Data commit

Task/Extend-your-language/C/extend-your-language-1.c

@@ -0,0 +1,16 @@
+/* Four-way branch.
+ *
+ * if2 (firsttest, secondtest
+ *			, bothtrue
+ *			, firstrue
+ *			, secondtrue
+ *			, bothfalse
+ *	)
+ */
+#define if2(firsttest,secondtest,bothtrue,firsttrue,secondtrue,bothfalse)\
+	switch(((firsttest)?0:2)+((secondtest)?0:1)) {\
+		case 0: bothtrue; break;\
+		case 1: firsttrue; break;\
+		case 2: secondtrue; break;\
+		case 3: bothfalse; break;\
+	}

Task/Extend-your-language/C/extend-your-language-2.c

@@ -0,0 +1,24 @@
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "if2.h"
+
+int main(int argc, char *argv[]) {
+	int i;
+	for (i = 1; i < argc; i++) {
+		char *arg= argv[i], *ep;
+		long lval = strtol(arg, &ep, 10); /* convert arg to long */
+		if2 (arg[0] == '\0', *ep == '\0'
+			, puts("empty string")
+			, puts("empty string")
+			, if2 (lval > 10, lval > 100
+				, printf("%s: a very big number\n", arg)
+				, printf("%s: a big number\n", arg)
+				, printf("%s: a very big number\n", arg)
+				, printf("%s: a number\n", arg)
+			)
+			, printf("%s: not a number\n", arg)
+		)
+	}
+	return 0;
+}

Task/Extend-your-language/C/extend-your-language-3.c

@@ -0,0 +1,9 @@
+$ make exten && ./exten 3 33 333 3a b " " -2
+cc     exten.c   -o exten
+3: a number
+33: a big number
+333: a very big number
+3a: not a number
+b: not a number
+ : not a number
+-2: a number

Task/Extend-your-language/C/extend-your-language-4.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+
+#define if2(a, b) switch(((a)) + ((b)) * 2) { case 3:
+#define else00	break; case 0:	/* both false */
+#define else10	break; case 1:	/* true, false */
+#define else01	break; case 2:	/* false, true */
+#define else2	break; default: /* anything not metioned */
+#define fi2	}		/* stupid end bracket */
+
+int main()
+{
+	int i, j;
+	for (i = 0; i < 3; i++) for (j = 0; j < 3; j++) {
+		printf("%d %d: ", i, j);
+		if2 (i == 1, j == 1)
+			printf("both\n");
+		else10
+			printf("left\n");
+		else01
+			printf("right\n");
+		else00 { /* <-- bracket is optional, flaw */,
+			printf("neither\n");
+			if2 (i == 2, j == 2)
+				printf("\tis 22");
+				printf("\n"); /* flaw: this is part of if2! */
+			else2
+				printf("\tnot 22\n");
+			fi2				
+		}
+		fi2
+	}
+
+	return 0;
+}