More pluggable value transcoding

data_row_reader.go

@@ -1,13 +1,9 @@
 package pgx
 
-import (
-	"fmt"
-	"strconv"
-)
-
 type DataRowReader struct {
-	mr     *MessageReader
-	fields []FieldDescription
+	mr              *MessageReader
+	fields          []FieldDescription
+	currentFieldIdx int
 }
 
 func newDataRowReader(mr *MessageReader, fields []FieldDescription) (r *DataRowReader) {
@@ -24,55 +20,14 @@ func newDataRowReader(mr *MessageReader, fields []FieldDescription) (r *DataRowR
 }
 
 func (r *DataRowReader) ReadValue() interface{} {
+	dataType := r.fields[r.currentFieldIdx].DataType
+	r.currentFieldIdx++
+
 	size := r.mr.ReadInt32()
 	if size > -1 {
-		switch r.fields[0].DataType {
-		case oid(16): // bool
-			s := r.mr.ReadByteString(size)
-			switch s {
-			case "t":
-				return true
-			case "f":
-				return false
-			default:
-				panic(fmt.Sprintf("Received invalid bool: %v", s))
-			}
-		case oid(20): // int8
-			s := r.mr.ReadByteString(size)
-			n, err := strconv.ParseInt(s, 10, 64)
-			if err != nil {
-				panic(fmt.Sprintf("Received invalid int8: %v", s))
-			}
-			return n
-		case oid(21): // int2
-			s := r.mr.ReadByteString(size)
-			n, err := strconv.ParseInt(s, 10, 16)
-			if err != nil {
-				panic(fmt.Sprintf("Received invalid int2: %v", s))
-			}
-			return int16(n)
-		case oid(23): // int4
-			s := r.mr.ReadByteString(size)
-			n, err := strconv.ParseInt(s, 10, 32)
-			if err != nil {
-				panic(fmt.Sprintf("Received invalid int4: %v", s))
-			}
-			return int32(n)
-		case oid(700): // float4
-			s := r.mr.ReadByteString(size)
-			n, err := strconv.ParseFloat(s, 32)
-			if err != nil {
-				panic(fmt.Sprintf("Received invalid float4: %v", s))
-			}
-			return float32(n)
-		case oid(701): //float8
-			s := r.mr.ReadByteString(size)
-			v, err := strconv.ParseFloat(s, 64)
-			if err != nil {
-				panic(fmt.Sprintf("Received invalid float8: %v", s))
-			}
-			return v
-		default:
+		if vt, present := valueTranscoders[dataType]; present {
+			return vt.FromText(r.mr, size)
+		} else {
 			return r.mr.ReadByteString(size)
 		}
 	} else {