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/internal/parser/parser.go

@@ -0,0 +1,141 @@
+package parser
+
+import (
+	"bytes"
+	"strconv"
+
+	"github.com/uptrace/bun/internal"
+)
+
+type Parser struct {
+	b []byte
+	i int
+}
+
+func New(b []byte) *Parser {
+	return &Parser{
+		b: b,
+	}
+}
+
+func NewString(s string) *Parser {
+	return New(internal.Bytes(s))
+}
+
+func (p *Parser) Valid() bool {
+	return p.i < len(p.b)
+}
+
+func (p *Parser) Bytes() []byte {
+	return p.b[p.i:]
+}
+
+func (p *Parser) Read() byte {
+	if p.Valid() {
+		c := p.b[p.i]
+		p.Advance()
+		return c
+	}
+	return 0
+}
+
+func (p *Parser) Peek() byte {
+	if p.Valid() {
+		return p.b[p.i]
+	}
+	return 0
+}
+
+func (p *Parser) Advance() {
+	p.i++
+}
+
+func (p *Parser) Skip(skip byte) bool {
+	if p.Peek() == skip {
+		p.Advance()
+		return true
+	}
+	return false
+}
+
+func (p *Parser) SkipBytes(skip []byte) bool {
+	if len(skip) > len(p.b[p.i:]) {
+		return false
+	}
+	if !bytes.Equal(p.b[p.i:p.i+len(skip)], skip) {
+		return false
+	}
+	p.i += len(skip)
+	return true
+}
+
+func (p *Parser) ReadSep(sep byte) ([]byte, bool) {
+	ind := bytes.IndexByte(p.b[p.i:], sep)
+	if ind == -1 {
+		b := p.b[p.i:]
+		p.i = len(p.b)
+		return b, false
+	}
+
+	b := p.b[p.i : p.i+ind]
+	p.i += ind + 1
+	return b, true
+}
+
+func (p *Parser) ReadIdentifier() (string, bool) {
+	if p.i < len(p.b) && p.b[p.i] == '(' {
+		s := p.i + 1
+		if ind := bytes.IndexByte(p.b[s:], ')'); ind != -1 {
+			b := p.b[s : s+ind]
+			p.i = s + ind + 1
+			return internal.String(b), false
+		}
+	}
+
+	ind := len(p.b) - p.i
+	var alpha bool
+	for i, c := range p.b[p.i:] {
+		if isNum(c) {
+			continue
+		}
+		if isAlpha(c) || (i > 0 && alpha && c == '_') {
+			alpha = true
+			continue
+		}
+		ind = i
+		break
+	}
+	if ind == 0 {
+		return "", false
+	}
+	b := p.b[p.i : p.i+ind]
+	p.i += ind
+	return internal.String(b), !alpha
+}
+
+func (p *Parser) ReadNumber() int {
+	ind := len(p.b) - p.i
+	for i, c := range p.b[p.i:] {
+		if !isNum(c) {
+			ind = i
+			break
+		}
+	}
+	if ind == 0 {
+		return 0
+	}
+	n, err := strconv.Atoi(string(p.b[p.i : p.i+ind]))
+	if err != nil {
+		panic(err)
+	}
+	p.i += ind
+	return n
+}
+
+func isNum(c byte) bool {
+	return c >= '0' && c <= '9'
+}
+
+func isAlpha(c byte) bool {
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
+}