fix(parser): recognize "land types" in the loses-all enumeration (Alpine Moon, Lithoform Blight, Ultima)

[claytonlin1110]

Closes #6270. Also explains and closes #4222.

Summary

A continuous static of the form <subject> loses all land types and abilities [and has/gain "<ability>"] silently dropped the entire type/ability-removal clause, keeping only the granted ability. Alpine Moon, Lithoform Blight, and Ultima, Origin of Oblivion all use this exact "loses all land types and abilities" phrasing, and none of them removed the affected land's original type/abilities before this fix.

Files changed

• crates/engine/src/parser/oracle_static/grammar.rs
• crates/engine/src/parser/oracle_static/keyword_grant.rs
• crates/engine/src/parser/oracle_static/tests.rs

CR references

• CR 205.3i — land types are a land's own subtype set.
• CR 613.1d — Layer 4 (type-changing effects) — the subtype removal.
• CR 613.1f — Layer 6 (ability-adding/ability-removing effects) — the ability removal, composed with the granted mana ability in written order (CR 613.6).

Root cause

oracle_static/grammar.rs's LossMember enum models the "loses all <list>" enumeration as a closed 3-member set (Abilities / CardTypes / CreatureTypes). parse_loss_enumeration's separated_list1 requires every item in the comma-and list to match one of the three alt arms; "land types" matches none of them, so the list parse fails at the first token and scan_loss_enumeration returns an empty Vec for every scan window. parse_continuous_modifications's loss loop (keyword_grant.rs) then pushes nothing for the whole clause — the card still reports as fully parsed (no Unimplemented residual) because the trailing granted-ability clause parses fine on its own, so the drop is silent.

parse_continuous_modifications is the same shared composing authority already generalized twice for this exact bug shape — a compound predicate where a narrow enumeration/dispatch gap lets one clause vanish while the rest of the line still "succeeds": the color-defining static fix (#5807, SetColor dropped when composed with a keyword) and the additive-type-clause fix (#6081, a granted quoted ability dropped the additive type). This is the same function, the same missing-enumeration-member shape, on a different axis (CR 205.3i land types).

The engine runtime side needed zero changes — SubtypeSet::Land already exists (crates/engine/src/types/card_type.rs) and game/layers.rs already has a working RemoveAllSubtypes { set: Land } arm. This is a pure parser-wiring fix.

Fix

• grammar.rs: add LossMember::LandTypes and a fourth value(LossMember::LandTypes, tag("land types")) arm to the enumeration alt (no ordering hazard — none of the four tags share a prefix).
• keyword_grant.rs: add the corresponding LossMember::LandTypes => modifications.push(ContinuousModification::RemoveAllSubtypes { set: SubtypeSet::Land }) arm, mirroring the existing CreatureTypes arm.
• tests.rs: a building-block test (scan_loss_enumeration_recognizes_land_types) mirroring the existing CreatureTypes coverage, plus two production-path regression tests parsing Lithoform Blight's and Alpine Moon's actual Oracle text and asserting RemoveAllSubtypes { Land } + RemoveAllAbilities + the granted GrantAbility(s) all compose.

Parse diff (Lithoform Blight, Enchanted land loses all land types and abilities and has "{T}: Add {C}" and "{T}, Pay 1 life: Add one mana of any color.")

Before — the type/ability removal is dropped:

modifications: [ GrantAbility { "{T}: Add {C}" }, GrantAbility { "{T}, Pay 1 life: Add one mana of any color" } ]

After:

modifications: [ RemoveAllAbilities, RemoveAllSubtypes { Land }, GrantAbility { "{T}: Add {C}" }, GrantAbility { "{T}, Pay 1 life: Add one mana of any color" } ]

Anchored on

• crates/engine/src/parser/oracle_static/grammar.rs (LossMember / parse_loss_enumeration / scan_loss_enumeration) — the existing 3-member loss-enumeration seam this extends to 4. CreatureTypes is the direct structural sibling: same RemoveAllSubtypes runtime, same enumeration position, same test-authoring pattern (static_nonlegendary_creatures_enchanted_player_controls_base_pt_and_lose_types, Curse of Conformity).
• crates/engine/src/parser/oracle_static/keyword_grant.rs (parse_continuous_modifications's loss loop) — mirrors the existing CreatureTypes => RemoveAllSubtypes { set: Creature } arm one line above the new LandTypes arm.
• crates/engine/src/game/layers.rs (RemoveAllSubtypes { set } => match set { ... SubtypeSet::Land => ... }) — confirmed the runtime arm for Land already exists and is exercised elsewhere, so no engine change was needed, only the parser wiring.

