Limitations

Known constraints and unsupported behavior. Updated as the parser and LSP mature.

Shipped today

Rust crates (spice-parser, spice-lsp, spice-reference), Tree-sitter grammar, and VS Code extension
Syntax diagnostics plus semantic warnings (spice/duplicate-name, spice/unknown-model, include/lib path issues)
Document outline, go to definition, and find references
Dialect-aware hover from the curated reference/ corpus (default HSPICE) plus file-local pin/model detail
.include / .lib resolution for model and subcircuit definitions
Document formatting (textDocument/formatting) and spice-lsp format CLI
Debounced diagnostics on edit; textDocument/references honors includeDeclaration
Marketplace extension with bundled binaries, TextMate highlighting, and restart command
File associations for .cir, .sp, .spf, .net, .ckt, .inc, and .lib

Limitation	Workaround
Shared grammar for all dialects	Prefer common SPICE constructs; dialect-specific parse quirks grow over time; hover/docs already switch
No connectivity analysis	Manual review until dangling/floating checks land
Include graph is definition-focused	`.include` / `.lib` resolve models and subcircuits for diagnostics and go-to-definition; outline and find-references stay file-local — see Include and library resolution
No completion yet	Type element/directive names manually
Formatter has no dialect profiles yet	Shared alignment/casing rules for all dialects; see Formatter
Comment toggle uses `*` only	`;` and `$` are highlighted as comments; VS Code allows one `lineComment`
No Windows arm64 bundled binary	Set `spiceLsp.serverPath` or put `spice-lsp` on `PATH`
Linux bundled binary needs glibc 2.31+	Upgrade the host OS, or build `spice-lsp` locally and set `spiceLsp.serverPath`
Bare numeric lines outside `.DATA`	Prefer `+` continuations or keep value rows inside `.DATA` … `.ENDDATA`

The reference library under reference/ grows incrementally:

Shared baseline covers common directives (.subckt, .tran, .dc, .op, .ac, …) and elements (R, C, X)
HSPICE overlays expand analysis/control docs (.data, multi-mode .dc, .op, .measure, .probe, .lib, …) — see Dialect reference catalog
LTspice remains a stub corpus; missing entry → no hover (not an error)
Reference describes language constructs, not simulator version release notes

Dangling-node and floating-net diagnostics will be heuristic:

Limitation	Detail
Single file	Net connectivity still ignores `.include` until a full cross-file net graph exists
Ground aliases	Defaults to `0`, `gnd`, `GND`; exotic ground names may need config
False positives	Intentionally open probe points may warn until suppression exists
Not full ERC	Does not check layout, EM, or foundry rules
Ideal elements	Voltage sources and unusual topologies need careful graph rules

These warnings supplement — not replace — simulator and layout review.

Area	Ngspice	LTspice	HSPICE
Comments	`*`, `;`, `$`	`$` common	`*`
Directives / options	Baseline corpus	Overrides in `reference/ltspice/`	Overrides in `reference/hspice/`

Parsing is still largely Ngspice-oriented; reference namespaces already switch with spiceLsp.dialect.

Error recovery may leave incomplete indexes until syntax is fixed
Very large files still re-parse the full buffer after the debounce window (Tree-sitter incremental reuse is not wired yet)
Large / extracted netlists use extracted analysis mode above spiceLsp.extractedByteThreshold (default 16 MiB, or when spiceLsp.analysisMode is extracted): definitions-only indexing, no instance outline/symbols, no duplicate-name scan — see Large-file / extracted mode
LSP assumes UTF-8 source

UTF-16 positions per LSP spec
Stdio transport only
No workspace-wide symbol search yet (include graph is used for definitions, not workspace/symbol)
Diagnostics on didChange are debounced (~150 ms); navigation requests re-analyze on demand so the index stays current

Include:

Add a fixture under test-data/ when fixing.