JSVision

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Folding ​

Folding is a presentation over document ranges. The source remains unchanged while the viewport projects collapsed headers, hidden lines, and stable navigation targets.

Focused usage ​

ts
import { CodeEditor } from '@jsvision/code-editor';

const editor = new CodeEditor({ controller, lineNumbers: true });
editor.execute('fold.toggle');

Language-provided folds ​

A language adapter can return ranges that understand constructs such as functions, queries, and nested blocks. Apply only results produced for the current document revision.

Scan a substantial highlighted release formatter, collapse its real parser-provided regions, and observe how the document becomes easier to navigate without changing source.

Structural folds ​

Structure-derived folds are useful when a dedicated language parser is unavailable. Keep them separate from language ranges so the host can explain their origin and choose a predictable precedence.

Create a bounded structural region, collapse it, and verify that selection and revision remain stable.

Limits and practices ​

  • Normalize overlapping regions before publishing them to the controller.
  • Reject stale fold results after document revision changes.
  • Preserve a visible collapsed header and keyboard route; color alone is not sufficient.
  • Expand or remap folds when an edit invalidates their range.