Pg to bun (#148)

* start moving to bun

* changing more stuff

* more

* and yet more

* tests passing

* seems stable now

* more big changes

* small fix

* little fixes

vendor/github.com/uptrace/bun/util.go

@@ -0,0 +1,114 @@
+package bun
+
+import "reflect"
+
+func indirect(v reflect.Value) reflect.Value {
+	switch v.Kind() {
+	case reflect.Interface:
+		return indirect(v.Elem())
+	case reflect.Ptr:
+		return v.Elem()
+	default:
+		return v
+	}
+}
+
+func walk(v reflect.Value, index []int, fn func(reflect.Value)) {
+	v = reflect.Indirect(v)
+	switch v.Kind() {
+	case reflect.Slice:
+		sliceLen := v.Len()
+		for i := 0; i < sliceLen; i++ {
+			visitField(v.Index(i), index, fn)
+		}
+	default:
+		visitField(v, index, fn)
+	}
+}
+
+func visitField(v reflect.Value, index []int, fn func(reflect.Value)) {
+	v = reflect.Indirect(v)
+	if len(index) > 0 {
+		v = v.Field(index[0])
+		if v.Kind() == reflect.Ptr && v.IsNil() {
+			return
+		}
+		walk(v, index[1:], fn)
+	} else {
+		fn(v)
+	}
+}
+
+func typeByIndex(t reflect.Type, index []int) reflect.Type {
+	for _, x := range index {
+		switch t.Kind() {
+		case reflect.Ptr:
+			t = t.Elem()
+		case reflect.Slice:
+			t = indirectType(t.Elem())
+		}
+		t = t.Field(x).Type
+	}
+	return indirectType(t)
+}
+
+func indirectType(t reflect.Type) reflect.Type {
+	if t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	return t
+}
+
+func sliceElemType(v reflect.Value) reflect.Type {
+	elemType := v.Type().Elem()
+	if elemType.Kind() == reflect.Interface && v.Len() > 0 {
+		return indirect(v.Index(0).Elem()).Type()
+	}
+	return indirectType(elemType)
+}
+
+func makeSliceNextElemFunc(v reflect.Value) func() reflect.Value {
+	if v.Kind() == reflect.Array {
+		var pos int
+		return func() reflect.Value {
+			v := v.Index(pos)
+			pos++
+			return v
+		}
+	}
+
+	sliceType := v.Type()
+	elemType := sliceType.Elem()
+
+	if elemType.Kind() == reflect.Ptr {
+		elemType = elemType.Elem()
+		return func() reflect.Value {
+			if v.Len() < v.Cap() {
+				v.Set(v.Slice(0, v.Len()+1))
+				elem := v.Index(v.Len() - 1)
+				if elem.IsNil() {
+					elem.Set(reflect.New(elemType))
+				}
+				return elem.Elem()
+			}
+
+			elem := reflect.New(elemType)
+			v.Set(reflect.Append(v, elem))
+			return elem.Elem()
+		}
+	}
+
+	zero := reflect.Zero(elemType)
+	return func() reflect.Value {
+		l := v.Len()
+		c := v.Cap()
+
+		if l < c {
+			v.Set(v.Slice(0, l+1))
+			return v.Index(l)
+		}
+
+		v.Set(reflect.Append(v, zero))
+		return v.Index(l)
+	}
+}