first cut at named parameters
[p5sagit/Function-Parameters.git] / Parameters.xs
index 2031f0b..8082d2b 100644 (file)
@@ -62,6 +62,22 @@ WARNINGS_ENABLE
  #define IF_HAVE_PERL_5_16(YES, NO) NO
 #endif
 
+#if 0
+ #if HAVE_PERL_VERSION(5, 17, 6)
+  #error "internal error: missing definition of KEY_my (your perl is too new)"
+ #elif HAVE_PERL_VERSION(5, 15, 8)
+  #define S_KEY_my 134
+ #elif HAVE_PERL_VERSION(5, 15, 6)
+  #define S_KEY_my 133
+ #elif HAVE_PERL_VERSION(5, 15, 5)
+  #define S_KEY_my 132
+ #elif HAVE_PERL_VERSION(5, 13, 0)
+  #define S_KEY_my 131
+ #else
+  #error "internal error: missing definition of KEY_my (your perl is too old)"
+ #endif
+#endif
+
 
 #define MY_PKG "Function::Parameters"
 
@@ -72,19 +88,13 @@ WARNINGS_ENABLE
 
 #define DEFSTRUCT(T) typedef struct T T; struct T
 
-DEFSTRUCT(DefaultParamSpec) {
-       DefaultParamSpec *next;
-       int limit;
-       SV *name;
-       OP *init;
-};
-
 enum {
        FLAG_NAME_OK      = 0x01,
        FLAG_ANON_OK      = 0x02,
        FLAG_DEFAULT_ARGS = 0x04,
        FLAG_CHECK_NARGS  = 0x08,
-       FLAG_INVOCANT     = 0x10
+       FLAG_INVOCANT     = 0x10,
+       FLAG_NAMED_PARAMS = 0x20
 };
 
 DEFSTRUCT(KWSpec) {
@@ -157,12 +167,6 @@ static int kw_flags(pTHX_ const char *kw_ptr, STRLEN kw_len, KWSpec *spec) {
 }
 
 
-static void free_defspec(pTHX_ void *vp) {
-       DefaultParamSpec *dp = vp;
-       op_free(dp->init);
-       Safefree(dp);
-}
-
 static void free_ptr_op(pTHX_ void *vp) {
        OP **pp = vp;
        op_free(*pp);
@@ -181,33 +185,6 @@ static int my_sv_eq_pvn(pTHX_ SV *sv, const char *p, STRLEN n) {
 #include "padop_on_crack.c.inc"
 
 
-#if 0
-static PADOFFSET pad_add_my_sv(SV *name) {
-       PADOFFSET offset;
-       SV *namesv, *myvar;
-       char *p;
-       STRLEN len;
-
-       p = SvPV(name, len);
-       myvar = *av_fetch(PL_comppad, AvFILLp(PL_comppad) + 1, 1);
-       offset = AvFILLp(PL_comppad);
-       SvPADMY_on(myvar);
-       if (*p == '@') {
-               SvUPGRADE(myvar, SVt_PVAV);
-       } else if (*p == '%') {
-               SvUPGRADE(myvar, SVt_PVHV);
-       }
-       PL_curpad = AvARRAY(PL_comppad);
-       namesv = newSV_type(SVt_PVMG);
-       sv_setpvn(namesv, p, len);
-       COP_SEQ_RANGE_LOW_set(namesv, PL_cop_seqmax);
-       COP_SEQ_RANGE_HIGH_set(namesv, PERL_PADSEQ_INTRO);
-       PL_cop_seqmax++;
-       av_store(PL_comppad_name, offset, namesv);
-       return offset;
-}
-#endif
-
 enum {
        MY_ATTR_LVALUE = 0x01,
        MY_ATTR_METHOD = 0x02,
@@ -437,21 +414,341 @@ static void my_check_prototype(pTHX_ const SV *declarator, SV *proto) {
        }
 }
 
