Re: wait does not perform as expected

[AdaMagica <christ-usch.grein@t-online.de>]

Niklas Holsti schrieb am Mittwoch, 22. Februar 2023 um 18:36:06 UTC+1:
> On my system, Get_Immediate does /not/ use the inputs collected (but not 
> "consumed") by Look_Ahead, but instead checks if there are _new_ input 
> keystrokes. If there are none, Get_Immediate returns "not Available" 
> (Hit is False) and so the loop continues.

Are you sure? With GNAT Community 2021 (20210519-103) targeting x86_64-w64-mingw32,

  loop
    Look_Ahead    (Char, EoL);  Put ("Look_Ahead:    '" & Char & "', End_of_Line => " & EoL'Image);  New_Line;
    Get_Immediate (Char, Avl);  Put ("Get_Immediate: '" & Char & "', Available   => " & Avl'Image);  New_Line;
  end loop;

I get:

ab x<RETRUN>
Look_Ahead:    'a', End_of_Line => FALSE
Get_Immediate: 'a', Available   => TRUE
Look_Ahead:    'b', End_of_Line => FALSE
Get_Immediate: 'b', Available   => TRUE
Look_Ahead:    ' ', End_of_Line => FALSE
Get_Immediate: ' ', Available   => TRUE
Look_Ahead:    'x', End_of_Line => FALSE
Get_Immediate: 'x', Available   => TRUE
Look_Ahead:    '0', End_of_Line => TRUE
Get_Immediate: '                                          <- This is the EoL
', Available   => TRUE

So Get_Immediate returns the next not yet consumed character. This is inline with A.10.7(12/3):
If a character, either control or graphic, is available from the specified File or the default input file, then the character is read; Available is True and Item contains the value of this character. If a character is not available, then Available is False and the value of Item is not specified.