Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.forth > #36327

Re: Reducing C,

Show all headers | View raw

on 05/02/2015 14:45:36,  wrote:
> Hi Alex,
> 
> A sentinel makes the code vulnerable.
> It gives the code an extra rule.
> A coder could forget to put the sentinel on the stack or
> the sentinel could inadvertently be removed from the stack.
> 
> Jos
> 

There are lots of things that could create problems; an intervening
definition, an erroneous DROP or two or simply forgetting to write it. A
mnemonic might help.

: starting-here -1 ;
starting-here 10 20 30 40 create test as-cstring

But now it's beginning to look like COBOL.



> On 4 february 2015 22:08:06 UTC+1 Alex McDonald wrote:
>> on 04/02/2015 15:12:05,  wrote:
>> > Agreeing with Alex meant for me the way the allocated space was
>> > filled. Restricting to ANS only is IMO a waste of time.
>> > However I should have included a definition of lcount.
>> >
>> > Refactoring ;bytes sounds attractive.
>> > But it seems the new definitions can only be used in ;bytes
>> > and no where else.
>> > New names like allocate-bytes and fill-allocated-bytes
>> > don't look right for me.
>> >
>> > After reading the mail of Alex and your comment
>> > my code has been changed to:
>> >
>> > [UNDEFINED] lcount [IF]
>> >: lcount ( adr - adr' cnt )   dup @ swap cell+ swap ;
>> > [THEN]
>> >
>> >: ;bytes  ( numbers... -- )
>> > depth last @ name> >body tuck @ - dup 0= abort" Empty stack"
>> > dup >r swap ! here r@ allot
>> > dup r> + 1-
>> > do   i c! -1  +loop
>> > does>  lcount ;
>> >
>> >: long$:  \ compiletime: ( "name" - ) runtime: ( - Adr #items )
>> > create depth ,  ; \ map: n...
>> >
>> > long$: &test2 ( - adr #bytes )  char H char E char Y char !  ;bytes
>> >
>> > cr &test2 type cr .s
>> >
>> >
>> > long$: &test3
>> > 8  0 13  3 10  2  7
>> > 9  5 12  4  1  6 10 ;bytes
>> >
>> > &test3   dump cr .s
>> >
>>
>> I'm not convinced this is the way to go. The syntax seems clunky. How
>> about using a sentinel; -1 seems appropriate here. Factoring is required.
>> The syntax for this is
>>
>> -1 ( the sentinel )
>> <some stack contents>
>> create <name> as-cstring
>>
>> STC Experimental 32bit: 0.06.07 Build: 135
>> here 256 dup allot + constant c-buff  ok
>>  ok
>> : as-cstring ( -1 cn .. c0 -- )
>> \ build counted string cn|..|c0, stop at sentinel -1
>> \ move from stack to temp buffer from high to low
>>     c-buff
>>     begin over 1+ while
>>       1- dup -rot c!
>>     repeat
>> \ allot space for the c string
>>     dup negate c-buff +
>>     here over 1+ allot
>> \ set c-string length
>>     2dup c!
>> \ initialise from buffer
>>     1+ swap move
>>     drop
>>   does> count
>>   ;  ok
>>         ok
>> 20
>> -1 10 20 30 create test as-cstring  ok[1]
>>  ok[1]
>> s [1] 20  ok[1]
>> test dump
>>   80522D | 0A 14 1E                                         |...| ok[1]
> 
> 

Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Reducing C, josv@planet.nl - 2015-01-28 04:07 -0800
  Re: Reducing C, Mark Wills <markwills1970@gmail.com> - 2015-01-28 05:02 -0800
  Re: Reducing C, Howerd <howerdo@yahoo.co.uk> - 2015-01-28 07:42 -0800
    Re: Reducing C, josv@planet.nl - 2015-01-28 08:17 -0800
  Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-01-29 03:37 +1100
  Re: Reducing C, visualforth@rocketmail.com - 2015-01-28 12:53 -0800
  Re: Reducing C, humptydumpty <ouatubi@gmail.com> - 2015-01-28 14:03 -0800
  Re: Reducing C, humptydumpty <ouatubi@gmail.com> - 2015-01-28 20:39 -0800
    Re: Reducing C, humptydumpty <ouatubi@gmail.com> - 2015-01-28 20:51 -0800
      Re: Reducing C, josv@planet.nl - 2015-01-29 06:28 -0800
  Re: Reducing C, hughaguilar96@gmail.com - 2015-01-29 21:18 -0800
    Re: Reducing C, josv@planet.nl - 2015-01-30 05:38 -0800
      Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-01-30 15:11 +0000
        Re: Reducing C, josv@planet.nl - 2015-01-30 08:34 -0800
      Re: Reducing C, hughaguilar96@gmail.com - 2015-01-31 20:26 -0800
        Re: Reducing C, josv@planet.nl - 2015-02-01 11:16 -0800
          Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-02-02 11:03 +1100
            Re: Reducing C, "Elizabeth D. Rather" <erather@forth.com> - 2015-02-01 14:13 -1000
              Re: Reducing C, hughaguilar96@gmail.com - 2015-02-01 17:22 -0800
              Re: Reducing C, hughaguilar96@gmail.com - 2015-02-01 17:36 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-02 11:40 +0000
                Re: Reducing C, Mark Wills <markwills1970@gmail.com> - 2015-02-02 05:24 -0800
                Netiquette was: Re: Reducing C, albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-02 13:40 +0000
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-02 15:08 +0000
                Politeness, was Re: Reducing C, "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-02 19:30 -0500
                Re: Politeness, was Re: Reducing C, awegel@arcor.de (Alexander Wegel) - 2015-02-03 01:57 +0100
                Re: Politeness, was Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-03 11:59 +0000
                Re: Reducing C, josv@planet.nl - 2015-02-03 02:31 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-03 12:06 +0000
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-03 19:47 +0000
                Re: Reducing C, josv@planet.nl - 2015-02-03 14:06 -0800
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-03 21:19 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-04 12:10 +0000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-04 18:22 -0800
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-04 19:04 -0800
                Re: Reducing C, stephen@mpeforth.com (Stephen Pelc) - 2015-02-05 11:33 +0000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-05 19:39 -0800
                Re: Reducing C, stephen@mpeforth.com (Stephen Pelc) - 2015-02-06 11:50 +0000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-06 11:28 -0800
                Re: Reducing C, Mark Wills <markwills1970@gmail.com> - 2015-02-05 04:37 -0800
                Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-02-06 21:47 +1100
                Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-02-13 09:45 +1100
                Re: Reducing C, Mark Wills <markwills1970@gmail.com> - 2015-02-13 05:24 -0800
                Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-02-15 13:53 +1100
                Re: Reducing C, Mark Wills <markwills1970@gmail.com> - 2015-02-16 01:07 -0800
                Re: Reducing C, anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-16 15:02 +0000
                Re: Reducing C, "HAA" <someone@microsoft.com> - 2015-02-19 14:22 +1100
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-05 13:18 +0000
                Re: Reducing C, josv@planet.nl - 2015-02-05 07:02 -0800
                Re: Reducing C, josv@planet.nl - 2015-02-05 07:14 -0800
                Re: Reducing C, josv@planet.nl - 2015-02-07 07:12 -0800
                Re: Reducing C, josv@planet.nl - 2015-02-04 07:12 -0800
                Re: Reducing C, november.nihal@gmail.com - 2015-02-04 09:38 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-04 21:08 +0000
                Re: Reducing C, josv@planet.nl - 2015-02-05 06:45 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-06 13:21 +0000
                Re: Reducing C, awegel@arcor.de (Alexander Wegel) - 2015-02-05 17:36 +0100
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-05 17:06 +0000
                Re: Reducing C, awegel@arcor.de (Alexander Wegel) - 2015-02-05 18:17 +0100
                Re: Reducing C, "Elizabeth D. Rather" <erather@forth.com> - 2015-02-05 10:40 -1000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-05 20:25 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-06 11:39 +0000
                Re: Reducing C, awegel@arcor.de (Alexander Wegel) - 2015-02-06 12:48 +0100
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-06 17:28 -0800
                Re: Reducing C, awegel@arcor.de (Alexander Wegel) - 2015-02-07 12:38 +0100
                Re: Reducing C, albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-06 14:40 +0000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-06 18:33 -0800
                Re: Reducing C, anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-06 13:49 +0000
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-06 14:15 +0000
                Re: Reducing C, hughaguilar96@gmail.com - 2015-02-03 21:23 -0800
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-04 12:41 +0000
                Re: Reducing C, "WJ" <w_a_x_man@yahoo.com> - 2015-02-04 18:19 +0000
                Re: Reducing C, "WJ" <w_a_x_man@yahoo.com> - 2015-02-04 20:54 +0000
                Re: Reducing C, "WJ" <w_a_x_man@yahoo.com> - 2015-02-04 09:41 +0000
                Re: Reducing C, "Alex McDonald" <blog@rivadpm.com> - 2015-02-04 12:54 +0000

csiph-web