Claimed parse impact

• Alpine Moon
• Lithoform Blight
• Ultima, Origin of Oblivion (via the trigger's duration-gated grant, same shared composer)
• the general <subject> loses all land types and abilities [and has/gain <ability>] class

Verification

I could not run cargo test / cargo clippy / cargo build locally in this session — this environment's Rust toolchain has no usable linker for the x86_64-pc-windows-msvc target (no MSVC Build Tools or Windows SDK installed, and no WSL/Docker/Tilt available as a fallback; confirmed the linker gap is total, not just a PATH shadowing issue, by checking for kernel32.lib etc. anywhere on the machine). cargo fmt --all does work (no linking involved) and ran clean over this diff with no other changes.

In place of running the suite, I verified by hand, tracing the actual source at the cited line numbers:

• LossMember's only exhaustive match (keyword_grant.rs) is updated with the new arm; the one other reference (type_change.rs, a non-exhaustive matches!(m, LossMember::CardTypes)) is unaffected by the new variant.
• SubtypeSet::Land and its RemoveAllSubtypes runtime arm in game/layers.rs already exist and are already exercised by other tests, so the new modification is not a dead end at resolution time.
• Every type/variant/field name used in the new tests (TargetFilter::And, TargetFilter::Typed, TypeFilter::Land, ControllerRef::Opponent, TargetFilter::HasChosenName, ContinuousModification::RemoveAllSubtypes/RemoveAllAbilities/GrantAbility) was copied from currently-existing, already-passing sibling tests in the same file (static_nonlegendary_creatures_enchanted_player_controls_base_pt_and_lose_types / Curse of Conformity for the loss-enumeration shape; lands_with_chosen_name_grant_quoted_ability / Petrified Hamlet for the And[Typed(Land), HasChosenName] subject shape), not invented.
• All three affected cards' Oracle text was pulled verbatim from data/mtgjson/AtomicCards.json and cross-checked byte-for-byte against the quotes in this PR and in parser: "loses all land types and abilities" enumeration doesn't recognize "land types" (Alpine Moon, Lithoform Blight, Ultima) #6270.

I'd appreciate CI (and/or a maintainer with a working local toolchain) confirming the actual cargo test -p engine --lib parser:: / cargo clippy run, since I was not able to produce that signal myself this session.

Track

Developer

LLM

Model: claude-sonnet-5

[gemini-code-assist]

Code Review

This pull request adds support for parsing and handling the loss of land types (e.g., 'loses all land types and abilities') by introducing the LossMember::LandTypes enum variant, updating the parser to recognize 'land types' using nom combinators, and mapping it to the RemoveAllSubtypes modification for the Land subtype set. All changes are properly annotated with the relevant Comprehensive Rules (CR 205.3i). There are no review comments, and I have no feedback to provide.

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[github-actions]

Parse changes introduced by this PR · 3 card(s), 3 signature(s) (baseline: main f983c0f55b5d)

🟢 Added (1 signature)

• 1 card · ➕ ability/remove all Land subtypes, remove all abilities, grant ability · added: remove all Land subtypes, remove all abilities, grant ability (affects=parent target, duration=for as long as condition, grants=grant ability, grants=remove al…
  • Affected (first 3): Ultima, Origin of Oblivion

🔴 Removed (1 signature)

• 1 card · ➖ ability/grant ability · removed: grant ability (affects=parent target, duration=for as long as condition, grants=grant ability, target=parent target)
  • Affected (first 3): Ultima, Origin of Oblivion

🟡 Modified fields (1 signature)

• 2 cards · 🔄 static/Continuous · changed field mods: ∅ → remove all Land subtypes, remove all abilities
  • Affected (first 3): Alpine Moon, Lithoform Blight

1 card(s) had Oracle-text changes (errata/reprint) — excluded as non-parser.

[matthewevans]

Maintainer review complete: current-head parser change is at the existing LossMember authority; the current parse-diff is limited to Alpine Moon, Lithoform Blight, and Ultima.