+
+DEFSTRUCT(Param) {
+       SV *name;
+       PADOFFSET padoff;
+};
+
+DEFSTRUCT(ParamInit) {
+       Param param;
+       OP *init;
+};
+
+#define VEC(B) B ## _Vec
+
+#define DEFVECTOR(B) DEFSTRUCT(VEC(B)) { \
+       B (*data); \
+       size_t used, size; \
+}
+
+DEFVECTOR(Param);
+DEFVECTOR(ParamInit);
+
+#define DEFVECTOR_INIT(N, B) static void N(VEC(B) *p) { \
+       p->used = 0; \
+       p->size = 23; \
+       Newx(p->data, p->size, B); \
+} static void N(VEC(B) *)
+
+DEFSTRUCT(ParamSpec) {
+       Param invocant;
+       VEC(Param) positional_required;
+       VEC(ParamInit) positional_optional;
+       VEC(Param) named_required;
+       VEC(ParamInit) named_optional;
+       Param slurpy;
+};
+
+DEFVECTOR_INIT(pv_init, Param);
+DEFVECTOR_INIT(piv_init, ParamInit);
+
+static void p_init(Param *p) {
+       p->name = NULL;
+       p->padoff = NOT_IN_PAD;
+}
+
+static void ps_init(ParamSpec *ps) {
+       p_init(&ps->invocant);
+       pv_init(&ps->positional_required);
+       piv_init(&ps->positional_optional);
+       pv_init(&ps->named_required);
+       piv_init(&ps->named_optional);
+       p_init(&ps->slurpy);
+}
+
+#define DEFVECTOR_EXTEND(N, B) static B (*N(VEC(B) *p)) { \
+       assert(p->used <= p->size); \
+       if (p->used == p->size) { \
+               const size_t n = p->size / 2 * 3 + 1; \
+               Renew(p->data, n, B); \
+               p->size = n; \
+       } \
+       return &p->data[p->used]; \
+} static B (*N(VEC(B) *))
+
+DEFVECTOR_EXTEND(pv_extend, Param);
+DEFVECTOR_EXTEND(piv_extend, ParamInit);
+
+#define DEFVECTOR_CLEAR(N, B, F) static void N(pTHX_ VEC(B) *p) { \
+       while (p->used) { \
+               p->used--; \
+               F(aTHX_ &p->data[p->used]); \
+       } \
+       Safefree(p->data); \
+       p->data = NULL; \
+       p->size = 0; \
+} static void N(pTHX_ VEC(B) *)
+
+static void p_clear(pTHX_ Param *p) {
+       p->name = NULL;
+       p->padoff = NOT_IN_PAD;
+}
+
+static void pi_clear(pTHX_ ParamInit *pi) {
+       p_clear(aTHX_ &pi->param);
+       if (pi->init) {
+               op_free(pi->init);
+               pi->init = NULL;
+       }
+}
+
+DEFVECTOR_CLEAR(pv_clear, Param, p_clear);
+DEFVECTOR_CLEAR(piv_clear, ParamInit, pi_clear);
+
+static void ps_clear(pTHX_ ParamSpec *ps) {
+       p_clear(aTHX_ &ps->invocant);
+
+       pv_clear(aTHX_ &ps->positional_required);
+       piv_clear(aTHX_ &ps->positional_optional);
+
+       pv_clear(aTHX_ &ps->named_required);
+       piv_clear(aTHX_ &ps->named_optional);
+
+       p_clear(aTHX_ &ps->slurpy);
+}
+
+static int ps_contains(pTHX_ const ParamSpec *ps, SV *sv) {
+       size_t i, lim;
+
+       if (ps->invocant.name && sv_eq(sv, ps->invocant.name)) {
+               return 1;
+       }
+
+       for (i = 0, lim = ps->positional_required.used; i < lim; i++) {
+               if (sv_eq(sv, ps->positional_required.data[i].name)) {
+                       return 1;
+               }
+       }
+
+       for (i = 0, lim = ps->positional_optional.used; i < lim; i++) {
+               if (sv_eq(sv, ps->positional_optional.data[i].param.name)) {
+                       return 1;
+               }
+       }
+
+       for (i = 0, lim = ps->named_required.used; i < lim; i++) {
+               if (sv_eq(sv, ps->named_required.data[i].name)) {
+                       return 1;
+               }
+       }
+
+       for (i = 0, lim = ps->named_optional.used; i < lim; i++) {
+               if (sv_eq(sv, ps->named_optional.data[i].param.name)) {
+                       return 1;
+               }
+       }
+
+       return 0;
+}
+
+static void ps_free_void(pTHX_ void *p) {
+       ps_clear(aTHX_ p);
+       Safefree(p);
+}
+
+static int args_min(pTHX_ const ParamSpec *ps, const KWSpec *ks) {
+       int n = 0;
+       if (!ps) {
+               return SvTRUE(ks->shift) ? 1 : 0;
+       }
+       if (ps->invocant.name) {
+               n++;
+       }
+       n += ps->positional_required.used;
+       n += ps->named_required.used * 2;
+       return n;
+}
+
+static int args_max(const ParamSpec *ps) {
+       int n = 0;
+       if (!ps) {
+               return -1;
+       }
+       if (ps->invocant.name) {
+               n++;
+       }
+       n += ps->positional_required.used;
+       n += ps->positional_optional.used;
+       if (ps->named_required.used || ps->named_optional.used || ps->slurpy.name) {
+               n = -1;
+       }
+       return n;
+}
+
+static size_t count_positional_params(const ParamSpec *ps) {
+       return ps->positional_required.used + ps->positional_optional.used;
+}
+
