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/dialect/pgdialect/array_parser.go

@@ -0,0 +1,146 @@
+package pgdialect
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+type arrayParser struct {
+	b []byte
+	i int
+
+	buf []byte
+	err error
+}
+
+func newArrayParser(b []byte) *arrayParser {
+	p := &arrayParser{
+		b: b,
+		i: 1,
+	}
+	if len(b) < 2 || b[0] != '{' || b[len(b)-1] != '}' {
+		p.err = fmt.Errorf("bun: can't parse array: %q", b)
+	}
+	return p
+}
+
+func (p *arrayParser) NextElem() ([]byte, error) {
+	if p.err != nil {
+		return nil, p.err
+	}
+
+	c, err := p.readByte()
+	if err != nil {
+		return nil, err
+	}
+
+	switch c {
+	case '}':
+		return nil, io.EOF
+	case '"':
+		b, err := p.readSubstring()
+		if err != nil {
+			return nil, err
+		}
+
+		if p.peek() == ',' {
+			p.skipNext()
+		}
+
+		return b, nil
+	default:
+		b := p.readSimple()
+		if bytes.Equal(b, []byte("NULL")) {
+			b = nil
+		}
+
+		if p.peek() == ',' {
+			p.skipNext()
+		}
+
+		return b, nil
+	}
+}
+
+func (p *arrayParser) readSimple() []byte {
+	p.unreadByte()
+
+	if i := bytes.IndexByte(p.b[p.i:], ','); i >= 0 {
+		b := p.b[p.i : p.i+i]
+		p.i += i
+		return b
+	}
+
+	b := p.b[p.i : len(p.b)-1]
+	p.i = len(p.b) - 1
+	return b
+}
+
+func (p *arrayParser) readSubstring() ([]byte, error) {
+	c, err := p.readByte()
+	if err != nil {
+		return nil, err
+	}
+
+	p.buf = p.buf[:0]
+	for {
+		if c == '"' {
+			break
+		}
+
+		next, err := p.readByte()
+		if err != nil {
+			return nil, err
+		}
+
+		if c == '\\' {
+			switch next {
+			case '\\', '"':
+				p.buf = append(p.buf, next)
+
+				c, err = p.readByte()
+				if err != nil {
+					return nil, err
+				}
+			default:
+				p.buf = append(p.buf, '\\')
+				c = next
+			}
+			continue
+		}
+
+		p.buf = append(p.buf, c)
+		c = next
+	}
+
+	return p.buf, nil
+}
+
+func (p *arrayParser) valid() bool {
+	return p.i < len(p.b)
+}
+
+func (p *arrayParser) readByte() (byte, error) {
+	if p.valid() {
+		c := p.b[p.i]
+		p.i++
+		return c, nil
+	}
+	return 0, io.EOF
+}
+
+func (p *arrayParser) unreadByte() {
+	p.i--
+}
+
+func (p *arrayParser) peek() byte {
+	if p.valid() {
+		return p.b[p.i]
+	}
+	return 0
+}
+
+func (p *arrayParser) skipNext() {
+	p.i++
+}