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NextAction refactoring to eliminate sentinel arrays and pointers (#1923)

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# Description

This PR aims to refactor the NextAction declaration to achieve two
goals:

## Eliminate C-style sentinel arrays

Currently, a double pointer (`NextAction**`) approach is being used.
This an old pre-C++11 (< 2011) trick before `std::vector<>` became a
thing.
This approach is painful for developers because they constantly need to
declare their `NextAction` arrays as:
```cpp
NextAction::array(0, new NextAction("foo", 1.0f), nullptr)
```
Instead of:
```cpp
{ new NextAction("foo", 1.0f) }
```
The first argument of `NextAction::array` is actually a hack. It is used
to have a named argument so `va_args` can find the remaining arguments.
It is set to 0 everywhere but in fact does nothing. This is very
confusing to people unfamiliar with this antiquated syntax.
The last argument `nullptr` is what we call a sentinel. It's a `nullptr`
because `va_args` is looking for a `nullptr` to stop iterating. It's
also a hack and also leads to confusion.

## Eliminate unnecessary pointers for `NextAction`

Pointers can be used for several reasons, to cite a few:
- Indicate strong, absolute identity.
- Provide strong but transferable ownership (unlike references).
- When a null value is acceptable (`nullptr`).
- When copy is expensive.

`NextAction` meets none of these criteria:
- It has no identity because it is purely behavioural.
- It is never owned by anything as it is passed around and never fetched
from a registry.
- The only situations where it can be `nullptr` are errors that should
in fact throw an `std::invalid_argument` instead.
- They are extremely small objects that embark a single `std::string`
and a single `float`.

Pointers should be avoided when not strictly necessary because they can
quickly lead to undefined behaviour due to unhandled `nullptr`
situations. They also make the syntax heavier due to the necessity to
constantly check for `nullptr`. Finally, they aren't even good for
performance in that situation because shifting a pointer so many times
is likely more expensive than copying such a trivial object.

# End goal

The end goal is to declare `NextAction` arrays this way:
```cpp
{ NextAction("foo", 1.0f) }
```

> [!NOTE]
> Additional note: `NextAction` is nothing but a hacky proxy to an
`Action` constructor. This should eventually be reworked to use handles
instead of strings. This would make copying `NextAction` even cheaper
and remove the need for the extremely heavy stringly typed current
approach. Stringly typed entities are a known anti-pattern so we need to
move on from those.
This commit is contained in:
Nicolas Lebacq
2026-01-06 11:37:39 +00:00
committed by GitHub
parent b13fb7d12a
commit c9cc4324d3
197 changed files with 6795 additions and 4054 deletions
Download Patch File Download Diff File Expand all files Collapse all files