+static size_t count_named_params(const ParamSpec *ps) {
+       return ps->named_required.used + ps->named_optional.used;
+}
+
+enum {
+       PARAM_INVOCANT = 0x01,
+       PARAM_NAMED    = 0x02
+};
+
+/* *pinit must be NULL on entry.
+ * caller must free *pinit on error.
+ */
+static PADOFFSET parse_param(
+       pTHX_
+       const SV *declarator, const KWSpec *spec, ParamSpec *param_spec,
+       int *pflags, SV **pname, OP **pinit
+) {
+       I32 c;
+       char sigil;
+       SV *name;
+
+       assert(!*pinit);
+       *pflags = 0;
+
+       c = lex_peek_unichar(0);
+
+       if (c == ':') {
+               lex_read_unichar(0);
+               lex_read_space(0);
+
+               *pflags |= PARAM_NAMED;
+
+               c = lex_peek_unichar(0);
+       }
+
+       if (c == -1) {
+               croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
+       }
+       if (!(c == '$' || c == '@' || c == '%')) {
+               croak("In %"SVf": unexpected '%c' in parameter list (expecting a sigil)", SVfARG(declarator), (int)c);
+       }
+
+       sigil = c;
+
+       lex_read_unichar(0);
+       lex_read_space(0);
+
+       if (!(name = my_scan_word(aTHX_ FALSE))) {
+               croak("In %"SVf": missing identifier after '%c'", SVfARG(declarator), sigil);
+       }
+       sv_insert(name, 0, 0, &sigil, 1);
+       *pname = name;
+
+       lex_read_space(0);
+       c = lex_peek_unichar(0);
+
+       if (c == '=') {
+               lex_read_unichar(0);
+               lex_read_space(0);
+
+
+               if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
+                       param_spec->invocant.name = spec->shift;
+                       param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
+               }
+
+               *pinit = parse_termexpr(0);
+
+               lex_read_space(0);
+               c = lex_peek_unichar(0);
+       }
+
+       if (c == ':') {
+               *pflags |= PARAM_INVOCANT;
+               lex_read_unichar(0);
+               lex_read_space(0);
+       } else if (c == ',') {
+               lex_read_unichar(0);
+               lex_read_space(0);
+       } else if (c != ')') {
+               if (c == -1) {
+                       croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
+               }
+               croak("In %"SVf": unexpected '%c' in parameter list (expecting ',')", SVfARG(declarator), (int)c);
+       }
+
+       return pad_add_name_sv(*pname, IF_HAVE_PERL_5_16(padadd_NO_DUP_CHECK, 0), NULL, NULL);
+}
+
+static OP *my_var_g(pTHX_ I32 type, I32 flags, PADOFFSET padoff) {
+       OP *var = newOP(type, flags);
+       var->op_targ = padoff;
+       return var;
+}
+
+static OP *my_var(pTHX_ I32 flags, PADOFFSET padoff) {
+       return my_var_g(aTHX_ OP_PADSV, flags, padoff);
+}
+
+static SV *mkbits1(pTHX_ size_t n) {
+       size_t bytes = n / 8, bits = n % 8;
+       SV *sv = newSV(bytes + !!bits);
+       char *p = SvPVX(sv), *q = p;
+       while (bytes--) {
+               *p++ = '\xff';
+       }
+       if (bits) {
+               *p++ = (1u << bits) - 1;
+       }
+       *p = '\0';
+       SvCUR_set(sv, p - q);
+       SvPOK_on(sv);
+       return sv;
+}
+
+static OP *mkvecbits(pTHX_ PADOFFSET padoff, size_t i) {
+       OP *first, *mid, *last, *vec;
+
+       last = newSVOP(OP_CONST, 0, newSViv(1));
+       first = last;
+
+       mid = newSVOP(OP_CONST, 0, newSViv(i));
+       mid->op_sibling = first;
+       first = mid;
+
+       mid = my_var(aTHX_ 0, padoff);
+       mid->op_sibling = first;
+
+       first = newOP(OP_PUSHMARK, 0);
+
+       vec = newLISTOP(OP_VEC, 0, first, mid);
+       vec->op_targ = pad_alloc(OP_VEC, SVs_PADTMP);
+       ((LISTOP *)vec)->op_last = last;
+       op_null(((LISTOP *)vec)->op_first);
+
+       return vec;
+}
+
+static OP *mkargselem(pTHX_ OP *index) {
+       OP *args = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
+       args->op_flags |= OPf_REF;
+
+       return newBINOP(OP_AELEM, 0, args, index);
+}
+
+static OP *mkargselemv(pTHX_ PADOFFSET v) {
+       return mkargselem(aTHX_ my_var(aTHX_ 0, v));
+}
+
 static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len, const KWSpec *spec) {
+       ParamSpec *param_spec;
        SV *declarator;
        I32 floor_ix;
        int save_ix;
        SV *saw_name;
        OP **prelude_sentinel;
-       int did_invocant_decl;
-       SV *invocant;
-       AV *params;
-       DefaultParamSpec *defaults;
-       int args_min, args_max;
        SV *proto;
        OP **attrs_sentinel, *body;
        unsigned builtin_attrs;
-       STRLEN len;
        I32 c;
 
