Function completion_context 

pub fn completion_context(doc: &CstDocument, offset: usize) -> CompletionContext

Analyze the cursor offset against doc and produce a CompletionContext (FR-010/FR-011/FR-012/FR-014).

Read-only. The offset is a byte offset into the source the document was parsed from; an out-of-range offset is clamped to the source length. An empty / whitespace-only document, a cursor with no enclosing construct, or a position whose kind cannot be uniquely resolved all yield an empty context (no items, no error) per the empty/ambiguous-suppression rule (FR-014).