/** Builds a FGameplayTagQueryExpression from this query. */
public void GetQueryExpr(CGameplayTagQueryExpression OutExpr)
{
//根据传入的steam token创建表达式树
FQueryEvaluator QE = new FQueryEvaluator(this);
QE.Read(OutExpr);
}
/** 创建一个query */
public static FGameplayTagQuery BuildQuery(CGameplayTagQueryExpression RootQueryExpr, string InDescription = "")
{
FGameplayTagQuery Q = new FGameplayTagQuery();
Q.Build(RootQueryExpr, InDescription);
return(Q);
}
/** 创建查询byte数据, 根据传入的查询表达式. */
public void Build(CGameplayTagQueryExpression RootQueryExpr, string InUserDescription)
{
UserDescription = InUserDescription;
QueryTokenStream.Clear();
TagDictionary.Clear();
// emit the query
QueryTokenStream.Add(1); // true to indicate is has a root expression
RootQueryExpr.EmitTokens(QueryTokenStream, TagDictionary);
}
private void ReadExpr(CGameplayTagQueryExpression E)
{
E.ExprType = (CGameplayTagQueryExprType)GetToken();
if (bReadError)
{
return;
}
if (E.UsesTagSet())
{
// parse tag set
byte NumTags = GetToken();
if (bReadError)
{
return;
}
for (byte Idx = 0; Idx < NumTags; ++Idx)
{
byte TagIdx = GetToken();
if (bReadError)
{
return;
}
CGameplayTag Tag = Query.GetTagFromIndex(TagIdx);
E.AddTag(Tag);
}
}
else
{
// parse expr set
byte NumExprs = GetToken();
if (bReadError)
{
return;
}
for (byte Idx = 0; Idx < NumExprs; ++Idx)
{
CGameplayTagQueryExpression Exp = new CGameplayTagQueryExpression();
ReadExpr(Exp);
Exp.AddExpr(Exp);
}
}
}
/** 解析 the token stream 数据 传入到 FGameplayTagQueryExpression. */
public void Read(CGameplayTagQueryExpression E)
{
CurStreamIdx = 0;
if (Query.IsEmpty())
{
return;
}
// start parsing the set
if (!bReadError)
{
bool bHasRootExpression = GetToken() != 0;
if (!bReadError && bHasRootExpression)
{
ReadExpr(E);
}
}
}
public CGameplayTagQueryExpression AddExpr(CGameplayTagQueryExpression Expr)
{
ExprSet.Add(Expr);
return(this);
}
/**
* 创建 有完全没有tag匹配的查询
*/
public static FGameplayTagQuery MakeQuery_MatchNoTags(CGameplayTagContainer InTags)
{
var qe = new CGameplayTagQueryExpression();
return(BuildQuery(qe.NoTagsMatch().AddTags(InTags)));
}
