pkg/ast: introduce hex-encoded string literals

The stringnozescapes does not make sense with filename,
also we may need similar escaping for string flags.
Handle escaped strings on ast level instead.
This avoids introducing new type and works seamleassly with flags.

As alternative I've also tried using strconv.Quote/Unquote
but it leads to ugly half-escaped strings:
"\xb0\x80s\xe8\xd4N\x91\xe3ڒ,\"C\x82D\xbb\x88\\i\xe2i\xc8\xe9\xd85\xb1\x14):M\xdcn"

Make hex-encoded strings a separate string format instead.

1 files changed, 16 insertions, 3 deletions

diff --git a/pkg/ast/parser.go b/pkg/ast/parser.go
index b8d22fd88..7b46f6611 100644
--- a/pkg/ast/parser.go
+++ b/pkg/ast/parser.go
@@ -314,7 +314,7 @@ func (p *parser) parseFlags(name *Ident) Node {
 	switch p.tok {
 	case tokInt, tokIdent:
 		return p.parseIntFlags(name)
-	case tokString:
+	case tokString, tokStringHex:
 		return p.parseStrFlags(name)
 	default:
 		p.expect(tokInt, tokIdent, tokString)
@@ -417,9 +417,10 @@ func (p *parser) parseType() *Type {
 	case tokIdent:
 		allowColon = true
 		arg.Ident = p.lit
-	case tokString:
+	case tokString, tokStringHex:
 		arg.String = p.lit
 		arg.HasString = true
+		arg.StringFmt = strTokToFmt(p.tok)
 	default:
 		p.expect(tokInt, tokIdent, tokString)
 	}
@@ -468,15 +469,27 @@ func (p *parser) parseIdent() *Ident {
 }
 
 func (p *parser) parseString() *String {
-	p.expect(tokString)
+	p.expect(tokString, tokStringHex)
 	str := &String{
 		Pos:   p.pos,
 		Value: p.lit,
+		Fmt:   strTokToFmt(p.tok),
 	}
 	p.next()
 	return str
 }
 
+func strTokToFmt(tok token) StrFmt {
+	switch tok {
+	case tokString:
+		return StrFmtRaw
+	case tokStringHex:
+		return StrFmtHex
+	default:
+		panic("bad string token")
+	}
+}
+
 func (p *parser) parseInt() *Int {
 	i := &Int{
 		Pos: p.pos,