15.4.141  src/app/yacc/src/export-parse-fn.pkg

# export-parse-fn.pkg
#
# Top-level entrypoint for mythryl-yacc:
#
# When a user runs mythryl-yacc from the commandline,
# or when a script runs mythryl-yacc, execution conceptually
# starts at parse_fn() below.
#
# 

# Compiled by:
#     src/app/yacc/src/mythryl-yacc.lib



###               "After three days without reading,
###                talk becomes flavorless."
###
###                                -- Chinese proverb



stipulate
    package fil =  file__premicrothread;                                                                        # file__premicrothread          is from   src/lib/std/src/posix/file--premicrothread.pkg
herein

    package   export_parse_fn
    : (weak)
    api {
        parse_fn
            :
            (String, List(String))
            ->
            winix__premicrothread::process::Status;
    }
    {
        fun err msg
            =
            fil::write (fil::stderr, msg);

        include package   trap_control_c;                                                                                       # trap_control_c                is from   src/lib/std/trap-control-c.pkg

        exit =   winix__premicrothread::process::exit;

        fun parse_fn (_, argv)
            =
            {   fun parse_fn' ()
                    =
                    case argv
                        #                  
                        [file] => {   parse_fn::parse_fn file;               exit  winix__premicrothread::process::success; };  # parse_fn                      is from   src/app/yacc/src/link.pkg
                        _      => {   err "Usage: mythryl-yacc filename\n";  exit  winix__premicrothread::process::failure; };
                    esac;

                {   catch_interrupt_signal  parse_fn';                                                          # catch_interrupt_signal        is from   src/lib/std/trap-control-c.pkg
                    #
                    winix__premicrothread::process::success;
                }
                except
                    CONTROL_C_SIGNAL
                        =>
                        winix__premicrothread::process::failure;

                    other_exception
                        =>
                        {   err (string::cat [   "? mythryl-yacc: uncaught exception ",
                                                             exceptions::exception_message  other_exception,
                                                             "\n"
                                                         ]
                                         );

                            winix__premicrothread::process::failure;
                        };
                end;
           };
    };
end;

# Mythryl-Yacc Parser Generator (c) 1991 Andrew W. Appel, David R. Tarditi