Fix crashing example in slicing section

The first example in the slicing section fails to build as it tries to
link the external symbol foo which is not provided.

I also enhanced the other example to be a little bit more interesting
for casual visitors. Examples which display only 'Succeed without
output.' are completely useless.

Author: thewilsonator

spec/arrays.dd

@@ -165,7 +165,10 @@ $(H2 $(LNAME2 slicing, Slicing))
 
 $(SPEC_RUNNABLE_EXAMPLE_COMPILE
 ---------
-void foo(int);
+void foo(int value)
+{
+  writeln("value=", value);
+}
 
 int[10] a;   // declare array of 10 ints
 int[] b;
@@ -182,14 +185,20 @@ foo(b[1]);   // equivalent to foo(3)
         For example, the assignments to b:
         )
 
-$(SPEC_RUNNABLE_EXAMPLE_COMPILE
+$(SPEC_RUNNABLE_EXAMPLE_RUN
 ---------
-int[10] a;
-int[] b;
+int[10] a = [ 1,2,3,4,5,6,7,8,9,10 ];
+int[] b1, b2, b3, b4;
+
+b1 = a;
+b2 = a[];
+b3 = a[0 .. a.length];
+b4 = a[0 .. $];
+writeln(b1);
+writeln(b2);
+writeln(b3);
+writeln(b4);
 
-b = a;
-b = a[];
-b = a[0 .. a.length];
 ---------
 )
 
@@ -201,10 +210,17 @@ b = a[0 .. a.length];
         but for converting pointers into bounds-checked arrays:
         )
 
-$(SPEC_RUNNABLE_EXAMPLE_COMPILE
+$(SPEC_RUNNABLE_EXAMPLE_RUN
 ---------
-int* p;
+int[10] a = [ 1,2,3,4,5,6,7,8,9,10 ];
+
+int* p = &a[2];
 int[] b = p[0..8];
+writeln(b);
+writeln(p[7]);      // 10
+writeln(p[8]);      // undefined behaviour
+writeln(b[7]);      // 10
+//writeln(b[8]);    // range error
 ---------
 )
 

spec/lex.dd

@@ -600,7 +600,7 @@ $(GNAME DecimalInteger):
     $(GLINK NonZeroDigit) $(GLINK DecimalDigitsUS)
 
 $(GNAME BinaryInteger):
-    $(GLINK BinPrefix) $(GLINK BinaryDigitsUS)
+    $(GLINK BinPrefix) $(GLINK BinaryDigitsNoSingleUS)
 
 $(GNAME BinPrefix):
     $(B 0b)
@@ -645,6 +645,12 @@ $(GNAME DecimalDigitUS):
     $(GLINK DecimalDigit)
     $(D _)
 
+$(GNAME BinaryDigitsNoSingleUS):
+    $(GLINK BinaryDigit)
+    $(GLINK BinaryDigit) $(GLINK BinaryDigitsUS)
+    $(GLINK BinaryDigitsUS) $(GLINK BinaryDigit)
+    $(GLINK BinaryDigitsUS) $(GLINK BinaryDigit) $(GLINK BinaryDigitsUS)
+
 $(GNAME BinaryDigitsUS):
     $(GLINK BinaryDigitUS)
     $(GLINK BinaryDigitUS) $(I BinaryDigitsUS)