159
src/strategy/deathknight/FrostDKStrategy.cpp
View File

@@ -16,66 +16,68 @@ public:
creators["obliterate"] = &obliterate;
creators["howling blast"] = &howling_blast;
creators["frost strike"] = &frost_strike;
// creators["chains of ice"] = &chains_of_ice;
creators["rune strike"] = &rune_strike;
// creators["icy clutch"] = &icy_clutch;
// creators["horn of winter"] = &horn_of_winter;
// creators["killing machine"] = &killing_machine;
// creators["frost presence"] = &frost_presence;
// creators["deathchill"] = &deathchill;
// creators["icebound fortitude"] = &icebound_fortitude;
// creators["mind freeze"] = &mind_freeze;
// creators["hungering cold"] = &hungering_cold;
creators["unbreakable armor"] = &unbreakable_armor;
// creators["improved icy talons"] = &improved_icy_talons;
}
private:
static ActionNode* icy_touch([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("icy touch",
/*P*/ NextAction::array(0, new NextAction("blood presence"), nullptr),
/*A*/ nullptr,
/*C*/ nullptr);
return new ActionNode(
"icy touch",
/*P*/ { NextAction("blood presence") },
/*A*/ {},
/*C*/ {}
);
}
static ActionNode* obliterate([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("obliterate",
/*P*/ NextAction::array(0, new NextAction("blood presence"), nullptr),
/*A*/ nullptr,
/*C*/ nullptr);
return new ActionNode(
"obliterate",
/*P*/ { NextAction("blood presence") },
/*A*/ {},
/*C*/ {}
);
}
static ActionNode* rune_strike([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("rune strike",
/*P*/ NextAction::array(0, new NextAction("blood presence"), nullptr),
/*A*/ NextAction::array(0, new NextAction("melee"), nullptr),
/*C*/ nullptr);
return new ActionNode(
"rune strike",
/*P*/ { NextAction("blood presence") },
/*A*/ { NextAction("melee") },
/*C*/ {}
);
}
static ActionNode* frost_strike([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("frost strike",
/*P*/ NextAction::array(0, new NextAction("blood presence"), nullptr),
/*A*/ nullptr,
/*C*/ nullptr);
return new ActionNode(
"frost strike",
/*P*/ { NextAction("blood presence") },
/*A*/ {},
/*C*/ {}
);
}
static ActionNode* howling_blast([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("howling blast",
/*P*/ NextAction::array(0, new NextAction("blood presence"), nullptr),
/*A*/ nullptr,
/*C*/ nullptr);
return new ActionNode(
"howling blast",
/*P*/ { NextAction("blood presence") },
/*A*/ {},
/*C*/ {}
);
}
static ActionNode* unbreakable_armor([[maybe_unused]] PlayerbotAI* botAI)
{
return new ActionNode("unbreakable armor",
/*P*/ NextAction::array(0, new NextAction("blood tap"), nullptr),
/*A*/ nullptr,
/*C*/ nullptr);
return new ActionNode(
"unbreakable armor",
/*P*/ { NextAction("blood tap") },
/*A*/ {},
/*C*/ {}
);
}
};
@@ -84,41 +86,84 @@ FrostDKStrategy::FrostDKStrategy(PlayerbotAI* botAI) : GenericDKStrategy(botAI)
actionNodeFactories.Add(new FrostDKStrategyActionNodeFactory());
}
NextAction** FrostDKStrategy::getDefaultActions()
std::vector<NextAction> FrostDKStrategy::getDefaultActions()
{
return NextAction::array(
0, new NextAction("obliterate", ACTION_DEFAULT + 0.7f),
new NextAction("frost strike", ACTION_DEFAULT + 0.4f),
new NextAction("empower rune weapon", ACTION_DEFAULT + 0.3f),
new NextAction("horn of winter", ACTION_DEFAULT + 0.1f), new NextAction("melee", ACTION_DEFAULT), NULL);
return {
NextAction("obliterate", ACTION_DEFAULT + 0.7f),
NextAction("frost strike", ACTION_DEFAULT + 0.4f),
NextAction("empower rune weapon", ACTION_DEFAULT + 0.3f),
NextAction("horn of winter", ACTION_DEFAULT + 0.1f),
NextAction("melee", ACTION_DEFAULT)
};
}
void FrostDKStrategy::InitTriggers(std::vector<TriggerNode*>& triggers)
{
GenericDKStrategy::InitTriggers(triggers);
triggers.push_back(new TriggerNode(
"unbreakable armor", NextAction::array(0, new NextAction("unbreakable armor", ACTION_DEFAULT + 0.6f), nullptr)));
triggers.push_back(new TriggerNode(
"freezing fog", NextAction::array(0, new NextAction("howling blast", ACTION_DEFAULT + 0.5f), nullptr)));
triggers.push_back(new TriggerNode(
"high blood rune", NextAction::array(0, new NextAction("blood strike", ACTION_DEFAULT + 0.2f), nullptr)));
triggers.push_back(new TriggerNode(
"army of the dead", NextAction::array(0, new NextAction("army of the dead", ACTION_HIGH + 6), nullptr)));
triggers.push_back(
new TriggerNode(
"unbreakable armor",
{
NextAction("unbreakable armor", ACTION_DEFAULT + 0.6f)
}
)
);
triggers.push_back(
new TriggerNode("icy touch", NextAction::array(0, new NextAction("icy touch", ACTION_HIGH + 2), nullptr)));
triggers.push_back(new TriggerNode(
"plague strike", NextAction::array(0, new NextAction("plague strike", ACTION_HIGH + 2), nullptr)));
// triggers.push_back(new TriggerNode("empower rune weapon", NextAction::array(0, new NextAction("empower rune
// weapon", ACTION_NORMAL + 4), nullptr)));
new TriggerNode(
"freezing fog",
{
NextAction("howling blast", ACTION_DEFAULT + 0.5f)
}
)
);
triggers.push_back(
new TriggerNode(
"high blood rune",
{
NextAction("blood strike", ACTION_DEFAULT + 0.2f)
}
)
);
triggers.push_back(
new TriggerNode(
"army of the dead",
{
NextAction("army of the dead", ACTION_HIGH + 6)
}
)
);
triggers.push_back(
new TriggerNode(
"icy touch",
{
NextAction("icy touch", ACTION_HIGH + 2)
}
)
);
triggers.push_back(
new TriggerNode(
"plague strike",
{
NextAction("plague strike", ACTION_HIGH + 2)
}
)
);
}
void FrostDKAoeStrategy::InitTriggers(std::vector<TriggerNode*>& triggers)
{
triggers.push_back(
new TriggerNode("medium aoe", NextAction::array(0, new NextAction("howling blast", ACTION_HIGH + 4), nullptr)));
new TriggerNode(
"medium aoe",
{
NextAction("howling blast", ACTION_HIGH + 4)
}
)
);
}