        declarator = sv_2mortal(newSVpvn(keyword_ptr, keyword_len));
@@ -502,155 +799,142 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
        SAVEDESTRUCTOR_X(free_ptr_op, prelude_sentinel);
 
        /* parameters */
-       did_invocant_decl = 0;
-       invocant = NULL;
-       params = NULL;
-       defaults = NULL;
-       args_min = 0;
-       args_max = -1;
+       param_spec = NULL;
 
        c = lex_peek_unichar(0);
        if (c == '(') {
-               DefaultParamSpec **pdefaults_tail = &defaults;
-               SV *saw_slurpy = NULL;
-               int param_count = 0;
-               args_max = 0;
+               OP **init_sentinel;
+
+               Newx(init_sentinel, 1, OP *);
+               *init_sentinel = NULL;
+               SAVEDESTRUCTOR_X(free_ptr_op, init_sentinel);
+
+               Newx(param_spec, 1, ParamSpec);
+               ps_init(param_spec);
+               SAVEDESTRUCTOR_X(ps_free_void, param_spec);
 
                lex_read_unichar(0);
                lex_read_space(0);
 
-               params = newAV();
-               sv_2mortal((SV *)params);
+               while ((c = lex_peek_unichar(0)) != ')') {
+                       int flags;
+                       SV *name;
+                       char sigil;
+                       PADOFFSET padoff;
 
-               for (;;) {
-                       c = lex_peek_unichar(0);
-                       if (c == '$' || c == '@' || c == '%') {
-                               const char sigil = c;
-                               SV *param;
+                       padoff = parse_param(aTHX_ declarator, spec, param_spec, &flags, &name, init_sentinel);
 
-                               param_count++;
+                       S_intro_my(aTHX);
 
-                               lex_read_unichar(0);
-                               lex_read_space(0);
+                       sigil = SvPV_nolen(name)[0];
 
