Re: [Bug-apl] [PATCH]: allow using lambdas in ]USERCMD

[Alexey Veretennikov]

Hi,

Actually I'm thinking about a patch which will load these usercmds from
the config file at the startup. In this case every user will be
able to create own commands (like ]pwd and ]cd below) to interact with
interpreter and store them independent of the workspaces.

It will definitely helpful for me, what about others?

Christian Robert <address@hidden> writes:

> It would be fun if those ]USERCMD could be saved in workspace  and )loaded 
> back.
>
> Not sure if it's possible ...
>
> Xtian.
>
>
> On 2017-02-23 12:04, Juergen Sauermann wrote:
>> Hi Alexey, Blake,
>>
>> I have applied the patch, *SVN 892*.
>>
>> I don't think that it hurts too much even though its not APL.
>> Nor are lambdas, so the ⍎ of )COMMANDs and {...} should fit nicely.
>>
>> /// Jürgen
>>
>>
>> On 02/23/2017 08:47 AM, Alexey Veretennikov wrote:
>>> Hi,
>>>
>>> I'm updating the ]USERCMD functionality which is already non-standard
>>> extension in GNU
>>> APL. Similar extension exists in Dyalog APL for quite many years as
>>> well. These commands targeted use in the interpreter and have nothing to do
>>> with a new syntax.
>>> What I did is just fixed its limitation where I always had to
>>> create a named function to add a user command.
>>>
>>> P.S. Example with ]pwd was bogus, the proper one is
>>>
>>>       ]usercmd ]pwd {⎕FIO 30 ⍵}
>>>     User-defined command ]pwd installed.
>>>       ]pwd
>>> /Users/alexeyv
>>>
>>>
>>> Blake McBride <address@hidden> writes:
>>>
>>>> Not sure I like this. Doesn't seem like APL. You are mangling
>>>> program-ability with system commands. APL
>>>> has no history of that. It may be an okay idea, but it's not APL.
>>>>
>>>> Adding program-ability to system commands is essentially adding a whole new
>>>> syntax to APL.
>>>>
>>>> Just one opinion.
>>>>
>>>> Blake
>>>>
>>>> On Wed, Feb 22, 2017 at 4:18 PM, Alexey Veretennikov
>>>> <address@hidden> wrote:
>>>>
>>>>  Hi,
>>>>
>>>>  The proposed patch allows usage of dfns as a ]USERCMD.
>>>>  The mode (monadic or dyadic) is not needed since it is derived from the
>>>>  lambda function itself.
>>>>
>>>>  Possibility to use lambdas as a user commands allows to have commands
>>>>  without polluting the global namespace with the function names.
>>>>
>>>>  Usage example:
>>>>
>>>>  ]usercmd ]pwd {⎕FIO 30 ⍵ ← ⍺}
>>>>  User-defined command ]pwd installed.
>>>>
>>>>  ]pwd
>>>>  /Users/alexeyv/Sources/apl-svn/src
>>>>
>>>>  ]usercmd ]cd {⎕FIO[54] (⎕IO+1) ⊃ ⍵ ← ⍺}
>>>>  User-defined command ]cd installed.
>>>>
>>>>  ]cd /Users/alexeyv
>>>>  0
>>>>
>>>>  ]pwd
>>>>  /Users/alexeyv
>>>>
>>>>  --
>>>>  Br,
>>>>  /Alexey
>>>>
>>>>  Index: src/Command.cc
>>>>  ===================================================================
>>>>  --- src/Command.cc (revision 891)
>>>>  +++ src/Command.cc (working copy)
>>>>  @@ -1277,6 +1277,7 @@
>>>>  // ]USERCMD REMOVE ]existing-command
>>>>  // ]USERCMD ]new-command APL-fun
>>>>  // ]USERCMD ]new-command APL-fun mode
>>>>  + // ]USERCMD ]new-command LAMBDA-fun
>>>>  //
>>>>  if (args.size() == 0)
>>>>  {
>>>>  @@ -1321,14 +1322,54 @@
>>>>  return;
>>>>  }
>>>>
>>>>  - if (args.size() > 3)
>>>>  + // check if the user command is not followed by the string
>>>>  + if (args.size() == 1)
>>>>  + {
>>>>  + out << "BAD COMMAND+" << endl;
>>>>  + MORE_ERROR() << "user command syntax in ]USERCMD: ]new-command APL-fun 
