Applying The Latest Engine And Script Changes

This lesson turns the imported changes into rules you can apply to your own cards. The source snapshot advances main scripts from b605741 to 14745a5a, core from 8b020270 to c4ccbab4, and adds the Rush library at 6916047c. The define repository has no new commits in this update.

Card Type And Current Type

The core now separates a card's card type from its effective current type. get_card_type() starts from database type and applies EFFECT_ADD_CARD_TYPE, EFFECT_REMOVE_CARD_TYPE, and EFFECT_CHANGE_CARD_TYPE. get_type() then handles current-state rules, including Pendulum Zone behavior and ordinary EFFECT_ADD_TYPE/REMOVE_TYPE/CHANGE_TYPE effects.

Question	API
What is its current effective type?	GetType, IsType, IsAllTypes
What type of card is it, including the new card-type changes?	GetCardType, IsCardType, IsAllCardTypes
What was that card type on the field before it moved?	GetPreviousCardTypeOnField, IsPreviousCardTypeOnField
What type was printed in its data?	GetOriginalType

IsCardType(mask) accepts any matching bit. IsAllCardTypes(mask) requires all of them. A filter for a “Normal Monster card” therefore uses:

function s.filter(c)
    return c:IsAllCardTypes(TYPE_NORMAL+TYPE_MONSTER)
end

Imported scripts such as c10007434.lua, c30752324.lua, and c45151304.lua use this distinction. Add a face-up, location, cost, or movement check when the particular card requires it; type alone does not prove the card is eligible.

The new effect codes are 377, 378, and 379 respectively. Use their symbolic names in scripts. Do not globally replace IsType: ordinary checks for the current monster/Spell/Trap state still need its existing behavior.

The running core must expose the API

Updating editor completion and documentation does not update the game's native core binary. A missing IsAllCardTypes method means the runtime and script snapshot differ. Replacing it with IsAllTypes changes the question being asked and can conceal the compatibility problem.

A Counter Mention Is Metadata

aux.HasMentionedCounter(c,counter) reads the script's mentioned_counter metadata. It does not check how many counters are currently on the card.

-- On a script whose text names this counter type:
s.mentioned_counter={[0x1]=true}

-- In a filter for cards whose text mentions that counter:
function s.filter(c)
    return aux.HasMentionedCounter(c,0x1)
end

Use Card.GetCounter for a live counter count and the Counters lesson for counter placement and removal. Metadata, permissions, and counters currently present are separate concerns.

Three Small Fixes With Large Effects

Check Numeric Action Results

Upstream 0200c677d corrected c43419178.lua:

if tc and Duel.SendtoGrave(tc,REASON_EFFECT)>0
    and tc:IsLocation(LOCATION_GRAVE) then
    -- Continue with the dependent action.
end

Lua treats zero as true. A bare if Duel.SendtoGrave(...) then cannot tell success from a zero result. The location check also verifies that this card reached the destination required by the next action.

Guard Subgroup Results

Upstream 78175e702 corrected many subgroup selections:

local selected=g:SelectSubGroup(tp,s.groupcheck,false,2,2)
if not selected then return end
-- Use selected only after the nil guard.

This is a callback fragment: g is your candidate Group and s.groupcheck is the card's group predicate. Keep CheckSubGroup legality checks where needed, but still guard the returned selection before dereferencing it.

Use Inequality For Numeric Tests

Upstream e74a16853 fixed not c:GetAttack()==0 to c:GetAttack()~=0 in c2606417.lua. not binds before ==; the original expression compared a Boolean with zero. See Lua Essentials for a short exercise.

Updated Hint Names

New code should use HINTMSG_NUMBER and HINTMSG_LVRANK. The misspelled HINGMSG_NUMBER and HINGMSG_LVRANK remain compatibility aliases in this snapshot. The correctly spelled names make completion and source searches consistent; there is no need to rewrite unrelated logic around them.

Review An Existing Card

1. Read the changed card text and its new script together.
2. Determine whether a changed predicate asks about current type, card type, printed type, or previous state.
3. Check action return values and possible nil selections.
4. Test a legal state, an illegal state, and a state that changes before resolution. Add a second-copy test for name-based count limits.
5. For Rush, follow the Rush track and verify the shared helper implementation as well as the card script.

The source trail is the companion ygopro-core repository's card.cpp and libcard.cpp, this repository's Utilities/utility.lua and Utilities/constant.lua, and the card scripts named above. The function reference links individual calls to the source snapshot.