Add int4range

range.go

@@ -0,0 +1,273 @@
+package pgtype
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+)
+
+type BoundType byte
+
+const (
+	Inclusive = BoundType('i')
+	Exclusive = BoundType('e')
+	Unbounded = BoundType('U')
+	Empty     = BoundType('E')
+)
+
+type UntypedTextRange struct {
+	Lower     string
+	Upper     string
+	LowerType BoundType
+	UpperType BoundType
+}
+
+func ParseUntypedTextRange(src string) (*UntypedTextRange, error) {
+	utr := &UntypedTextRange{}
+	if src == "empty" {
+		utr.LowerType = 'E'
+		utr.UpperType = 'E'
+		return utr, nil
+	}
+
+	buf := bytes.NewBufferString(src)
+
+	skipWhitespace(buf)
+
+	r, _, err := buf.ReadRune()
+	if err != nil {
+		return nil, fmt.Errorf("invalid lower bound: %v", err)
+	}
+	switch r {
+	case '(':
+		utr.LowerType = Exclusive
+	case '[':
+		utr.LowerType = Inclusive
+	default:
+		return nil, fmt.Errorf("missing lower bound, instead got: %v", string(r))
+	}
+
+	r, _, err = buf.ReadRune()
+	if err != nil {
+		return nil, fmt.Errorf("invalid lower value: %v", err)
+	}
+	buf.UnreadRune()
+
+	if r == ',' {
+		utr.LowerType = Unbounded
+	} else {
+		utr.Lower, err = rangeParseValue(buf)
+		if err != nil {
+			return nil, fmt.Errorf("invalid lower value: %v", err)
+		}
+	}
+
+	r, _, err = buf.ReadRune()
+	if err != nil {
+		return nil, fmt.Errorf("missing range separator: %v", err)
+	}
+	if r != ',' {
+		return nil, fmt.Errorf("missing range separator: %v", r)
+	}
+
+	r, _, err = buf.ReadRune()
+	if err != nil {
+		return nil, fmt.Errorf("invalid upper value: %v", err)
+	}
+	buf.UnreadRune()
+
+	if r == ')' || r == ']' {
+		utr.UpperType = Unbounded
+	} else {
+		utr.Upper, err = rangeParseValue(buf)
+		if err != nil {
+			return nil, fmt.Errorf("invalid upper value: %v", err)
+		}
+	}
+
+	r, _, err = buf.ReadRune()
+	if err != nil {
+		return nil, fmt.Errorf("missing upper bound: %v", err)
+	}
+	switch r {
+	case ')':
+		utr.UpperType = Exclusive
+	case ']':
+		utr.UpperType = Inclusive
+	default:
+		return nil, fmt.Errorf("missing upper bound, instead got: %v", string(r))
+	}
+
+	skipWhitespace(buf)
+
+	if buf.Len() > 0 {
+		return nil, fmt.Errorf("unexpected trailing data: %v", buf.String())
+	}
+
+	return utr, nil
+}
+
+func rangeParseValue(buf *bytes.Buffer) (string, error) {
+	r, _, err := buf.ReadRune()
+	if err != nil {
+		return "", err
+	}
+	if r == '"' {
+		return rangeParseQuotedValue(buf)
+	}
+	buf.UnreadRune()
+
+	s := &bytes.Buffer{}
+
+	for {
+		r, _, err := buf.ReadRune()
+		if err != nil {
+			return "", err
+		}
+
+		switch r {
+		case '\\':
+			r, _, err = buf.ReadRune()
+			if err != nil {
+				return "", err
+			}
+		case ',', '[', ']', '(', ')':
+			buf.UnreadRune()
+			return s.String(), nil
+		}
+
+		s.WriteRune(r)
+	}
+}
+
+func rangeParseQuotedValue(buf *bytes.Buffer) (string, error) {
