Change max occurs override logic

[veewee]

This PR changes the max occurs override logic for sequences:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:complexType name="complexType">
        <xs:sequence maxOccurs="5" >
            <xs:element name="el1" maxOccurs="3" type="xs:string"></xs:element>
        </xs:sequence>
    </xs:complexType>
</xs:schema>

This actually means the element can have a maximum occurence of 15 instead of the returned 5 for el1.

It even becomes more complex if you add additional elements to the sequence:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:complexType name="complexType">
        <xs:sequence maxOccurs="5" >
            <xs:element name="el1" maxOccurs="3" type="xs:string"></xs:element>
            <xs:element name="el2" maxOccurs="3" type="xs:string"></xs:element>
        </xs:sequence>
    </xs:complexType>
</xs:schema>

Now the availability (or not) of el2 has in impact on the maximum amount of el1's that can be set:

// Sequence1:
<el1>foo</el1>
<el1>foo</el1>
<el2>foo</el1>

// Sequence2:
<el1>foo</el1>
<el2>foo</el1>

Since it obeys the order of elements:

• For sequence 1, the maximum for el1 is now at 2.
• For sequence 2, the maximum for el1 is now at 1.
• ...

It becomes even more complex once nexted choices get introduced:
(this was not supported yet, but got introduced in this PR as well)

<xs:schema targetNamespace="http://www.example.com" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:complexType name="complexType">
        <xs:sequence maxOccurs="2" >
            <xs:choice maxOccurs="2">
                <xs:element name="el1" maxOccurs="3" type="xs:string"></xs:element>
                <xs:element name="el2" maxOccurs="3" type="xs:string"></xs:element>
            </xs:choice>
        </xs:sequence>
    </xs:complexType>
</xs:schema>

Now both the sequence count, choice count and element occurence count have an impact on the maximum amount of elements.

Since this is all becoming way too complex and unreliable, I suggest to set the maximum occurences to -1 instead (which means you can have many elements).
For code generation, this should result in an array anyways.

More context:
phpro/soap-client#540

[goetas]

Makes sense, thank you