# Invalid error message by illegal regexp

**URL:** <https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052>\
**Category:** Development\
**Created:** [August 2, 2007, 6:46am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052 "2007-08-02T06:46:01Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 2, 2007, 6:46am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/1 "2007-08-02T06:46:01Z")

</div>

e$BLZB\<$G$9!#e(B

1.9e$B$NJ}$N$\_$G$9$,!"e(B

ruby -e “/a(?=b)?/.match(‘a’)”  
e$B$H$+e(B  
ruby -e “/a(?=b?/.match(‘a’)”  
e$B$H$7$?$H$-$K!"e(B

0: uninitialized Regexp (TypeError)

e$B$H$$$&E,@Z$G$O$J$$$G$"$m$&%(%i!\<%a%C%;!\<%8$,=PNO$5$l$^$9!#e(B  
ruby 1.9.0 (2007-07-30 patchlevel 0) [i386-mswin32\_71] e$B$G3NG’!#e(B

e$B$3$l$O54\<V$,JV$7$F$$$k%(%i!\<%a%C%;!\<%8$r0.$j$D$V$7$F$7$^$C$F$$$k$?$ae(B  
e$B$G$9!#0J2\<\>:Y!#e(B

VALUE  
rb\_reg\_compile(const char \*s, long len, int options, const char \*file,  
int line)  
{  
VALUE re = rb\_reg\_s\_alloc(rb\_cRegexp);  
char err[ONIG\_MAX\_ERROR\_MESSAGE\_LEN];

```
if (rb_reg_initialize(re, s, len, options, err) != 0) {
    VALUE desc = rb_reg_desc(s, len, re);

```

rb\_compile\_error(file, line, “%s: %s”, err, RSTRING\_PTR(desc));  
}  
FL\_SET(re, REG\_LITERAL);  
return re;  
}

e$B$3$3$N!“e(Brb\_reg\_initilize  
e$B7PM3$G@55,I=8=$r%3%s%Q%$%k$7$?$H$-$Ke(B  
e$B54\<VB&$N%(%i!\<$K$J$jLa$jCM$,e(B  
-1e$B!”%(%i!\<$N860x$rI=$954\<VB&$+$i$N%a%C%;!\<e(B  
e$B%8$,e(B erre$B$K@\_Dj$5$l$k$N$G$9$,!"e(B

e$B\<!$K8F$S=P$7$F$$$ke(B rb\_reg\_desc e$B$NCf$Ge(B

```
if (re) {

```

rb\_reg\_check(re);

e$B$He(B rb\_reg\_check e$B$r8F$S=P$7!"$=$Ne(B rb\_reg\_check e$B$Ge(B

rb\_reg\_check(VALUE re)  
{  
if (!RREGEXP(re)-\>ptr || !RREGEXP(re)-\>str) {  
rb\_raise(rb\_eTypeError, “uninitialized Regexp”);  
}  
}

e$B$He(B rb\_raise e$B$7$F$7$^$C$F$$$k$N$G!"e(B  
0: uninitialized Regexp (TypeError)  
e$B$H$$$&%a%C%;!\<%8$@$1=PNO$5$l$F=\*$o$j$K$J$C$F$7$^$$$^$9e(B  
(rb\_compile\_errore$B$,8F$S=P$5$l$J$$e(B)e$B!#e(B

rb\_reg\_initialize e$B$G\<:GT$7$?e(B(not  
0e$B$,JV$C$F$-$?e(B)e$B$H$-$NBP=h$rJQ$($k$+e(B  
rb\_reg\_desce$BFbIt$NH=Dj$rD4@a$9$l$PNI$$$H;W$$$^$9$,!"6qBNE\*$J=$@5J}K!e(B  
e$B$O$\*G$$;$7$^$9!#e(B

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 2, 2007, 8:40am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/2 "2007-08-02T08:40:10Z")

</div>

e$B$J$+$@$G$9!#e(B

At Thu, 2 Aug 2007 13:45:04 +0900,  
KIMURA Koichi wrote in [ruby-dev:31333]:

