CDL values

CDL values

[Gary Thomas]

I'd like to have a CDL variable, flavor data, whose value
is specified as a single character.  I've not found any way
to write this, other than using the ASCII HEX equivalent.

If I write this:
  cdl_option XYZ {
    flavor data
    default_value 'a'
  }
I always get a syntax error.

Ideas?  Is this possible?

n.b. this is used in some C code where I'd like to say
  a = ch - XYZ;
instead of
  a = ch = 'a';

Thanks

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

Re: CDL values

[GONZALEZ Laurent]

On Tue, 05 Apr 2005 09:11:52 -0600
Gary Thomas <gary@mlbassoc.com> wrote:

> I'd like to have a CDL variable, flavor data, whose value
> is specified as a single character.  I've not found any way
> to write this, other than using the ASCII HEX equivalent.
> 
> If I write this:
>   cdl_option XYZ {
>     flavor data
>     default_value 'a'
>   }
> I always get a syntax error.
> 
> Ideas?  Is this possible?
> 
> n.b. this is used in some C code where I'd like to say
>   a = ch - XYZ;
> instead of
>   a = ch = 'a';
> 

This is a bit ugly, but the following should do the job:

  cdl_option XYZ {
    flavor data
    default_value \"a\"
	define_format "'%s'"
  }

regards.

-- 
GONZALEZ Laurent
------------------------------------
Real-Time OS Team Leader
TRANGO Systems - Groupe ELSYS Design
74, avenue des Martyrs
38000 Grenoble
Tel: 33 (0)4 76 12 28 44
Fax: 33 (0)4 76 12 28 49
http://www.trango-systems.com

Re: CDL values

[Bart Veer]

>>>>> "Gary" == Gary Thomas <gary@mlbassoc.com> writes:

    Gary> I'd like to have a CDL variable, flavor data, whose value
    Gary> is specified as a single character.  I've not found any way
    Gary> to write this, other than using the ASCII HEX equivalent.

    Gary> If I write this:
    Gary>   cdl_option XYZ {
    Gary>     flavor data
    Gary>     default_value 'a'
    Gary>   }
    Gary> I always get a syntax error.

    Gary> Ideas?  Is this possible?

Sure, but not that way. In CDL as in Tcl everything is really a
string, there is no concept of individual chars. Instead you should be
able to do something like (untested):

  cdl_option XYZ {
      flavor		data
      default_value	{ "'a'" }
      legal_values {
          "'a'" "'b'" "'c'" "'d'" "'e'" "'f'" "'g'" "'h'" "'i'" 
          "'j'" "'k'" "'l'" "'m'" "'n'" "'o'" "'p'" "'q'" "'r'" 
          "'s'" "'t'" "'u'" "'v'" "'w'" "'x'" "'y'" "'z'"
      }
  }

The outer braces stop the Tcl interpreter from handling the quotes, so
CDL sees default_value "'a'" and will treat this as the string 'a'.
The legal_values list enforces the single character limit.

Alternatively you can leave out the ' marks from the values and put
them in with a define_format:

  cdl_option XYZ {
      flavor		data
      default_value	{ "a" }
      legal_values {
          "a" "b" "c" "d" "e" "f" "g" "h" "i" 
          "j" "k" "l" "m" "n" "o" "p" "q" "r" 
          "s" "t" "u" "v" "w" "x" "y" "z"
      }
      define_format "'%s'"
  }

Bart

-- 
Bart Veer                       eCos Configuration Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts

Re: CDL values

[Gary Thomas]

On Tue, 2005-04-05 at 16:48 +0100, Bart Veer wrote:
> >>>>> "Gary" == Gary Thomas <gary@mlbassoc.com> writes:
> 
>     Gary> I'd like to have a CDL variable, flavor data, whose value
>     Gary> is specified as a single character.  I've not found any way
>     Gary> to write this, other than using the ASCII HEX equivalent.
> 
>     Gary> If I write this:
>     Gary>   cdl_option XYZ {
>     Gary>     flavor data
>     Gary>     default_value 'a'
>     Gary>   }
>     Gary> I always get a syntax error.
> 
>     Gary> Ideas?  Is this possible?
> 
> Sure, but not that way. In CDL as in Tcl everything is really a
> string, there is no concept of individual chars. Instead you should be
> able to do something like (untested):
> 
>   cdl_option XYZ {
>       flavor		data
>       default_value	{ "'a'" }
>       legal_values {
>           "'a'" "'b'" "'c'" "'d'" "'e'" "'f'" "'g'" "'h'" "'i'" 
>           "'j'" "'k'" "'l'" "'m'" "'n'" "'o'" "'p'" "'q'" "'r'" 
>           "'s'" "'t'" "'u'" "'v'" "'w'" "'x'" "'y'" "'z'"
>       }
>   }
> 
> The outer braces stop the Tcl interpreter from handling the quotes, so
> CDL sees default_value "'a'" and will treat this as the string 'a'.
> The legal_values list enforces the single character limit.
> 
> Alternatively you can leave out the ' marks from the values and put
> them in with a define_format:
> 
>   cdl_option XYZ {
>       flavor		data
>       default_value	{ "a" }
>       legal_values {
>           "a" "b" "c" "d" "e" "f" "g" "h" "i" 
>           "j" "k" "l" "m" "n" "o" "p" "q" "r" 
>           "s" "t" "u" "v" "w" "x" "y" "z"
>       }
>       define_format "'%s'"
>   }

I chose the latter and it works fine, thanks.

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------