NP - Frank Miller's Charlie Brown

[Glenn Scheper]

> sucked terribly at C language

I suck up C.

The key to C in my opinion is to memorize:

	1. the precedence of binding order
	(e.g, multiply/divide before add/subtract before shift before bitwise and/or ...)

	2. whether things are evaluated from left to right, or right to left
	(e.g, math is left to right, but pointers etc. are right to left)


I saw all that printed on the back cover of a small C book years ago. My C grail.

	====

So for instance, in an absurd concoction, nut unlike my real coding:
*p++ += a/-b*2;
unary minus comes before multiply/divide;
multiply/divide comes before assignments;
multiply/divide are of equal binding order,
and evaluated L-to-R, so a/-b comes before that * 2
++ affects p and not *p, per #2.

	====

Back in 1993 I aimed at saving editing keystrokes with terse names:

parse(int i) {
   char * cp = runs + 5;
   int j = 1;
   while (*cp != ' ') {
      j <<= 1;
      j |= *cp++ & 1;
   }
   runs[2] = '\0';
   printf("   0x%04x,\n", j);
   sp[i] = j;
   runs += 19;
   return 0;
}

	====


By 1997 I thought I might be saving a few cpu cycles by avoiding
library calls, like doing all my own atoi and printf conversions,
and I was writing unreadable code using some of my....

//favorite idioms
#define in        *into++ =
#define incrlf    {*(short*)into = '\r' | '\n' << 8; into +=2;}
#define ineol     *into = '\0';
#define ins(x)    {char*cq=x; if((*into = *cq) != '\0') while((*++into = *++cq) != '\0'){}}

char * InTen(char * into, int n, char * text)
{
   //advancing into, format count and text fixing '$'=pluralization
   //input like 7 "  Big ball$ ..."
   //makes output "  Seven big balls ..."
   static char *cardinal[] = {
      "No",
      "One",
      "Two",
      "Three",
      "Four",
      "Five",
      "Six",
      "Seven",
      "Eight",
      "Nine",
      "Ten",
   };
   char *from;
   At(1307);
   if(esc)Ape();        //nobody doing test would be in a very big hurry
   while(*text == ' ') {                     //copy initial spaces
      in*text++;
   }
   if(n < 11 && n > -1) {                    //spell out these numbers
      from = cardinal [n];
      *into = (char) (*from | *text & ' ');  //may convert Seven to lower case
      while((*++into = *++from) != '\0') {
      }
   } else {
      into = InI(into, n);                   //use digits
   }
   in ' ';
   from = text;
   if(*from)
      in (char)(*from++ | ' ');              //lowercase B of Big
   while ((*into = *from) != '\0' && *from != '$') {
      ++into;
      ++from;
   }
   if(*from) {                               //dollar sign
      ++from;
      if(n != 1) {
         if(from[-2] == 's')                 //loss$ -> losses
            in 'e';                          //make plurals
         in 's';                             //make plurals
      }
      while ((*into = *from) != '\0') {
         ++into;
         ++from;
      }
   }
   ineol;
   At(1308);
   if(esc)Ape();
   return into;
}


	====


But now my syntax is simple, and long words
aim to constantly prop up my senix memory:

int Question_RETRAIN_at_DCS( )
{
    if( ! ExhaustedAllDataRatesToTry )
    {
        RecordFact( QUESTION_RETRAIN_ANSWER_IS_YES );
        return 1;
    }
    else
    {
        RecordFact( QUESTION_RETRAIN_ANSWER_IS_NO );
        return 0;
    }
}


... A routine called from only one place, itself simple, verbose:


    case T_30_NODE_D_RESPONSE_TO_DCS_WAS_FTT:

        ExitTestUnhappyAboutCFR( );

        RecordFact( NOTE_THAT_FTT_IS_ALLOWED_HERE );
        // Woe, I never wrote this rx FTT case code.
        if( Question_RETRAIN_at_DCS( )  )
        {
            TryNewDataRateAfterRtnOrCtc = 1; // Oh. Or FTT, I am so forgetful.
            { TightLoops = 0; T30State = T_30_NODE_D_SET_MODE; }
            TransmitCommandCounter = 0; // to enter T_30_NODE_D_SET_MODE
        }
        else
        {
            TransmitCommandCounter = 0; // for DCN signal
            { TightLoops = 0; T30State = T_30_NODE_C_TRANSMIT_DCN; }
        }

        break;


Now, about C++ ....

Yours truly,
Glenn Scheper
http://home.earthlink.net/~glenn_scheper/
glenn_scheper + at + earthlink.net
Copyleft(!) Forward freely.