> ruby -e “/a(?=b)?/.match(‘a’)”  
> e$B$H$+e(B  
> ruby -e “/a(?=b?/.match(‘a’)”  
> e$B$H$7$?$H$-$K!"e(B
> 
> 0: uninitialized Regexp (TypeError)
> 
> e$B$H$$$&E,@Z$G$O$J$$$G$"$m$&%(%i!\<%a%C%;!\<%8$,=PNO$5$l$^$9!#e(B

e$B$9$$$^$;$s!#D\>$=$&$H$O;W$C$F$$$?$s$G$9$,!"8e2s$7$K$7$?$^$^K:$l$Fe(B  
e$B$^$7$?!#e(B

> rb\_reg\_initialize e$B$G\<:GT$7$?e(B(not 0e$B$,JV$C$F$-$?e(B)e$B$H$-$NBP=h$rJQ$($k$+e(B  
> rb\_reg\_desce$BFbIt$NH=Dj$rD4@a$9$l$PNI$$$H;W$$$^$9$,!"6qBNE\*$J=$@5J}K!e(B  
> e$B$O$\*G$$;$7$^$9!#e(B

e$B85!9$O!“e(Brb\_compile\_errore$B$r8F$V$H$-$Oe(Brb\_reg\_desce$B$K$Oe(B0e$B$rEO$7$F$$$?e(B  
e$B$N$G!”\<:GT$7$?$ie(B rb\_reg\_desc(s, len, 0)  
e$B$G$b$$$$$H;W$$$^$9$,!"%\*e(B  
e$B%W%7%g%s$,I=\<($5$l$F$$$J$$$3$H$K5$$,$D$-$^$7$?!#e(B

e$B%\*%W%7%g%s$NJQ492s$j$b@0M}$7$F!"$3$s$J$H$3$m$G$I$&$G$7$g$&$+!#e(B

# Index: re.c

— re.c (revision 12861)  
+++ re.c (working copy)  
@@ -197,4 +197,39 @@ char\_to\_option(int c)  
}

+static char \*  
+option\_to\_str(char str[4], int options)  
+{

- char \*p = str;
- if (options & ONIG\_OPTION\_MULTILINE) \*p++ = ‘m’;
- if (options & ONIG\_OPTION\_IGNORECASE) \*p++ = ‘i’;
- if (options & ONIG\_OPTION\_EXTEND) \*p++ = ‘x’;
- \*p = 0;
- return str;  
+}
- 

+static const char \*  
+arg\_kcode(int options)  
+{

- switch (options & ARG\_KCODE\_MASK) {
- 

```
 case ARG_KCODE_NONE: return "n";

```

- 

```
 case ARG_KCODE_EUC: return "e";

```

- 

```
 case ARG_KCODE_SJIS: return "s";

```

- 

```
 case ARG_KCODE_UTF8: return "u";

```

- }
- return “”;  
+}
- 

+static const char \*  
+opt\_kcode(int flags)  
+{

- switch (flags) {
- 

```
 case KCODE_NONE: return "n";

```

- 

```
 case KCODE_EUC: return "e";

```

- 

```
 case KCODE_SJIS: return "s";

```

- 

```
 case KCODE_UTF8: return "u";

```

- }
- return “”;  
+}
- 

extern int  
rb\_char\_to\_option\_kcode(int c, int \*option, int \*kcode)  
@@ -417,27 +452,11 @@ rb\_reg\_desc(const char \*s, long len, VAL  
rb\_str\_buf\_cat2(str, “/”);  
if (re) {

- char opts[4];  
rb\_reg\_check(re);

- if (RREGEXP(re)-\>ptr-\>options & ONIG\_OPTION\_MULTILINE)
- 

```
 rb_str_buf_cat2(str, "m");

```

- if (RREGEXP(re)-\>ptr-\>options & ONIG\_OPTION\_IGNORECASE)
- 

```
 rb_str_buf_cat2(str, "i");

```

- if (RREGEXP(re)-\>ptr-\>options & ONIG\_OPTION\_EXTEND)
- 

```
 rb_str_buf_cat2(str, "x");

```

- if (\*option\_to\_str(opts, RREGEXP(re)-\>ptr-\>options))

- 

```
 rb_str_buf_cat2(str, opts);

```

if (FL\_TEST(re, KCODE\_FIXED)) {

- 

```
 switch ((RBASIC(re)->flags & KCODE_MASK)) {

```

- 

```
   case KCODE_NONE:

