diff -r c82a45f48bfc -r 5365ef60707e progs/while-arrays/compile_arrays2.sc
--- a/progs/while-arrays/compile_arrays2.sc	Fri Oct 13 23:49:34 2023 +0100
+++ b/progs/while-arrays/compile_arrays2.sc	Sat Oct 21 09:09:09 2023 +0100
@@ -1,5 +1,8 @@
 // A Small Compiler for the WHILE Language
 //
+// - there are some small peep-hole optimisations
+//   implemented
+//
 // - this compiler contains support for "static" integer 
 //   arrays (they are mutable but cannot be re-sized)
 //
@@ -88,11 +91,12 @@
 // convenient string interpolations 
 // for generating instructions and labels
 
-implicit def sring_inters(sc: StringContext) = new {
+extension (sc: StringContext) {
     def i(args: Any*): String = "   " ++ sc.s(args:_*) ++ "\n"
     def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
 }
 
+
 def compile_num(i: Int) = 
   if (0 <= i && i <= 5) i"iconst_$i" else 
   if (-128 <= i && i <= 127) i"bipush $i" else i"ldc $i"
@@ -262,5 +266,3 @@
 
 
 
-
-// runs with amm2 and amm3