private Expression ForProperty(Expression cur, MemberInfo property)
{
cur = property.ValueFromExpression(cur);
var variable = Expression.Variable(PathBuilderHelper.GetMemberType(property));
m_variables.Add(variable);
m_block.Add(variable);
m_block.Add(Expression.Assign(variable, cur));
cur = variable;
return(cur);
}
Expression ForArray(Expression cur, Type arrayType, ParameterExpression arrayIndexesParam, int arrayIndexNum)
{
var getIndex = PathBuilderHelper.GetIndexExpression(arrayIndexesParam, arrayIndexNum, arrayType);
cur = Expression.Convert(cur, arrayType);
cur = Expression.MakeIndex(cur, arrayType.GetProperty("Item"), new[] { getIndex });
var variable = Expression.Variable(cur.Type);
m_variables.Add(variable);
m_block.Add(variable);
m_block.Add(Expression.Assign(variable, cur));
cur = variable;
return(cur);
}
private Expression ForArray(Expression cur, Type tArr, ParameterExpression indexPar, int indexNum)
{
var indexLeng = Expression.PropertyOrField(indexPar, nameof(Array.Length));
Expression keys;
if (tArr.Name == "IDictionary`2")
{
keys = Expression.PropertyOrField(cur, "Keys");
}
else
{
var countKeys = Expression.PropertyOrField(Expression.Convert(cur, typeof(System.Collections.ICollection)), nameof(System.Collections.ICollection.Count));
keys = Expression.Call(s_rangeEnum, Expression.Constant(0), countKeys);
}
keys = Expression.Call(s_castKeys, keys);
keys = Expression.Call(s_toArrayKeys, keys);
m_block.Add(Expression.IfThen(
Expression.LessThanOrEqual(indexLeng, Expression.Constant(indexNum)),
Expression.Return(m_returnLabel, keys)));
var getIndex = PathBuilderHelper.GetIndexExpression(indexPar, indexNum, tArr);
cur = Expression.MakeIndex(cur, tArr.GetProperty("Item"), new[] { getIndex });
var arrVariable = Expression.Variable(cur.Type);
m_block.Add(Expression.Assign(arrVariable, cur));
m_variables.Add(arrVariable);
m_block.Add(arrVariable);
cur = arrVariable;
return(cur);
}
public static Expression GetFunctionExpression(ParameterExpression sourcePar, ParameterExpression indexesPar, List <PathItem> pathItems)
{
int indexNum = 0;
Expression cur = sourcePar;
foreach (var t in pathItems)
{
if (t.Property != null)
{
cur = t.Property.ValueFromExpression(cur);
}
else if (t.Array != null)
{
Expression getIndex = PathBuilderHelper.GetIndexExpression(indexesPar, indexNum, t.Array);
cur = Expression.Convert(cur, t.Array);
cur = Expression.MakeIndex(cur, t.Array.GetProperty("Item"), new[] { getIndex });
indexNum++;
}
}
return(cur);
}