Add more level words. Rename TOPLEVEL to TOP

[perl/modules/Scope-Upper.git] / Upper.xs

diff --git a/Upper.xs b/Upper.xs
index b2344b9804c0be57573c894ad2080a60e9981cb3..4e2f45f229452b65447d2af2bbfe0ec92c6f92f3 100644 (file)
--- a/Upper.xs
+++ b/Upper.xs
@@ -6,6 +6,8 @@
 #include "perl.h" 
 #include "XSUB.h"
 
+#define __PACKAGE__ "Scope::Upper"
+
 #ifndef SU_DEBUG
 # define SU_DEBUG 0
 #endif
@@ -54,6 +56,10 @@
 # define PERL_MAGIC_env 'E'
 #endif
 
+#ifndef NEGATIVE_INDICES_VAR
+# define NEGATIVE_INDICES_VAR "NEGATIVE_INDICES"
+#endif
+
 #define SU_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
 
 /* --- Stack manipulations ------------------------------------------------- */
@@ -71,29 +77,58 @@
 
 /* ... Saving array elements ............................................... */
 
+STATIC I32 su_av_key2idx(pTHX_ AV *av, I32 key) {
+#define su_av_key2idx(A, K) su_av_key2idx(aTHX_ (A), (K))
+ I32 idx;
+
+ if (key >= 0)
+  return key;
+
+/* Added by MJD in perl-5.8.1 with 6f12eb6d2a1dfaf441504d869b27d2e40ef4966a */
+#if SU_HAS_PERL(5, 8, 1)
+ if (SvRMAGICAL(av)) {
+  const MAGIC * const tied_magic = mg_find((SV *) av, PERL_MAGIC_tied);
+  if (tied_magic) {
+   int adjust_index = 1;
+   SV * const * const negative_indices_glob =
+                    hv_fetch(SvSTASH(SvRV(SvTIED_obj((SV *) (av), tied_magic))),
+                             NEGATIVE_INDICES_VAR, 16, 0);
+   if (negative_indices_glob && SvTRUE(GvSV(*negative_indices_glob)))
+    return key;
+  }
+ }
+#endif
+
+ idx = key + av_len(av) + 1;
+ if (idx < 0)
+  return key;
+
+ return idx;
+}
+
 #ifndef SAVEADELETE
 
 typedef struct {
  AV *av;
- I32 key;
+ I32 idx;
 } su_ud_adelete;
 
 STATIC void su_adelete(pTHX_ void *ud_) {
  su_ud_adelete *ud = ud_;
 
- av_delete(ud->av, ud->key, G_DISCARD);
+ av_delete(ud->av, ud->idx, G_DISCARD);
  SvREFCNT_dec(ud->av);
 
  Safefree(ud);
 }
 
-STATIC void su_save_adelete(pTHX_ AV *av, I32 key) {
+STATIC void su_save_adelete(pTHX_ AV *av, I32 idx) {
 #define su_save_adelete(A, K) su_save_adelete(aTHX_ (A), (K))
  su_ud_adelete *ud;
 
  Newx(ud, 1, su_ud_adelete);
  ud->av  = av;
- ud->key = key;
+ ud->idx = idx;
  SvREFCNT_inc(av);
 
  SAVEDESTRUCTOR_X(su_adelete, ud);
@@ -105,17 +140,19 @@ STATIC void su_save_adelete(pTHX_ AV *av, I32 key) {
 
 STATIC void su_save_aelem(pTHX_ AV *av, SV *key, SV *val) {
 #define su_save_aelem(A, K, V) su_save_aelem(aTHX_ (A), (K), (V))
- I32 idx = SvIV(key);
+ I32 idx;
  I32 preeminent = 1;
  SV **svp;
  HV *stash;
  MAGIC *mg;
 
+ idx = su_av_key2idx(av, SvIV(key));
+
  if (SvCANEXISTDELETE(av))
   preeminent = av_exists(av, idx);
 
  svp = av_fetch(av, idx, 1);
- if (!*svp || *svp == &PL_sv_undef) croak(PL_no_aelem, idx);
+ if (!svp || *svp == &PL_sv_undef) croak(PL_no_aelem, idx);
 
  if (preeminent)
   save_aelem(av, idx, svp);
@@ -485,20 +522,81 @@ done:
  if (level > cxstack_ix) \
   level = cxstack_ix;
 
+#define SU_DOPOPTOCX(t)                    \
+ STMT_START {                              \
+  I32 i, cxix = cxstack_ix, from = 0;      \
+  if (items)                               \
+   from = SvIV(ST(0));                     \
+  for (i = cxix - from; i >= 0; --i) {     \
+   if (CxTYPE(&cxstack[i]) == t) {         \
+    ST(0) = sv_2mortal(newSViv(cxix - i)); \
+    XSRETURN(1);                           \
+   }                                       \
+  }                                        \
+  XSRETURN_UNDEF;                          \
+ } STMT_END
+
 /* --- XS ------------------------------------------------------------------ */
 
 MODULE = Scope::Upper            PACKAGE = Scope::Upper
 
 PROTOTYPES: ENABLE
 
+BOOT:
+{
+ HV *stash = gv_stashpv(__PACKAGE__, 1);
+ newCONSTSUB(stash, "CURRENT", newSViv(0));
+}
+
 SV *
-TOPLEVEL()
+TOP()
 PROTOTYPE:
 CODE:
  RETVAL = newSViv(cxstack_ix);
 OUTPUT:
  RETVAL
 
+SV *
+UP(...)
+PROTOTYPE: ;$
+PREINIT:
+ I32 i = 0;
+ I32 cxix = cxstack_ix;
+CODE:
+ if (items)
+  i = SvIV(ST(0));
+ if (++i > cxix)
+  i = cxix;
+ RETVAL = newSViv(i);
+OUTPUT:
+ RETVAL
+
+SV *
+DOWN(...)
+PROTOTYPE: ;$
+PREINIT:
+ I32 i = 0;
+CODE:
+ if (items)
+  i = SvIV(ST(0));
+ if (--i < 0)
+  i = 0;
+ RETVAL = newSViv(i);
+OUTPUT:
+ RETVAL
+
+void
+SUB(...)
+PROTOTYPE: ;$
+PPCODE:
+ SU_DOPOPTOCX(CXt_SUB);
+
+void
+EVAL(...)
+PROTOTYPE: ;$
+PPCODE:
+ SU_DOPOPTOCX(CXt_EVAL);
+
 void
 reap(SV *hook, ...)
 PROTOTYPE: &;$