regexp bug?

regexp bug?

[Eliot Handelman]

This doesn't seem right:


        Objective Caml version 3.08.0
open Str

let search r str =
  search_forward (regexp r) str 0;
  matched_string str;;
 
# search "[aA-zZ]+" "_test";;
- : string = "_test"

whereas:

# search "[a-zA-Z]+" "_test";;
- : string = "test"


-- eliot

Re: [Caml-list] regexp bug?

[Hal Daume III]

Why not?  ord('_') is 95, which is between ord('A') = 65 and ord('z'), 
which is 122.  OTOH, it is not between ord('A') = 65 and ord('Z') = 90 OR 
ord('a') = 97 and ord('z') = 122.

the first regexp matches anything in the set
  {a} union {Z} union {everything between A and z}

while the second matches anything in the set
  {everything between a and z} union {everything between A and Z}

On Tue, 3 May 2005, Eliot Handelman wrote:

> This doesn't seem right:
> 
> 
>         Objective Caml version 3.08.0
> open Str
> 
> let search r str =
>   search_forward (regexp r) str 0;
>   matched_string str;;
>  
> # search "[aA-zZ]+" "_test";;
> - : string = "_test"
> 
> whereas:
> 
> # search "[a-zA-Z]+" "_test";;
> - : string = "test"
> 
> 
> -- eliot
> 
> _______________________________________________
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> 

-- 
 Hal Daume III                                   | hdaume@isi.edu
 "Arrest this man, he talks in maths."           | www.isi.edu/~hdaume

Re: [Caml-list] regexp bug?

[Eliot Handelman]

Hal Daume III wrote:

>the first regexp matches anything in the set
>  {a} union {Z} union {everything between A and z}
>
>  
>

Ok, I stand corrected.  I haven't used regexp for years and seemed to 
remember [aA-zZ] as an idiom for any letter.

-- eliot

Re: [Caml-list] regexp bug?

[Jason Hickey]

You may wish to visit, for example, the egrep(1) man page for a 
description of regular expressions.  Note that the [a-zA-Z] and [aA-zZ] 
regular expressions are different.  The former contains the alphabetic 
characters.  The latter is equivalent to [A-z], which in ASCII also 
contains several other characters between 'A' and 'z', including '_'.

Jason

Eliot Handelman wrote:
> This doesn't seem right:
> 
> 
>        Objective Caml version 3.08.0
> open Str
> 
> let search r str =
>  search_forward (regexp r) str 0;
>  matched_string str;;
> 
> # search "[aA-zZ]+" "_test";;
> - : string = "_test"
> 
> whereas:
> 
> # search "[a-zA-Z]+" "_test";;
> - : string = "test"
> 
> 
> -- eliot
> 
> _______________________________________________
> Caml-list mailing list. Subscription management:
> http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list
> Archives: http://caml.inria.fr
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

-- 
Jason Hickey                  http://www.cs.caltech.edu/~jyh
Caltech Computer Science      Tel: 626-395-6568 FAX: 626-792-4257