implementing feedback

literals.go

@@ -467,8 +467,7 @@ func (t TimestampLiteral) To(typ Type) (Literal, error) {
  case TimestampTzType:
  return t, nil
  case DateType:
- tm := time.UnixMicro(int64(t)).UTC()
- return DateLiteral(tm.Truncate(24*time.Hour).Unix() / int64((time.Hour * 24).Seconds())), nil
+ return DateLiteral(Timestamp(t).ToDate()), nil
  }
  return nil, fmt.Errorf("%w: TimestampLiteral to %s", ErrBadCast, typ)
 }
@@ -538,19 +537,23 @@ func (s StringLiteral) To(typ Type) (Literal, error) {
 
  return TimeLiteral(val), nil
  case TimestampType:
- val, err := arrow.TimestampFromString(string(s), arrow.Microsecond)
+ // requires RFC3339 with no time zone
+ tm, err := time.Parse("2006-01-02T15:04:05", string(s))
  if err != nil {
- return nil, fmt.Errorf("%w: casting '%s' to %s - %s",
- ErrBadCast, s, typ, err.Error())
+ return nil, fmt.Errorf("%w: invalid Timestamp format for casting from string '%s': %s",
+ ErrBadCast, s, err.Error())
  }
- return TimestampLiteral(val), nil
+
+ return TimestampLiteral(Timestamp(tm.UTC().UnixMicro())), nil
  case TimestampTzType:
- val, err := arrow.TimestampFromString(string(s), arrow.Microsecond)
+ // requires RFC3339 format WITH time zone
+ tm, err := time.Parse(time.RFC3339, string(s))
  if err != nil {
- return nil, fmt.Errorf("%w: casting '%s' to %s - %s",
- ErrBadCast, s, typ, err.Error())
+ return nil, fmt.Errorf("%w: invalid TimestampTz format for casting from string '%s': %s",
+ ErrBadCast, s, err.Error())
  }
- return TimestampLiteral(val), nil
+
+ return TimestampLiteral(Timestamp(tm.UTC().UnixMicro())), nil
  case UUIDType:
  val, err := uuid.Parse(string(s))
  if err != nil {

literals_test.go

@@ -358,12 +358,8 @@ func TestStringLiteralConversion(t *testing.T) {
  iceberg.NewLiteral(iceberg.Date(arrow.Date32FromTime(tm)))},
  {iceberg.StringLiteral("14:21:01.919"),
  iceberg.NewLiteral(iceberg.Time(51661919000))},
- {iceberg.StringLiteral("2017-08-18T14:21:01.919234+00:00"),
- iceberg.NewLiteral(iceberg.Timestamp(1503066061919234))},
  {iceberg.StringLiteral("2017-08-18T14:21:01.919234"),
  iceberg.NewLiteral(iceberg.Timestamp(1503066061919234))},
- {iceberg.StringLiteral("2017-08-18T14:21:01.919234-07:00"),
- iceberg.NewLiteral(iceberg.Timestamp(1503091261919234))},
  {iceberg.StringLiteral(expected.String()), iceberg.NewLiteral(expected)},
  {iceberg.StringLiteral("34.560"),
  iceberg.NewLiteral(iceberg.Decimal{Val: decimal128.FromI64(34560), Scale: 3})},
@@ -383,6 +379,24 @@ func TestStringLiteralConversion(t *testing.T) {
  assert.Truef(t, tt.to.Equals(got), "expected: %s, got: %s", tt.to, got)
  })
  }
+
+ lit := iceberg.StringLiteral("2017-08-18T14:21:01.919234-07:00")
+ casted, err := lit.To(iceberg.PrimitiveTypes.TimestampTz)
+ require.NoError(t, err)
+ expectedTimestamp := iceberg.NewLiteral(iceberg.Timestamp(1503091261919234))
+ assert.Truef(t, casted.Equals(expectedTimestamp), "expected: %s, got: %s",
+ expectedTimestamp, casted)
+
+ _, err = lit.To(iceberg.PrimitiveTypes.Timestamp)
+ require.Error(t, err)
+ assert.ErrorIs(t, err, iceberg.ErrBadCast)
+ assert.ErrorContains(t, err, `parsing time "2017-08-18T14:21:01.919234-07:00": extra text: "-07:00"`)
+ assert.ErrorContains(t, err, "invalid Timestamp format for casting from string")
+
+ _, err = iceberg.StringLiteral("2017-08-18T14:21:01.919234").To(iceberg.PrimitiveTypes.TimestampTz)
+ require.Error(t, err)
+ assert.ErrorIs(t, err, iceberg.ErrBadCast)
+ assert.ErrorContains(t, err, `cannot parse "" as "Z07:00"`)
 }
 
 func TestLiteralIdentityConversions(t *testing.T) {

types.go

@@ -23,6 +23,7 @@ import (
  "regexp"
  "strconv"
  "strings"
+ "time"
 
  "github.com/apache/arrow/go/v16/arrow/decimal128"
  "golang.org/x/exp/slices"
@@ -535,6 +536,11 @@ func (TimeType) String() string { return "time" }
 
 type Timestamp int64
 
+func (t Timestamp) ToDate() Date {
+ tm := time.UnixMicro(int64(t)).UTC()
+ return Date(tm.Truncate(24*time.Hour).Unix() / int64((time.Hour * 24).Seconds()))
+}
+
 // TimestampType represents a number of microseconds since the unix epoch
 // without regard for timezone.
 type TimestampType struct{}