+	s := &bytes.Buffer{}
+
+	for {
+		r, _, err := buf.ReadRune()
+		if err != nil {
+			return "", err
+		}
+
+		switch r {
+		case '\\':
+			r, _, err = buf.ReadRune()
+			if err != nil {
+				return "", err
+			}
+		case '"':
+			r, _, err = buf.ReadRune()
+			if err != nil {
+				return "", err
+			}
+			if r != '"' {
+				buf.UnreadRune()
+				return s.String(), nil
+			}
+		}
+		s.WriteRune(r)
+	}
+}
+
+type UntypedBinaryRange struct {
+	Lower     []byte
+	Upper     []byte
+	LowerType BoundType
+	UpperType BoundType
+}
+
+// 0 = ()      = 00000
+// 1 = empty   = 00001
+// 2 = [)      = 00010
+// 4 = (]      = 00100
+// 6 = []      = 00110
+// 8 = )       = 01000
+// 12 = ]      = 01100
+// 16 = (      = 10000
+// 18 = [      = 10010
+// 24 =        = 11000
+
+const emptyMask = 1
+const lowerInclusiveMask = 2
+const upperInclusiveMask = 4
+const lowerUnboundedMask = 8
+const upperUnboundedMask = 16
+
+func ParseUntypedBinaryRange(src []byte) (*UntypedBinaryRange, error) {
+	ubr := &UntypedBinaryRange{}
+
+	if len(src) == 0 {
+		return nil, fmt.Errorf("range too short: %v", len(src))
+	}
+
+	rangeType := src[0]
+	rp := 1
+
+	if rangeType&emptyMask > 0 {
+		if len(src[rp:]) > 0 {
+			return nil, fmt.Errorf("unexpected trailing bytes parsing empty range: %v", len(src[rp:]))
+		}
+		ubr.LowerType = Empty
+		ubr.UpperType = Empty
+		return ubr, nil
+	}
+
+	if rangeType&lowerInclusiveMask > 0 {
+		ubr.LowerType = Inclusive
+	} else if rangeType&lowerUnboundedMask > 0 {
+		ubr.LowerType = Unbounded
+	} else {
+		ubr.LowerType = Exclusive
+	}
+
+	if rangeType&upperInclusiveMask > 0 {
+		ubr.UpperType = Inclusive
+	} else if rangeType&upperUnboundedMask > 0 {
+		ubr.UpperType = Unbounded
+	} else {
+		ubr.UpperType = Exclusive
+	}
+
+	if ubr.LowerType == Unbounded && ubr.UpperType == Unbounded {
+		if len(src[rp:]) > 0 {
+			return nil, fmt.Errorf("unexpected trailing bytes parsing unbounded range: %v", len(src[rp:]))
+		}
+		return ubr, nil
+	}
+
+	if len(src[rp:]) < 4 {
+		return nil, fmt.Errorf("too few bytes for size: %v", src[rp:])
+	}
+	valueLen := int(binary.BigEndian.Uint32(src[rp:]))
+	rp += 4
+
+	val := src[rp : rp+valueLen]
+	rp += valueLen
+
+	if ubr.LowerType != Unbounded {
+		ubr.Lower = val
+	} else {
+		ubr.Upper = val
+		if len(src[rp:]) > 0 {
+			return nil, fmt.Errorf("unexpected trailing bytes parsing range: %v", len(src[rp:]))
+		}
+		return ubr, nil
+	}
+
+	if ubr.UpperType != Unbounded {
+		if len(src[rp:]) < 4 {
+			return nil, fmt.Errorf("too few bytes for size: %v", src[rp:])
+		}
+		valueLen := int(binary.BigEndian.Uint32(src[rp:]))
+		rp += 4
+		ubr.Upper = src[rp : rp+valueLen]
+		rp += valueLen
+	}
+
+	if len(src[rp:]) > 0 {
+		return nil, fmt.Errorf("unexpected trailing bytes parsing range: %v", len(src[rp:]))
+	}
+
+	return ubr, nil
+
+}