>>>> [mode]";
>>>>  + return;
>>>>  + }
>>>>  + UCS_string command_name = args[0];
>>>>  + UCS_string apl_fun = args[1];
>>>>  + int mode = 0;
>>>>  +
>>>>  + // check if lambda
>>>>  + bool is_lambda = false;
>>>>  + if (apl_fun[0] == '{')
>>>>  {
>>>>  + // looks like the user command is a lambda function.
>>>>  + UCS_string result;
>>>>  + // lambdas could contain spaces, collect all arguments in one string
>>>>  + for (int i = 1; i < args.size(); ++ i)
>>>>  + {
>>>>  + result << args[i];
>>>>  + }
>>>>  + // check if lamda-function closed properly
>>>>  + if (result.last() == '}')
>>>>  + {
>>>>  + is_lambda = true;
>>>>  + apl_fun = result;
>>>>  + // determine the mode: if both alpha and omega present, assume dyadic,
>>>>  + // otherwise - monadic usage
>>>>  + mode = (apl_fun.contains(UNI_OMEGA) && apl_fun.contains(UNI_ALPHA)) ? 1 
>>>> : 0;
>>>>  + }
>>>>  + else
>>>>  + {
>>>>  + out << "BAD COMMAND+" << endl;
>>>>  + MORE_ERROR() << "not found closing } in lambda function";
>>>>  + return;
>>>>  + }
>>>>  + }
>>>>  +
>>>>  + if (args.size() > 3 && !is_lambda)
>>>>  + {
>>>>  out << "BAD COMMAND+" << endl;
>>>>  MORE_ERROR() << "too many parameters in command ]USERCMD";
>>>>  return;
>>>>  }
>>>>
>>>>  -const int mode = (args.size() == 3) ? args[2].atoi() : 0;
>>>>  + // check mode
>>>>  + if (!is_lambda && args.size() == 3) mode = args[2].atoi();
>>>>  if (mode < 0 || mode > 1)
>>>>  {
>>>>  out << "BAD COMMAND+" << endl;
>>>>  @@ -1339,11 +1380,11 @@
>>>>
>>>>  // check command name
>>>>  //
>>>>  - loop(c, args[0].size())
>>>>  + loop(c, command_name.size())
>>>>  {
>>>>  bool error = false;
>>>>  - if (c == 0) error = error || args[0][c] != ']';
>>>>  - else error = error || !Avec::is_symbol_char(args[0][c]);
>>>>  + if (c == 0) error = error || command_name[c] != ']';
>>>>  + else error = error || !Avec::is_symbol_char(command_name[c]);
>>>>  if (error)
>>>>  {
>>>>  out << "BAD COMMAND+" << endl;
>>>>  @@ -1355,28 +1396,31 @@
>>>>  // check conflicts with existing commands
>>>>  //
>>>>  #define cmd_def(cmd_str, _cod, _arg, _hint) \
>>>>  - if (check_name_conflict(out, cmd_str, args[0])) return;
>>>>  + if (check_name_conflict(out, cmd_str, command_name)) return;
>>>>  #include "Command.def"
>>>>  - if (check_redefinition(out, args[0], args[1], mode))
>>>>  + if (check_redefinition(out, command_name, apl_fun, mode))
>>>>  {
>>>>  out << " User-defined command "
>>>>  - << args[0] << " installed." << endl;
>>>>  + << command_name << " installed." << endl;
>>>>  return;
>>>>  }
>>>>
>>>>  // check APL function name
>>>>  - //
>>>>  - loop(c, args[1].size())
>>>>  + // Only needed when not a lambda function
>>>>  + if (!is_lambda)
>>>>  {
>>>>  - if (!Avec::is_symbol_char(args[1][c]))
>>>>  - {
>>>>  - out << "BAD COMMAND+" << endl;
>>>>  - MORE_ERROR() << "bad APL function name in command ]USERCMD";
>>>>  - return;
>>>>  - }
>>>>  + loop(c, apl_fun.size())
>>>>  + {
>>>>  + if (!Avec::is_symbol_char(apl_fun[c]))
>>>>  + {
>>>>  + out << "BAD COMMAND+" << endl;
>>>>  + MORE_ERROR() << "bad APL function name in command ]USERCMD";
>>>>  + return;
>>>>  + }
>>>>  + }
>>>>  }
>>>>
>>>>  -user_command new_user_command = { args[0], args[1], mode };
>>>>  +user_command new_user_command = { command_name, apl_fun, mode };
>>>>  user_commands.append(new_user_command);
>>>>
>>>>  out << " User-defined command "
>>>>
>>>>
>>
>

-- 
Br,
/Alexey