-                               if (!(param = my_scan_word(aTHX_ FALSE))) {
-                                       croak("In %"SVf": missing identifier", SVfARG(declarator));
+                       /* internal consistency */
+                       if (flags & PARAM_NAMED) {
+                               if (flags & PARAM_INVOCANT) {
+                                       croak("In %"SVf": invocant %"SVf" can't be a named parameter", SVfARG(declarator), SVfARG(name));
                                }
-                               sv_insert(param, 0, 0, &sigil, 1);
-                               if (saw_slurpy) {
-                                       croak("In %"SVf": I was expecting \")\" after \"%"SVf"\", not \"%"SVf"\"", SVfARG(declarator), SVfARG(saw_slurpy), SVfARG(param));
+                               if (sigil != '$') {
+                                       croak("In %"SVf": named parameter %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
                                }
-                               if (sigil == '$') {
-                                       args_max++;
-                               } else {
-                                       args_max = -1;
-                                       saw_slurpy = param;
+                       } else if (flags & PARAM_INVOCANT) {
+                               if (*init_sentinel) {
+                                       croak("In %"SVf": invocant %"SVf" can't have a default value", SVfARG(declarator), SVfARG(name));
                                }
+                               if (sigil != '$') {
+                                       croak("In %"SVf": invocant %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
+                               }
+                       } else if (sigil != '$' && *init_sentinel) {
+                               croak("In %"SVf": %s %"SVf" can't have a default value", SVfARG(declarator), sigil == '@' ? "array" : "hash", SVfARG(name));
+                       }
 
-                               lex_read_space(0);
-                               c = lex_peek_unichar(0);
-
-                               assert(param_count >= 1);
-
-                               if (c == ':') {
-                                       if (invocant) {
-                                               croak("In %"SVf": invalid double invocants %"SVf", %"SVf"", SVfARG(declarator), SVfARG(invocant), SVfARG(param));
-                                       }
-                                       if (param_count != 1) {
-                                               croak("In %"SVf": invocant %"SVf" must be first in parameter list", SVfARG(declarator), SVfARG(param));
-                                       }
-                                       if (!(spec->flags & FLAG_INVOCANT)) {
-                                               croak("In %"SVf": invocant %"SVf" not allowed here", SVfARG(declarator), SVfARG(param));
-                                       }
-                                       if (sigil != '$') {
-                                               croak("In %"SVf": invocant %"SVf" can't be a %s", SVfARG(declarator), SVfARG(param), sigil == '@' ? "array" : "hash");
-                                       }
-
-                                       lex_read_unichar(0);
-                                       lex_read_space(0);
-
-                                       args_max--;
-                                       param_count--;
-                                       invocant = param;
-                               } else {
-                                       av_push(params, SvREFCNT_inc_simple_NN(param));
-
-                                       if (c == '=' && (spec->flags & FLAG_DEFAULT_ARGS)) {
-                                               DefaultParamSpec *curdef;
-
-                                               if (sigil != '$') {
-                                                       croak("In %"SVf": %s %"SVf" can't have a default value", SVfARG(declarator), sigil == '@' ? "array" : "hash", SVfARG(saw_slurpy));
-                                               }
-
-                                               lex_read_unichar(0);
-                                               lex_read_space(0);
-
-                                               /* my $self;  # in scope for default argument */
-                                               if (!invocant && !did_invocant_decl && SvTRUE(spec->shift)) {
-                                                       OP *var;
-
-                                                       var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
-                                                       var->op_targ = pad_add_name_sv(spec->shift, 0, NULL, NULL);
-
-                                                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
-
-                                                       did_invocant_decl = 1;
-                                               }
-
-                                               Newx(curdef, 1, DefaultParamSpec);
-                                               curdef->next = NULL;
-                                               curdef->limit = param_count;
-                                               curdef->name = param;
-                                               curdef->init = NULL;
-                                               SAVEDESTRUCTOR_X(free_defspec, curdef);
-
-                                               curdef->next = *pdefaults_tail;
-                                               *pdefaults_tail = curdef;
-                                               pdefaults_tail = &curdef->next;
+                       /* external constraints */
+                       if (param_spec->slurpy.name) {
+                               croak("In %"SVf": I was expecting \")\" after \"%"SVf"\", not \"%"SVf"\"", SVfARG(declarator), SVfARG(param_spec->slurpy.name), SVfARG(name));
+                       }
+                       if (sigil != '$') {
+                               assert(!*init_sentinel);
+                               param_spec->slurpy.name = name;
+                               param_spec->slurpy.padoff = padoff;
+                               continue;
+                       }
 
