Re: Bug Report: \y, \B, \<, \> do not work with _

[Aharon Robbins]

Greetings.  Concerning this:

> Date: Fri, 01 Dec 2000 12:09:03 +0100
> From: Servatius Brandt <address@hidden>
> To: address@hidden
> CC: address@hidden
> Subject: Bug Report: \y, \B, \<, \> do not work with _
>
> Hello,
>
> The \y, \B, \<, \> patterns do not regard _ as
> word-constituent (unlike \w and \W, which do).
>
> Operating system: ReliantUNIX-Y 5.44 C2001 RM600 R10000
> Version of gawk: 3.0.6
> C-Compiler: Fujitsu Siemens Computers CDS++ V2.0C0004
>
> Test program:
>
> #!/usr/local/bin/gawk -f
>
> BEGIN {
>      print match("X _abc Y", /\<_abc/)                # bug
>      print match("X _abc Y", /\y_abc/)                # bug
>      print match("X abc_ Y", /abc_\>/)                # bug
>      print match("X abc_ Y", /abc_\y/)                # bug
>      print match("X abc_def Y", /abc_\Bdef/)  # bug
>
>      print match("X a_c Y", /a\wc/)           # ok!
>      print match("X a.c Y", /a\Wc/)           # ok!
>      exit
> }
>
>
> Regards,
> Servatius Brandt

This is indeed a bug.  Here is an unofficial patch that fixes the
problem.  My development version uses newer versions of dfa.[ch]
and regex.[ch] and your test program worked there; this patch is
against 3.0.6.

Let me say "thank you" for an excellent bug report.  This made it
quite easy to see the problem and track it down.

Arnold Robbins
--------------------------------------------------------------
*** ../gawk-3.0.6/dfa.c Fri May  2 04:36:18 1997
--- dfa.c       Sun Dec  3 15:28:25 2000
***************
*** 1547,1552 ****
--- 1547,1553 ----
        for (i = 0; i < NOTCHAR; ++i)
        if (ISALNUM(i))
          setbit(i, letters);
+       setbit('_', letters);
        setbit('\n', newline);
      }
  
***************
*** 1680,1686 ****
        for (i = 0; i < NOTCHAR; ++i)
        if (i == '\n')
          trans[i] = state_newline;
!       else if (ISALNUM(i))
          trans[i] = state_letter;
        else
          trans[i] = state;
--- 1681,1687 ----
        for (i = 0; i < NOTCHAR; ++i)
        if (i == '\n')
          trans[i] = state_newline;
!       else if (ISALNUM(i) || i == '_')
          trans[i] = state_letter;
        else
          trans[i] = state;
***************
*** 1741,1747 ****
  
              if (c == '\n')
                trans[c] = state_newline;
!             else if (ISALNUM(c))
                trans[c] = state_letter;
              else if (c < NOTCHAR)
                trans[c] = state;
--- 1742,1748 ----
  
              if (c == '\n')
                trans[c] = state_newline;
!             else if (ISALNUM(c) || c == '_')
                trans[c] = state_letter;
              else if (c < NOTCHAR)
                trans[c] = state;
***************
*** 1890,1896 ****
        for (i = 0; i < NOTCHAR; ++i)
        if (i == '\n')
          sbit[i] = 4;
!       else if (ISALNUM(i))
          sbit[i] = 2;
        else
          sbit[i] = 1;
--- 1891,1897 ----
        for (i = 0; i < NOTCHAR; ++i)
        if (i == '\n')
          sbit[i] = 4;
!       else if (ISALNUM(i) || i == '_')
          sbit[i] = 2;
        else
          sbit[i] = 1;
--
Aharon (Arnold) Robbins --- Pioneer Consulting Ltd.     address@hidden
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