Feature #3619: \x{XXXX} as an escape sequence of string - Ruby master - Ruby Issue Tracking System

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Feature #3619

closed

\x{XXXX} as an escape sequence of string

Added by phasis68 (Heesob Park) over 14 years ago. Updated over 12 years ago.

Status:

Rejected

Assignee:

Target version:

2.0.0

[ruby-core:31512]

Description

=begin
I noticed String#inspect results \x{XXXX} for the encoding other than Unicode.

Is there any possibility that \x{XXXX} is accepted as an escape sequence of string?

irb(main):004:0> a = "\xC7\xD1\xB1\xDB"
=> "\xC7ѱ\xDB"
irb(main):005:0> a.encoding
=> #Encoding:UTF-8
irb(main):006:0> a.force_encoding('EUC-KR')
=> "\x{C7D1}\x{B1DB}"
irb(main):007:0> a.encode('UTF-8')
=> "한글"
irb(main):008:0> a
=> "\x{C7D1}\x{B1DB}"
irb(main):009:0> a[0]
=> "\x{C7D1}"
irb(main):010:0> a[1]
=> "\x{B1DB}"
irb(main):011:0> b = "\x{B1DB}"
SyntaxError: (irb):11: invalid hex escape
b = "\x{B1DB}"
^
from /usr/local/bin/irb:12:in `'
=end

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Updated by nobu (Nobuyoshi Nakada) over 14 years ago

=begin
Hi,

At Tue, 27 Jul 2010 22:21:31 +0900,
Heesob Park wrote in [ruby-core:31512]:

I noticed String#inspect results \x{XXXX} for the encoding other than Unicode.

Is there any possibility that \x{XXXX} is accepted as an escape sequence of string?

irb(main):004:0> a = "\xC7\xD1\xB1\xDB"

This is in binary representation.

irb(main):010:0> a[1]
=> "\x{B1DB}"

But this is in codepoint representation.

I'm afraid it may confuse users.

diff --git a/parse.y b/parse.y
index ba52135..ec13fb6 100644
--- a/parse.y
+++ b/parse.y
@@ -5456,8 +5456,8 @@ parser_tok_hex(struct parser_params *parser, size_t *numlen)
#define tokcopy(n) memcpy(tokspace(n), lex_p - (n), (n))

static int
-parser_tokadd_utf8(struct parser_params *parser, rb_encoding **encp,

              int string_literal, int symbol_literal, int regexp_literal)

+parser_tokadd_multibyte(struct parser_params *parser, rb_encoding **encp, int enctype,

 	int string_literal, int symbol_literal, int regexp_literal)

{
/*
* If string_literal is true, then we allow multiple codepoints
@@ -5466,22 +5466,28 @@ parser_tokadd_utf8(struct parser_params *parser, rb_encoding **encp,
* codepoint without adding it
*/

int codepoint;
size_t numlen;

int codepoint, unicode_p = enctype == 'u', mblen;
size_t numlen, maxlen;
char errmsg[64];
const char *encname = unicode_p ? "Unicode" : (*encp)->name;

if (regexp_literal) { tokadd('\'); tokadd('u'); }

if (regexp_literal) { tokadd('\'); tokadd(enctype); }

if (peek('{')) { /* handle \u{...} form */
maxlen = unicode_p ? 6 : 4;
do {
if (regexp_literal) { tokadd(*lex_p); }
nextc();

 codepoint = scan_hex(lex_p, 6, &numlen);

 codepoint = scan_hex(lex_p, maxlen, &numlen);
 if (numlen == 0)  {

```
 yyerror("invalid Unicode escape");
```

 snprintf(errmsg, sizeof(errmsg), "invalid %s escape", encname);

```
 yyerror(errmsg);
 return 0;
 }
```

```
 if (codepoint > 0x10ffff) {
```

 yyerror("invalid Unicode codepoint (too large)");

 mblen = ONIGENC_CODE_TO_MBCLEN(unicode_p ? UTF8_ENC() : *encp, codepoint);

```
 if (!MBCLEN_CHARFOUND_P(mblen)) {
```

 snprintf(errmsg, sizeof(errmsg), "invalid %s codepoint", encname);

 yyerror(errmsg);
 return 0;
 }
 lex_p += numlen;

@@ -5489,7 +5495,7 @@ parser_tokadd_utf8(struct parser_params *parser, rb_encoding **encp,
tokcopy((int)numlen);
}
else if (codepoint >= 0x80) {

```
 *encp = UTF8_ENC();
```

 if (unicode_p) *encp = UTF8_ENC();
 if (string_literal) tokaddmbc(codepoint, *encp);
 }
 else if (string_literal) {

@@ -5506,16 +5512,18 @@ parser_tokadd_utf8(struct parser_params *parser, rb_encoding *encp,
nextc();
}
else { / handle \uxxxx form */

codepoint = scan_hex(lex_p, 4, &numlen);
if (numlen < 4) {
```
 yyerror("invalid Unicode escape");
```

maxlen = unicode_p ? 4 : 2;
codepoint = scan_hex(lex_p, maxlen, &numlen);
if (numlen < maxlen) {

 snprintf(errmsg, sizeof(errmsg), "invalid %s escape", encname);

```
 yyerror(errmsg);
 return 0;
```
}

lex_p += 4;

lex_p += numlen;
if (regexp_literal) {

```
       tokcopy(4);
```

```
       tokcopy(numlen);
   }
```

else if (codepoint >= 0x80) {

else if (codepoint >= 0x80 && unicode_p) {
*encp = UTF8_ENC();
if (string_literal) tokaddmbc(codepoint, *encp);
}
@@ -5570,6 +5578,9 @@ parser_read_escape(struct parser_params *parser, int flags,
return c;
```
case 'x':	/* hex constant */
```
if (peek('{')) {
}
c = tok_hex(&numlen);
if (numlen == 0) return 0;
return c;
@@ -5825,13 +5836,14 @@ parser_tokadd_string(struct parser_params *parser,
break;
```
  case 'u':
```

   case 'x':
 if ((func & STR_FUNC_EXPAND) == 0) {
     tokadd('\\');
     break;
 }

```
 parser_tokadd_utf8(parser, &enc, 1,
```
```
 		   func & STR_FUNC_SYMBOL,
```

                              func & STR_FUNC_REGEXP);

 parser_tokadd_multibyte(parser, &enc, c, 1,

```
 			func & STR_FUNC_SYMBOL,
```

 			func & STR_FUNC_REGEXP);
 if (has_nonascii && enc != *encp) {
     mixed_escape(beg, enc, *encp);
 }

@@ -6855,9 +6867,9 @@ parser_yylex(struct parser_params *parser)
goto ternary;
}
else if (c == '\') {

```
       if (peek('u')) {
```
```
           nextc();
```

           c = parser_tokadd_utf8(parser, &enc, 0, 0, 0);

```
 c = nextc();
```
```
       if (c == 'u' || c == 'x') {
```

           c = parser_tokadd_multibyte(parser, &enc, c, 0, 0, 0);
           if (0x80 <= c) {
               tokaddmbc(c, enc);
           }

@@ -6866,6 +6878,7 @@ parser_yylex(struct parser_params *parser)
}
}
else {

 pushback(c);
           c = read_escape(0, &enc);
           tokadd(c);
       }

diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 07cda75..28996ab 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -159,6 +159,9 @@ class TestM17N < Test::Unit::TestCase
assert_encoding("EUC-JP", eval(e(%{"\x20"})).encoding)
assert_encoding("EUC-JP", eval(e(%{"\n"})).encoding)
assert_encoding("EUC-JP", eval(e(%{"\x80"})).encoding)