simplify some types of union

xsdgen/testdata/redundant-union.go.golden

@@ -0,0 +1,18 @@
+// Code generated by xsdgen.test. DO NOT EDIT.
+
+package ws
+
+import "encoding/xml"
+
+// May be one of A, B, C
+type EnumType string
+
+const (
+ EnumType_A EnumType = "A"
+ EnumType_B EnumType = "B"
+ EnumType_C EnumType = "C"
+)
+
+type Type1 struct {
+ Elem []EnumType `xml:"Elem,omitempty"`
+}

xsdgen/testdata/redundant-union.xsd

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- edited with XMLSpy v2008 (http://www.altova.com) by A (A) -->
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+ xmlns="http://example.org/" targetNamespace="http://example.org/">
+ <xs:element name="Type1">
+ <xs:complexType>
+ <xs:sequence minOccurs="1" maxOccurs="1">
+ <xs:element name="Elem" type="redundantUnionType" minOccurs="0" maxOccurs="unbounded"/>
+ </xs:sequence>
+ </xs:complexType>
+ </xs:element>
+
+ <xs:simpleType name="enumType">
+ <xs:restriction base="xs:string">
+ <xs:enumeration value="A"/>
+ <xs:enumeration value="B"/>
+ <xs:enumeration value="C"/>
+ </xs:restriction>
+ </xs:simpleType>
+
+ <xs:simpleType name="redundantUnionType">
+ <xs:union memberTypes="enumType xs:string"/>
+ </xs:simpleType>
+
+</xs:schema>

xsdgen/xsdgen.go

@@ -402,6 +402,54 @@ func dedup(types []xsd.Type) (unique []xsd.Type) {
  return unique
 }
 
+// for now, bustUnion only resolves simple cases like a union of a builtin and an enum of the same builtin, e.g. in
+// this case redundantUnionType will be replaced with enumType
+//
+// <xs:simpleType name="enumType">
+// <xs:restriction base="xs:string">
+// <xs:enumeration value="A"/>
+// <xs:enumeration value="B"/>
+// </xs:restriction>
+// </xs:simpleType>
+//
+// <xs:simpleType name="redundantUnionType">
+// <xs:union memberTypes="enumType xs:string"/>
+// </xs:simpleType>
+func (cfg *Config) bustUnion(t *xsd.SimpleType) xsd.Type {
+ var underlying xsd.Type
+ var actual xsd.Type
+ for _, member := range t.Union {
+ switch ut := member.(type) {
+ case xsd.Builtin:
+ if underlying != nil && underlying != ut {
+ // can't simplify
+ return t
+ }
+ underlying = ut
+ case *xsd.SimpleType:
+ base := xsd.Base(ut)
+ if underlying != nil && underlying != ut {
+ // can't simplify
+ return t
+ }
+ if actual != nil && actual != ut {
+ // TODO: can we simplify this case?
+ return t
+ }
+ underlying = base
+ actual = ut
+ default:
+ // TODO: handle more union member types
+ return t
+ }
+ }
+
+ if actual != nil {
+ return actual
+ }
+ return underlying
+}
+
 func (cfg *Config) flatten1(t xsd.Type, push func(xsd.Type), depth int) xsd.Type {
  const maxDepth = 1000
  if depth > maxDepth {
@@ -414,7 +462,12 @@ func (cfg *Config) flatten1(t xsd.Type, push func(xsd.Type), depth int) xsd.Type
  base, builtin xsd.Type
  ok bool
  )
- // TODO: handle list/union types
+ // TODO: handle list types
+
+ if len(t.Union) > 0 {
+ return cfg.bustUnion(t)
+ }
+
  for base = xsd.Base(t); base != nil; base = xsd.Base(base) {
  if builtin, ok = base.(xsd.Builtin); ok {
  break