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

[Thomas Huth]

On 26.03.2018 13:06, Thomas Huth wrote:
> 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

And of course there should also be an "EXIT" before the "THEN" in this
case :-)

 Thomas