```

- rb\_str\_buf\_cat2(str, “n”);
- break;
- 

```
   case KCODE_EUC:

```

- rb\_str\_buf\_cat2(str, “e”);
- break;
- 

```
   case KCODE_SJIS:

```

- rb\_str\_buf\_cat2(str, “s”);
- break;
- 

```
   case KCODE_UTF8:

```

- rb\_str\_buf\_cat2(str, “u”);
- break;
- 

```
 }

```

- 

```
 rb_str_buf_cat2(str, opt_kcode(RBASIC(re)->flags & KCODE_MASK));

```

}  
}  
@@ -514,4 +533,5 @@ rb\_reg\_to\_s(VALUE re)  
const UChar\* ptr;  
VALUE str = rb\_str\_buf\_new2("(?");

- char optbuf[5];

- if (options & ONIG\_OPTION\_MULTILINE) rb\_str\_buf\_cat2(str, “m”);
- if (options & ONIG\_OPTION\_IGNORECASE) rb\_str\_buf\_cat2(str, “i”);
- if (options & ONIG\_OPTION\_EXTEND) rb\_str\_buf\_cat2(str, “x”);

- if (\*option\_to\_str(optbuf, options)) rb\_str\_buf\_cat2(str, optbuf);

- rb\_str\_buf\_cat2(str, “-”);
- if (!(options & ONIG\_OPTION\_MULTILINE)) rb\_str\_buf\_cat2(str, “m”);
- if (!(options & ONIG\_OPTION\_IGNORECASE)) rb\_str\_buf\_cat2(str, “i”);
- if (!(options & ONIG\_OPTION\_EXTEND)) rb\_str\_buf\_cat2(str, “x”);

- optbuf[0] = ‘-’;
- option\_to\_str(optbuf + 1, ~options)
- rb\_str\_buf\_cat2(str, optbuf);  
}

@@ -1528,5 +1545,12 @@ rb\_reg\_compile(const char \*s, long len,

```
 if (rb_reg_initialize(re, s, len, options, err) != 0) {

```

- VALUE desc = rb\_reg\_desc(s, len, re);

- char opts[6];
- VALUE desc = rb\_str\_buf\_new2("/");
- 
- rb\_reg\_expr\_str(desc, s, len);
- opts[0] = ‘/’;
- option\_to\_str(opts + 1, options);
- strlcat(opts, arg\_kcode(options), sizeof(opts));
- rb\_str\_buf\_cat2(desc, opts);  
rb\_compile\_error(file, line, “%s: %s”, err, RSTRING\_PTR(desc));  
}  
@@ -2066,20 +2090,9 @@ rb\_reg\_s\_union(int argc, VALUE \*argv)  
args[0] = source;  
args[1] = Qnil;

- 

```
   switch (kcode) {

```

- 

```
     case -1:

```

- 

```
   if (kcode == -1) {
       args[2] = Qnil;

```

- 

```
       break;

```

- 

```
     case KCODE_NONE:

```

- 

```
       args[2] = rb_str_new2("n");

```

- 

```
       break;

```

- 

```
     case KCODE_EUC:

```

- 

```
       args[2] = rb_str_new2("e");

```

- 

```
       break;

```

- 

```
     case KCODE_SJIS:

```

- 

```
       args[2] = rb_str_new2("s");

```

- 

```
       break;

```

- 

```
     case KCODE_UTF8:

```

- 

```
       args[2] = rb_str_new2("u");

```

- 

```
       break;

```

- }
- else {
- 

```
       args[2] = rb_str_new2(opt_kcode(kcode));
   }
   return rb_class_new_instance(3, args, rb_cRegexp);
```

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 2, 2007, 9:50am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/3 "2007-08-02T09:50:17Z")

