Add position encoding negotiation support#4
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LSP 3.17 lets the client and server negotiate how positions are encoded (what column offsets mean), rather than always assuming UTF-16. - Add PositionEncodingKind (utf-8 / utf-16 / utf-32) per the spec's base type. - Add GeneralClientCapabilities so clients can advertise supported encodings via general.positionEncodings, wired into ClientCapabilities. - Add ServerCapabilities carrying the server-chosen positionEncoding. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
christiankissig
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Jul 7, 2026
Add position encoding negotiation support
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Summary
Adds support for position encoding negotiation as introduced in LSP 3.17 — Text Documents.
Prior to 3.17, all positions (column offsets) were assumed to be UTF-16 code units. Since 3.17 the client and server can agree on a different encoding:
general.positionEncodingscapability.positionEncodingserver capability. If there is no match, UTF-16 is the mandatory default.Changes
PositionEncodingKind— string enum withutf-8/utf-16/utf-32, matching the spec's base type.GeneralClientCapabilities— new model exposingpositionEncodings(plus the other general sub-capabilities); wired intoClientCapabilities.general(previously a baredict).ServerCapabilities— new model carrying the negotiatedpositionEncoding.lsp_client.Testing
InitializeRequestwire output, and the server capability.poetry run pytest(38 passed),ruff check,ruff format --check, andmypyall clean.🤖 Generated with Claude Code