-                                               /* let perl parse the default parameter value */
-                                               curdef->init = parse_termexpr(0);
+                       if (!(flags & PARAM_NAMED) && count_named_params(param_spec)) {
+                               croak("In %"SVf": positional parameter %"SVf" can't appear after named parameter %"SVf"", SVfARG(declarator), SVfARG(name), SVfARG((param_spec->named_required.used ? param_spec->named_required.data[0] : param_spec->named_optional.data[0].param).name));
+                       }
 
-                                               lex_read_space(0);
-                                               c = lex_peek_unichar(0);
-                                       } else {
-                                               if (sigil == '$' && !defaults) {
-                                                       args_min++;
-                                               }
-                                       }
+                       if (flags & PARAM_INVOCANT) {
+                               if (param_spec->invocant.name) {
+                                       croak("In %"SVf": invalid double invocants %"SVf", %"SVf"", SVfARG(declarator), SVfARG(param_spec->invocant.name), SVfARG(name));
+                               }
+                               if (count_positional_params(param_spec) || count_named_params(param_spec)) {
+                                       croak("In %"SVf": invocant %"SVf" must be first in parameter list", SVfARG(declarator), SVfARG(name));
                                }
+                               if (!(spec->flags & FLAG_INVOCANT)) {
+                                       croak("In %"SVf": invocant %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
+                               }
+                               param_spec->invocant.name = name;
+                               param_spec->invocant.padoff = padoff;
+                               continue;
+                       }
 
-                               /* my $param; */
-                               {
-                                       OP *var;
+                       if (*init_sentinel && !(spec->flags & FLAG_DEFAULT_ARGS)) {
+                               croak("In %"SVf": default argument for %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
+                       }
 
-                                       var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
-                                       var->op_targ = pad_add_name_sv(param, 0, NULL, NULL);
+                       if (ps_contains(aTHX_ param_spec, name)) {
+                               croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(name));
+                       }
 
-                                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
+                       if (flags & PARAM_NAMED) {
+                               if (!(spec->flags & FLAG_NAMED_PARAMS)) {
+                                       croak("In %"SVf": named parameter :%"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
                                }
 
-                               if (param_count == 0) {
-                                       continue;
-                               }
+                               if (*init_sentinel) {
+                                       ParamInit *pi = piv_extend(&param_spec->named_optional);
+                                       pi->param.name = name;
+                                       pi->param.padoff = padoff;
+                                       pi->init = *init_sentinel;
+                                       *init_sentinel = NULL;
+                                       param_spec->named_optional.used++;
+                               } else {
+                                       if (param_spec->positional_optional.used) {
+                                               croak("In %"SVf": can't combine optional positional (%"SVf") and required named (%"SVf") parameters", SVfARG(declarator), SVfARG(param_spec->positional_optional.data[0].param.name), SVfARG(name));
+                                       }
 
-                               if (c == ',') {
-                                       lex_read_unichar(0);
-                                       lex_read_space(0);
-                                       continue;
+                                       Param *p = pv_extend(&param_spec->named_required);
+                                       p->name = name;
+                                       p->padoff = padoff;
+                                       param_spec->named_required.used++;
+                               }
+                       } else {
+                               if (*init_sentinel || param_spec->positional_optional.used) {
+                                       ParamInit *pi = piv_extend(&param_spec->positional_optional);
+                                       pi->param.name = name;
+                                       pi->param.padoff = padoff;
+                                       pi->init = *init_sentinel;
+                                       *init_sentinel = NULL;
+                                       param_spec->positional_optional.used++;
+                               } else {
+                                       Param *p = pv_extend(&param_spec->positional_required);
+                                       p->name = name;
+                                       p->padoff = padoff;
+                                       param_spec->positional_required.used++;
                                }
                        }
 
-                       if (c == ')') {
-                               lex_read_unichar(0);
-                               lex_read_space(0);
-                               break;
-                       }
+               }
+               lex_read_unichar(0);
+               lex_read_space(0);
+               *init_sentinel = NULL;
 
