Alignment of ⎕FIO and ⎕CR

[Dr . Jürgen Sauermann]

    Hi,
      
      I have streamlined the behaviour of ⎕CR and ⎕FIO with respect to help texts.
      
      Both ⎕CR and ⎕FIO now use the same formats for
      listing their sub-functions:
      
    ⎕FIO ⍬ and ⎕CR ⍬ now both display a brief
      explanation of what every (sub-) function does.
    ⎕FIO '' and ⎕CR '' now both show the existing
      syntax variants for every (sub-) function.
      
      The reasons for the different syntax variants is historic,
      explained in the following for ⎕FIO.
      
      Early versions of ⎕FIO had only a few sub-functions
      that were distinguished by
      an axis argument of ⎕FIO. For example, 
      
    Handle ← ⎕FIO[3] Bs
      
      would fopen a file with filename Bs since axis
      argument 3 was the subfunction number (that
      corresponded to the C/C++ libc function fopen). Shortly
      after that the number of sub-functions 
      began to increase from around 10 to currently 60, making the
      numbering scheme more and
      more awkward.
      
      The next step was the APL library 5 FILE_IO which allowed
      the use of strings instead of
      numbers. This library translates function names into function
      numbers, so instead of the
      above function number 3 one could now say:
      
    )COPY 5 FILE_IO
        ...
        Handle ← FIO∆fopen BS
        
      The use of
      function names instead of function numbers was then adopted by GNU APL
      itself, so that one could now, without using FILE_IO, say:
    
    Handle ← ⎕FIO['fopen']
          Bs
      
      Thw final step in this syntax evolution of ⎕FIO was the adoption of the
      recently
      introduced structured variables, which now allows the sub-function
      of ⎕FIO to
      be written like a sub-variable. For example:
    
    Handle ← ⎕FIO.fopen
            Bs
        
      That seems to be the most elegant syntax so far. Same for ⎕CR, except that the
      function number of ⎕CR is the left argument and not
      an axis. For example:
      
    ⎕CR.style_boxed_4 ⊂1 2 3
      
      instead of:
    
    8 ⎕CR ⊂1 2 3
      
      The old formats are still working as before. I should mention,
      that
      the different syntaxes differ slightly in terms of efficiency.
      
      The most efficient syntax (and the one that all others will
      eventually use), is
       the function number syntax.
      
      Next comes the new sub-function syntax (like ⎕CR.style_boxed_4).
      The
      sub-function is tokenized only once and then reused for every
      subfunction call.
      
      The slowest is the old syntax because it uses APL strings instead
      of (faster)
      internal strings) for specifying the desired sub-function.
      
      
      Enjoy,
      Jürgen