[SLOF] [PATCH v5 1/2] Fix output word

[Thomas Huth]

On 23.03.2018 12:42, Laurent Vivier wrote:
> We can select the console output, but it does not really work
> 
> Implement term-io-emit, as we have term-io-key to really
> send characters to the output selected by stdout.
> 
> Signed-off-by: Laurent Vivier <lvivier at redhat.com>
> ---
>  slof/fs/term-io.fs | 33 ++++++++++++++++++++++++++++-----
>  1 file changed, 28 insertions(+), 5 deletions(-)
> 
> diff --git a/slof/fs/term-io.fs b/slof/fs/term-io.fs
> index 52ce12a..97d02a4 100644
> --- a/slof/fs/term-io.fs
> +++ b/slof/fs/term-io.fs
> @@ -10,6 +10,17 @@
>  \ *     IBM Corporation - initial implementation
>  \ ****************************************************************************/
>  
> +0 VALUE write-xt
> +
> +VARIABLE stdout
> +
> +: set-stdout ( ihandle -- )
> +   \ Close old stdout:
> +   stdout @ ?dup IF close-dev THEN
> +   \ Now set the new stdout:
> +   dup stdout !
> +   encode-int s" stdout" set-chosen
> +;
>  
>  : input  ( dev-str dev-len -- )
>     open-dev ?dup IF
> @@ -24,12 +35,15 @@
>  
>  : output  ( dev-str dev-len -- )
>     open-dev ?dup IF
> -      \ Close old stdout:
> -      s" stdout" get-chosen IF
> -         decode-int nip nip ?dup IF close-dev THEN
> +      \ find new ihandle and xt handle
> +      dup s" write" rot ihandle>phandle find-method
> +      0= IF
> +         drop
> +         cr ." Cannot find the write method for the given output console " cr
> +         EXIT
>        THEN
> -      \ Now set the new stdout:
> -      encode-int s" stdout" set-chosen
> +      to write-xt
> +      set-stdout
>     THEN
>  ;
>  
> @@ -40,6 +54,15 @@
>  
>  1 BUFFER: (term-io-char-buf)
>  
> +: term-io-emit ( char -- )
> +    write-xt 0= IF drop EXIT THEN

Patch looks basically fine to me, but this part is a little bit ugly: As
long as write-xt is 0, there won't be a way to print out any console
output. So between the point in time where term-io.fs is included (i.e.
tree.fs in OF.fs) and the point in time where "output" is called, there
won't be any console output anymore.
To fix this, use the trick that is already used in term-io-key:

  write-xt 0= IF [ ' emit behavior compile, ] THEN

> +    (term-io-char-buf) c!
> +    (term-io-char-buf) 1 write-xt stdout @ call-package
> +    drop
> +;
> +
> +' term-io-emit to emit

 Thomas