New: callable integers and ranges.

* lib.c (do_generic_funcall): Allow integers and ranges
to be function callable. They take one argument and
index into it or extract a slice. In the case of ranges,
this is a breaking change. Ranges can already be used
in the function position in some limited ways that are
not worth preserving.

* tests/012/callable.tl: New file.

* tests/012/iter.tl: Here we fix two instances of
breakage. Using txr -C 288 will restore the
behaviors previously tested here.

* txr.1: Documented.

1 files changed, 26 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 03e6efb8..086041a0 100644
--- a/lib.c
+++ b/lib.c
@@ -8333,6 +8333,7 @@ INLINE val do_generic_funcall(val fun, struct args *args_in)
   case BUF:
   carray:
   default:
+  dfl:
     bug_unless (args->argc >= ARGS_MIN);
     args_normalize_least(args, 3);
 
@@ -8364,6 +8365,31 @@ INLINE val do_generic_funcall(val fun, struct args *args_in)
       fun = cdr(binding);
     }
     break;
+  case NUM:
+  case BGNUM:
+    args_normalize_least(args, 1);
+
+    switch (args->fill) {
+    case 0:
+      callerror(fun, lit("missing required arguments"));
+    case 1:
+      return ref(args->arg[0], fun);
+    default:
+      callerror(fun, lit("too many arguments"));
+    }
+  case RNG:
+    if (opt_compat && opt_compat <= 288)
+      goto dfl;
+    args_normalize_least(args, 1);
+
+    switch (args->fill) {
+    case 0:
+      callerror(fun, lit("missing required arguments"));
+    case 1:
+      return sub(args->arg[0], fun->rn.from, fun->rn.to);
+    default:
+      callerror(fun, lit("too many arguments"));
+    }
   case COBJ:
     if (fun->co.cls == hash_cls) {
       bug_unless (args->argc >= ARGS_MIN);