-                       if (c == -1) {
-                               croak("In %"SVf": unexpected EOF in parameter list", SVfARG(declarator));
+               if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
+                       if (ps_contains(aTHX_ param_spec, spec->shift)) {
+                               croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(spec->shift));
                        }
-                       croak("In %"SVf": unexpected '%c' in parameter list", SVfARG(declarator), (int)c);
+
+                       param_spec->invocant.name = spec->shift;
+                       param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
                }
        }
 
@@ -772,131 +1056,565 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                CvSPECIAL_on(PL_compcv);
        }
 
-       if (!invocant) {
-               invocant = spec->shift;
+       /* check number of arguments */
+       if (spec->flags & FLAG_CHECK_NARGS) {
+               int amin, amax;
+               size_t named;
 
-               /* my $self;  # wasn't needed yet */
-               if (SvTRUE(invocant) && !did_invocant_decl) {
-                       OP *var;
+               amin = args_min(aTHX_ param_spec, spec);
+               if (amin > 0) {
+                       OP *chk, *cond, *err, *croak;
 
-                       var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
-                       var->op_targ = pad_add_name_sv(invocant, 0, NULL, NULL);
+                       err = newSVOP(OP_CONST, 0,
+                                         newSVpvf("Not enough arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amin));
+                       err = newBINOP(OP_CONCAT, 0,
+                                          err,
+                                          newAVREF(newGVOP(OP_GV, 0, PL_defgv)));
+                       err = newBINOP(OP_CONCAT, 0,
+                                          err,
+                                          newSVOP(OP_CONST, 0, newSVpvs(")")));
 
-                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
-               }
-       }
+                       croak = newCVREF(OPf_WANT_SCALAR,
+                                            newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
+                       err = newUNOP(OP_ENTERSUB, OPf_STACKED,
+                                         op_append_elem(OP_LIST, err, croak));
 
-       /* min/max argument count checks */
-       if (spec->flags & FLAG_CHECK_NARGS) {
-               if (SvTRUE(invocant)) {
-                       args_min++;
-                       if (args_max != -1) {
-                               args_max++;
-                       }
+                       cond = newBINOP(OP_LT, 0,
+                                           newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                           newSVOP(OP_CONST, 0, newSViv(amin)));
+                       chk = newLOGOP(OP_AND, 0, cond, err);
+
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
                }
 
-               if (args_min > 0) {
+               amax = args_max(param_spec);
+               if (amax >= 0) {
                        OP *chk, *cond, *err, *croak;
 
                        err = newSVOP(OP_CONST, 0,
-                                     newSVpvf("Not enough arguments for %"SVf, SVfARG(declarator)));
+                                         newSVpvf("Too many arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amax));
+                       err = newBINOP(OP_CONCAT, 0,
+                                          err,
+                                          newAVREF(newGVOP(OP_GV, 0, PL_defgv)));
+                       err = newBINOP(OP_CONCAT, 0,
+                                          err,
+                                          newSVOP(OP_CONST, 0, newSVpvs(")")));
 
                        croak = newCVREF(OPf_WANT_SCALAR,
-                                        newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
+                                            newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
                        err = newUNOP(OP_ENTERSUB, OPf_STACKED,
-                                     op_append_elem(OP_LIST, err, croak));
+                                         op_append_elem(OP_LIST, err, croak));
 
-                       cond = newBINOP(OP_LT, 0,
-                                       newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
-                                       newSVOP(OP_CONST, 0, newSViv(args_min)));
+                       cond = newBINOP(OP_GT, 0,
+                                           newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                           newSVOP(OP_CONST, 0, newSViv(amax)));
                        chk = newLOGOP(OP_AND, 0, cond, err);
 
                        *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
                }
-               if (args_max != -1) {
+
+               if (param_spec && (count_named_params(param_spec) || (param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%'))) {
                        OP *chk, *cond, *err, *croak;
+                       const UV fixed = count_positional_params(param_spec) + !!param_spec->invocant.name;
 
                        err = newSVOP(OP_CONST, 0,
-                                     newSVpvf("Too many arguments for %"SVf, SVfARG(declarator)));
+                                         newSVpvf("Odd number of paired arguments for %"SVf"", SVfARG(declarator)));
 
