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 <
alexey.veretenni...@gmail.com> 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 "
>
>