</div>

e$BLZB\<$G$9!#e(B

On Thu, 2 Aug 2007 15:38:36 +0900  
Nobuyoshi N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> > 0: uninitialized Regexp (TypeError)
> > 
> > e$B$H$$$&E,@Z$G$O$J$$$G$"$m$&%(%i!\<%a%C%;!\<%8$,=PNO$5$l$^$9!#e(B
> 
> e$B$9$$$^$;$s!#D\>$=$&$H$O;W$C$F$$$?$s$G$9$,!"8e2s$7$K$7$?$^$^K:$l$Fe(B  
> e$B$^$7$?!#e(B

e$B$“!”:EB%$7$F$7$^$C$?$h$&$J7A$K$J$C$F?=$7Lu$J$$$G$9!#e(B

e$B%Q%C%A$G$9$,!“0l2U=j9TKv$N%;%\_%3%m%s$,H4$1$F$$$k$H$3$m$,$”$j$^$7$?!#e(B

> - optbuf[0] = ‘-’;
> - option\_to\_str(optbuf + 1, ~options)
> - rb\_str\_buf\_cat2(str, optbuf);

e$B??$sCf$N9Te(B(e$B$:$l$F$J$1$l$Pe(B re.c  
e$B$Ne(B605e$B9TL\e(B)e$B$,$=$l$G$9!#e(B

> ruby -e “/a(?=b)?/.match(‘a’)”  
> error oniguruma: target of repeat operator is invalid  
> -e:1: target of repeat operator is invalid: /a(?=b)?/  
> -e:1:in `match': uninitialized Regexp (TypeError) from -e:1:in `’

> ruby -e “/a(?:b/.match(‘a’)”  
> error oniguruma: end pattern with unmatched parenthesis  
> -e:1: end pattern with unmatched parenthesis: /a(?:b/  
> -e:1:in `match': uninitialized Regexp (TypeError) from -e:1:in `’

e$B$N$h$&$K!"54\<V$+$i$N%a%C%;!\<%8$b=PNO$5$l$k$3$H$r3NG’$7$^$7$?!#e(B

e$B$H$3$m$Ge(B a(?=b)?  
e$B$H$$$&@55,I=8=$J$s$G$9$,!"e(B2e$B$A$c$s$M$k$Ne(BRubye$B%9%l$Ge(B  
e$BOCBj$K$G$?$b$N$G$9!#e(B  
#e$B$4B8CN$NJ}$bB?$$$G$7$g$&$1$Ie(B

Ruby 1.8.6 e$B$G$O%(%i!\<$K$O$J$j$^$;$s$,!"%^%C%AF0:n$,4|BTDL$je(B(‘a’  
e$B$H$+e(B  
‘ab’ e$B$K%^%C%Ae(B)e$B$N$b$N$G$O$J$$$h$&$G$9!#e(BRuby 1.9  
e$B$G$O\>e5-$NDL$j%(%i!\<$Ke(B  
e$B$J$j$^$9!#e(B

e$B$G!“\<ALd$J$s$G$9$,!”$3$&$$$&7Ae(B(e$B@hFI$_e(B =  
e$BI}$,$J$$$b$N$N7+$jJV$7e(B)e$B$H$$$&$N$Oe(B  
e$B$I$&$9$Y$-$J$s$G$7$g$&$+e(B?  
e$B54\<V$NF0:n$K4X$7$F$O\>.Gw$5$s$,0U?^E\*$K$3$&$7$Fe(B  
e$B$$$k$h$&$J5$$,$7$J$$$G$b$"$j$^$;$se(B(e$BK\Ev$K$=$&$J$N$+$O3N$+$a$F$_$J$$$H$oe(B  
e$B$+$j$^$;$s$,e(B)e$B!#e(B

e$B$o$?$7$N0U8+$O8=\>u$N54\<V$N\<BAu$NDL$j%(%i!\<$K$7$A$c$C$F$$$$$s$8$c$J$$$+e(B  
e$B$H$$$&$b$N$G$9!#e(B

e$B$?$@$7B\>$N=hM}7O$rD4$Y$F$\_$k$He(B

Perl 5.8.8  
Python 2.5.1  
Java (1.5.10e$B$/$i$$e(B?)  
.NET (2.0)

e$B$O%(%i!\<$K$J$i$:!"e(B

PHP (5.2.1, preg\_\*)  
e$B$O%(%i!\<$K$J$j$^$7$?!#e(B

# Warning: preg\_match(): Compilation failed: nothing to repeat at offset

#6 in Command line code on line 1)

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 2, 2007, 10:14am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/4 "2007-08-02T10:14:19Z")

</div>

e$B$J$+$@$G$9!#e(B

At Thu, 2 Aug 2007 16:49:35 +0900,  
KIMURA Koichi wrote in [ruby-dev:31336]:

