[Oberon] ReadNum and WriteNum in C

[Frans-Pieter Vonck]

Hi Srinivas,

great fun to give C some Algol swag!

the superfluous ";" in the while loop
can the it be removed by

  #define END    ;}

?
Greets,
F.P.


Srinivas Nayak schreef op 2016-07-09 14:43:
> Dear All,
> 
> Here I tried to implement ReadNum and WriteNum in C.
> I couldn't do it simply using / and % imitating
> how NW has written them using DIV and MOD and Shifts.
> I would like to see a better way to do it...
> 
> 
> #include <stdio.h>
> 
> #define ELSIF  }else if(
> #define ELSE   }else{
> #define IF     if(
> #define THEN   ){
> #define END    }
> #define WHILE  while(
> #define DO     ){
> #define REPEAT do{
> #define UNTIL  }while(!(
> #define RETURN return
> 
> unsigned int ROR(unsigned int x, int n)
> {
> 	return (x >> (n%32))|(x << ((32-n)%32));
> }
> 
> int ASR(int x, int n)
> {
> 	return (x >> n%32);
> }
> 
> void ReadNum(FILE* R, int* x)
> {
>     int y, n;
>     unsigned char b;
>     n = 32; y = 0;
>     b = fgetc(R);
>     //printf("%hhu ", b);
> 
>     WHILE b >= 0x80 DO
> 		y = ROR(y|(b-0x80), 7);
> 		n = n-7;
> 		b = fgetc(R);
> 		//printf("%hhu ", b);
> 	END
> 
> 	//printf("\n");
> 
>     IF n <= 4 THEN
> 		*x = ROR(y|(b&0xF), 4);
> 	ELSE
> 		*x = ASR(ROR(y|b, 7), n-7);
> 	END
> }
> 
> void WriteNum(FILE* R, int x)
> {
> 	unsigned char b;
> 
>     WHILE (x < -0x40) || (x >= 0x40) DO
> 		b = (x & 0x7F)|0x80;
> 		fputc(b, R);
> 		//printf("%hhu ", b);
> 		x = ASR(x, 7);
>     END
> 
> 	b = (x & 0x7F);
>     fputc(b, R);
>     //printf("%hhu ", b);
>     //printf("\n");
> }
> 
> 
> int main()
> {
> 	FILE *f;
> 	int i = 0;
> 	int m = 0, n = 0;
> 
> 	for (i = -8192; i <= 8192; i++)
> 	{
> 		m = i;
> 		//printf("\nnum write = %d\n", m);
> 		f = fopen("test.bin", "wb");
> 		WriteNum(f, m);
> 		fclose(f);
> 
> 		f = fopen("test.bin", "rb");
> 		ReadNum(f, &n);
> 		fclose(f);
> 		//printf("num read = %d\n", n);
> 
> 		if(m != n)
> 		{
> 			printf("%d FAILED\n", m);
> 		}
> 	}
> 
> 	return 0;
> }
> 
> 
> 
> With thanks and best regards,
> 
> Yours sincerely,
> Srinivas Nayak
> 
> Home: http://www.mathmeth.com/sn/
> Blog: http://srinivas-nayak.blogspot.in/
> --
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