feat: grammar-based value completion#494
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The frontier built for error localization answers exactly the question
completion needs — "what was expected at this offset?" is "what could come next
here?". Adds Combinator.nextTokenChoices(prefix), which reads the Stuck values at
the end of the typed prefix and collects the enumerable choices expected there
(literal / flexible-literal terminals; numbers/regexes/whitespace contribute
nothing to suggest).
Wires it into UnitFileValueCompletionContributor, gated behind
ExperimentalSettings.useGrammarParseEngine AND validator is GrammarOptionValue:
with the flag off the existing completion path is untouched. Two behaviours:
- completing a partial token (sets the prefix matcher so "AF_IN" -> AF_INET/6)
- chaining through forced separators on accept (e.g. accepting "home" inserts
"home=" and re-opens completion, never auto-inserting a content token)
Bundles the stacked PRs #477 (completion) and #478 (forced-separator chaining),
re-cut against current 242.x. New behaviour, so flag-gated; correctness of
existing validators is unchanged. Tests enable the flag and reset it in tearDown
to avoid leaking into the shared light-test project.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
SJrX
changed the title
The completion bundle tested the flag-on behaviours but not two things worth guaranteeing: that grammar completion stays suppressed when the experimental engine is off (the gating contract), and that a non-enumerable next token (number/regex) offers nothing rather than crashing or suggesting junk. - GrammarValueCompletionTest.testFlagOffOffersNoGrammarCompletions: flag off, the AF_IN partial yields no AF_* names (the flag-on path's suggestions are absent). - NextTokenChoicesTest.testNonEnumerableNextTokenOffersNothing: an IntegerTerminal port grammar returns an empty choice set. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Unit Test Results (grammar engine false)1 152 tests 1 152 ✅ 51s ⏱️ Results for commit da375e2. |
Unit Test Results (grammar engine true)1 152 tests 1 152 ✅ 50s ⏱️ Results for commit da375e2. |
This was referenced Jun 27, 2026
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What
Grammar-driven value completion for
GrammarOptionValueoptions. The frontier we built for error localization (theStuck/expectedset, already on 242.x) answers exactly what completion needs — "what was expected at this offset?" is the same question as "what could come next here?".Adds
Combinator.nextTokenChoices(prefix)(pure Kotlin, no IntelliJ types): parse the typed prefix, read theStuckvalues whose offset is the end of the prefix, and collect the enumerable choices of the terminals expected there (LiteralChoiceTerminal/FlexibleLiteralChoiceTerminal; numbers/regexes/whitespace/EOF contribute nothing to suggest).Gating (important)
Wired into
UnitFileValueCompletionContributorbehind:This is new behaviour, so it's gated behind the experimental flag — with the flag off, completion behaves exactly as before. (Correctness fixes to existing validators stay default; new behaviours opt in.)
Two behaviours
RestrictAddressFamilies=AF_IN⎮offersAF_INET/AF_INET6(rather than the lenient terminal treatingAF_INas a finished token).home→home=), then re-open completion — never auto-inserting a content token the user should pick.Scope
Bundles stacked PRs #477 (completion) + #478 (forced-separator chaining), re-cut against current 242.x. The AF-family completion works because #492's enumerated AF validator is now on 242.x.
Verification
./gradlew testand./gradlew test -Dsystemd.unit.grammarParseEngine=trueboth pass. Tests enable the flag and reset it intearDownso it doesn't leak into the shared light-test project.🤖 Generated with Claude Code