> e$B%Q%C%A$G$9$,!“0l2U=j9TKv$N%;%\_%3%m%s$,H4$1$F$$$k$H$3$m$,$”$j$^$7$?!#e(B

e$B$D$$$&$C$+$j!#e(B

> ```
> from -e:1:in `<main>'
> 
> ```
> 
> e$B$N$h$&$K!"54\<V$+$i$N%a%C%;!\<%8$b=PNO$5$l$k$3$H$r3NG’$7$^$7$?!#e(B

e$B%3%s%Q%$%k%(%i!\<$J$N$Ke(Bmatche$B$,\<B9T$5$l$k$N$b4V0c$C$F$$$k$N$G$9$,!"e(B  
e$B$3$l$K$D$$$F$O$5$5$@$5$s$H8!F$Cf$G$9!#e(B

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 2, 2007, 9:17am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/5 "2007-08-02T09:17:14Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:31334] Re: Invalid error message by illegal  
regexp”  
on Thu, 2 Aug 2007 15:38:36 +0900, Nobuyoshi N.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B85!9$O!“e(Brb\_compile\_errore$B$r8F$V$H$-$Oe(Brb\_reg\_desce$B$K$Oe(B0e$B$rEO$7$F$$$?e(B  
|e$B$N$G!”\<:GT$7$?$ie(B rb\_reg\_desc(s, len, 0) e$B$G$b$$$$$H;W$$$^$9$,!“%_e(B  
|e$B%W%7%g%s$,I=\<($5$l$F$$$J$$$3$H$K5$$,$D$-$^$7$?!#e(B  
|  
|e$B%_%W%7%g%s$NJQ492s$j$b@0M}$7$F!”$3$s$J$H$3$m$G$I$&$G$7$g$&$+!#e(B

e$B\<B$O%Q%C%A$rFI$s$G$J$$$N$G$9$,!"?.$8$^$9!#%3%\_%C%H$7$F$/$@$5e(B  
e$B$$$^$;!#e(B

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 13, 2007, 1:37am UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/6 "2007-08-13T01:37:48Z")

</div>

e$B$J$+$@$G$9!#e(B

At Mon, 13 Aug 2007 03:02:26 +0900,  
SASADA Koichi wrote in [ruby-dev:31382]:

> > e$B%3%s%Q%$%k%(%i!\<$J$N$Ke(Bmatche$B$,\<B9T$5$l$k$N$b4V0c$C$F$$$k$N$G$9$,!"e(B  
> > e$B$3$l$K$D$$$F$O$5$5$@$5$s$H8!F$Cf$G$9!#e(B
> 
> e$B!!J|CV$7$F$$$F$9$\_$^$;$s!#$3$N7o$I$&$J$C$F$k$s$G$7$?$C$1!#e(B

e$B@.8y$J$ie(BRegexpe$B!“%(%i!\<$,$”$C$?$ie(BStringe$B$rJV$9!“$H$$$&$N$,5$$KF~$ie(B  
e$B$J$$$H$$$&$N$O$”$j$^$9$,!“0l1~=$@5$7$F$”$j$^$9!#e(B

Thu Aug 2 23:42:57 2007 Nobuyoshi N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

- parse.y (reg\_compile\_gen): set error if failed to compile regexp  
literal. [ruby-dev:31336]

---

<div class="post-metadata">

**Author:** ![KIMURA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/ce7236/32.png) [@KIMURA\_Koichi](https://www.ruby-forum.com/u/KIMURA_Koichi)\
**Post date:** [August 12, 2007, 8:03pm UTC](https://www.ruby-forum.com/t/invalid-error-message-by-illegal-regexp/111052/7 "2007-08-12T20:03:19Z")

</div>

e$B!!$5$5$@$G$9!#e(B

Nobuyoshi N. wrote:

> e$B%3%s%Q%$%k%(%i!\<$J$N$Ke(Bmatche$B$,\<B9T$5$l$k$N$b4V0c$C$F$$$k$N$G$9$,!"e(B  
> e$B$3$l$K$D$$$F$O$5$5$@$5$s$H8!F$Cf$G$9!#e(B

e$B!!J|CV$7$F$$$F$9$\_$^$;$s!#$3$N7o$I$&$J$C$F$k$s$G$7$?$C$1!#e(B