qpl for VSCode

Editor support for qpl — the Quick Polars Query Language.

Features

Syntax highlighting

.qpl files get highlighting for comments (/), double-quoted strings with escapes, symbols and symbol vectors (`a`b`c), integer / float / bool / bool-vector literals, statement keywords (select, by, from, where, over, order, asc, desc, distinct, limit, drop, update, delete), builtin keywords (load, sink, cols, lazy, collect) and .qpl.* builtin functions (.qpl.cfg), aggregates (sum, avg, count, round, ...), cast types (f64$x), the operator functions ? $ :: ! #, join operators (lj, ij, rj), the like glob-match operator, the IPC client (hopen, await, dispatch/async dispatch — ipc feature), assignments, function literals ({[x,y] ..} — braces and parameter names), \d / \l / \1 / \port REPL lines, and the virtual i column. Plus line comments, bracket matching and auto-closing pairs for {}, [], () and ".

Braces and indentation

Braces are matched, auto-closed and surroundable like brackets, but they indent differently, because qpl's own continuation rule decides where a function body ends: a line indented by a tab or 4+ spaces continues the statement above it, so a function's closing } has to stay inside the body indent. Outdenting it to the opening line's column — what an editor normally does with } — makes the function unterminated and the script fails to parse.

So the closing brace is never auto-outdented: pressing Enter inside { } indents the body and leaves } at that indent, and typing } on an indented line leaves it where it is. The extension also pins editor.tabSize to 4 with spaces for .qpl files, since a 2-space indent is below what the interpreter counts as a continuation.

Completion & snippets

• Statement/builtin keywords and REPL commands (\d, \1, \l, log) at the start of a line; aggregates (sum, avg, round, rn, rank, ...) everywhere.
• Cast type names (f64, int, str, ...) right after $.
• Table names after from / by / drop / collect / sink / load: tables assigned or referenced in the open document, plus the configurable qpl.demoTables (default trades, quotes).
• Variables assigned in the open document (name: ...).
• Snippets: sel, selby, upd, del, delcols, join, lazyp, cond, over, fn, lambda.

Interactive REPL

• Ctrl+Enter (Cmd+Enter on macOS) in a .qpl file runs the selection, or the whole file when nothing is selected, in a persistent qpl REPL terminal. State (tables, variables) carries across runs, like a Python REPL.
• Multi-line / multi-statement input is handed to the interpreter via \l (run-script), so its own continuation-folding and comment handling apply.
• Commands (Command Palette): qpl: Start REPL, qpl: Restart REPL, qpl: Run File or Selection in REPL.

Finding the qpl binary

The extension resolves, in order:

1. the qpl.path setting, if set;
2. qpl on your PATH;
3. target/release/qpl or target/debug/qpl in the workspace;
4. cargo run --quiet --manifest-path <workspace>/Cargo.toml -- when a qpl Cargo.toml is present (handy while hacking on qpl itself).

Set qpl.loadDemo to start the REPL with the demo trades / quotes tables. Set qpl.demoTables to change which table names completion offers by default (alongside whatever it finds in the open document).

Developing

cd tools/vscode
npm install
npm run compile          # or: npm run watch
# then press F5 in VSCode to launch an Extension Development Host with the
# ../../examples folder open. `npm: compile` runs automatically before launch.

Packaging

vsce (Visual Studio Code Extensions) turns the folder into a distributable .vsix:

npm install -g @vscode/vsce   # one-time
vsce package                  # runs `npm run compile`, then writes qpl-<version>.vsix

vsce package reads package.json, runs the vscode:prepublish script (tsc), bundles every file not excluded by .vscodeignore, and validates the manifest. Install the result with Extensions view → ··· → Install from VSIX… or code --install-extension qpl-<version>.vsix — no Marketplace account needed.

To publish to the Marketplace you need a publisher matching an Azure DevOps organisation and a Personal Access Token: vsce login <publisher> then vsce publish.