feat: expose the lexer to be used by users

pkg/lexer/lexer.go

@@ -0,0 +1,28 @@
+package lexer
+
+import (
+	"errors"
+
+	"github.com/laytan/php-parser/internal/php7"
+	"github.com/laytan/php-parser/internal/php8"
+	"github.com/laytan/php-parser/pkg/conf"
+	"github.com/laytan/php-parser/pkg/token"
+)
+
+var ErrVersionOutOfRange = errors.New("the version is out of supported range")
+
+type Lexer interface {
+	Lex() *token.Token
+}
+
+func New(src []byte, config conf.Config) (Lexer, error) {
+	if config.Version.InPhp7Range() {
+		return php7.NewLexer(src, config), nil
+	}
+
+	if config.Version.InPhp8Range() {
+		return php8.NewLexer(src, config), nil
+	}
+
+	return nil, ErrVersionOutOfRange
+}