fix: infer Nullable/Array/LowCardinality with reflection

helps re #152

proto/cmd/ch-gen-col/infer.go.tmpl

@@ -6,10 +6,6 @@ package proto
 func inferGenerated(t ColumnType) Column {
 	switch t {
 	{{- range . }}
-	case ColumnTypeArray.Sub({{ .ColumnType }}):
-		return new({{ .Type }}).Array()
-	case ColumnTypeNullable.Sub({{ .ColumnType }}):
-		return new({{ .Type }}).Nullable()
 	case {{ .ColumnType }}:
 		return new({{ .Type }})
 	{{- end }}

proto/col_auto.go

@@ -1,6 +1,7 @@
 package proto
 
 import (
+	"reflect"
 	"strings"
 
 	"github.com/go-faster/errors"
@@ -36,20 +37,8 @@ func (c *ColAuto) Infer(t ColumnType) error {
 	switch t {
 	case ColumnTypeNothing:
 		c.Data = new(ColNothing)
-	case ColumnTypeNullable.Sub(ColumnTypeNothing):
-		c.Data = new(ColNothing).Nullable()
-	case ColumnTypeArray.Sub(ColumnTypeNothing):
-		c.Data = new(ColNothing).Array()
 	case ColumnTypeString:
 		c.Data = new(ColStr)
-	case ColumnTypeArray.Sub(ColumnTypeString):
-		c.Data = new(ColStr).Array()
-	case ColumnTypeNullable.Sub(ColumnTypeString):
-		c.Data = new(ColStr).Nullable()
-	case ColumnTypeLowCardinality.Sub(ColumnTypeString):
-		c.Data = new(ColStr).LowCardinality()
-	case ColumnTypeArray.Sub(ColumnTypeLowCardinality.Sub(ColumnTypeString)):
-		c.Data = new(ColStr).LowCardinality().Array()
 	case ColumnTypeBool:
 		c.Data = new(ColBool)
 	case ColumnTypeDateTime:
@@ -60,12 +49,44 @@ func (c *ColAuto) Infer(t ColumnType) error {
 		c.Data = NewMap[string, string](new(ColStr), new(ColStr))
 	case ColumnTypeUUID:
 		c.Data = new(ColUUID)
-	case ColumnTypeArray.Sub(ColumnTypeUUID):
-		c.Data = new(ColUUID).Array()
-	case ColumnTypeNullable.Sub(ColumnTypeUUID):
-		c.Data = new(ColUUID).Nullable()
 	default:
 		switch t.Base() {
+		case ColumnTypeArray:
+			inner := new(ColAuto)
+			inner.Infer(ColumnType(t.Elem()))
+			innerValue := reflect.ValueOf(inner.Data)
+			arrayMethod := innerValue.MethodByName("Array")
+			if arrayMethod.IsValid() && arrayMethod.Type().NumOut() == 1 {
+				if col, ok := arrayMethod.Call(nil)[0].Interface().(Column); ok {
+					c.Data = col
+					c.DataType = t
+					return nil
+				}
+			}
+		case ColumnTypeNullable:
+			inner := new(ColAuto)
+			inner.Infer(ColumnType(t.Elem()))
+			innerValue := reflect.ValueOf(inner.Data)
+			nullableMethod := innerValue.MethodByName("Nullable")
+			if nullableMethod.IsValid() && nullableMethod.Type().NumOut() == 1 {
+				if col, ok := nullableMethod.Call(nil)[0].Interface().(Column); ok {
+					c.Data = col
+					c.DataType = t
+					return nil
+				}
+			}
+		case ColumnTypeLowCardinality:
+			inner := new(ColAuto)
+			inner.Infer(ColumnType(t.Elem()))
+			innerValue := reflect.ValueOf(inner.Data)
+			lowCardinalityMethod := innerValue.MethodByName("LowCardinality")
+			if lowCardinalityMethod.IsValid() && lowCardinalityMethod.Type().NumOut() == 1 {
+				if col, ok := lowCardinalityMethod.Call(nil)[0].Interface().(Column); ok {
+					c.Data = col
+					c.DataType = t
+					return nil
+				}
+			}
 		case ColumnTypeDateTime:
 			v := new(ColDateTime)
 			if err := v.Infer(t); err != nil {