS Code.