                        croak = newCVREF(OPf_WANT_SCALAR,
-                                        newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
+                                            newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
                        err = newUNOP(OP_ENTERSUB, OPf_STACKED,
-                                     op_append_elem(OP_LIST, err, croak));
+                                         op_append_elem(OP_LIST, err, croak));
 
                        cond = newBINOP(OP_GT, 0,
-                                       newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
-                                       newSVOP(OP_CONST, 0, newSViv(args_max)));
+                                           fixed
+                                           ? newBINOP(OP_SUBTRACT, 0,
+                                                      newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                                      newSVOP(OP_CONST, 0, newSVuv(fixed)))
+                                           : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                           newSVOP(OP_CONST, 0, newSViv(0)));
+                       cond = newLOGOP(OP_AND, 0,
+                                           cond,
+                                           newBINOP(OP_MODULO, 0,
+                                                    fixed
+                                                    ? newBINOP(OP_SUBTRACT, 0,
+                                                               newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                                               newSVOP(OP_CONST, 0, newSVuv(fixed)))
+                                                    : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                                    newSVOP(OP_CONST, 0, newSViv(2))));
                        chk = newLOGOP(OP_AND, 0, cond, err);
 
                        *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
                }
        }
 
-       /* $self = shift; */
-       if (SvTRUE(invocant)) {
-               OP *var, *shift;
+       if (!param_spec) {
+               /* my $invocant = shift; */
+               if (SvTRUE(spec->shift)) {
+                       OP *var;
 
-               var = newOP(OP_PADSV, OPf_WANT_SCALAR);
-               var->op_targ = pad_findmy_sv(invocant, 0);
+                       var = my_var(
+                               aTHX_
+                               OPf_MOD | (OPpLVAL_INTRO << 8),
+                               pad_add_name_sv(spec->shift, 0, NULL, NULL)
+                       );
+                       var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
 
-               shift = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
-               *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, shift));
-       }
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
+               }
+       } else {
+               /* my $invocant = shift; */
+               if (param_spec->invocant.name) {
+                       OP *var;
 
-       /* (PARAMS) = @_; */
-       if (params && av_len(params) > -1) {
-               SV *param;
-               OP *init_param, *left, *right;
+                       var = my_var(
+                               aTHX_
+                               OPf_MOD | (OPpLVAL_INTRO << 8),
+                               param_spec->invocant.padoff
+                       );
+                       var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
 
-               left = NULL;
-               while ((param = av_shift(params)) != &PL_sv_undef) {
-                       OP *const var = newOP(OP_PADSV, OPf_WANT_LIST);
-                       var->op_targ = pad_findmy_sv(param, 0);
-                       SvREFCNT_dec(param);
-                       left = op_append_elem(OP_LIST, left, var);
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
                }
 
-               left->op_flags |= OPf_PARENS;
-               right = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
-               init_param = newASSIGNOP(OPf_STACKED, left, 0, right);
-               init_param = newSTATEOP(0, NULL, init_param);
+               /* my (...) = @_; */
+               {
+                       OP *lhs;
+                       size_t i, lim;
 
-               *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, init_param);
-       }
+                       lhs = NULL;
 
-       /* defaults */
-       {
-               OP *gen = NULL;
-               DefaultParamSpec *dp;
+                       for (i = 0, lim = param_spec->positional_required.used; i < lim; i++) {
+                               OP *const var = my_var(
+                                       aTHX_
+                                       OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
+                                       param_spec->positional_required.data[i].padoff
+                               );
+                               lhs = op_append_elem(OP_LIST, lhs, var);
+                       }
 
-               for (dp = defaults; dp; dp = dp->next) {
-                       OP *init = dp->init;
-                       OP *var, *args, *cond;
+                       for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
+                               OP *const var = my_var(
+                                       aTHX_
+                                       OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
+                                       param_spec->positional_optional.data[i].param.padoff
+                               );
+                               lhs = op_append_elem(OP_LIST, lhs, var);
+                       }
 
-                       /* var = `$,name */
-                       var = newOP(OP_PADSV, 0);
-                       var->op_targ = pad_findmy_sv(dp->name, 0);
+                       if (param_spec->slurpy.name) {
+                               if (count_named_params(param_spec)) {
+                                       OP *const var = my_var_g(
+                                               aTHX_
+                                               SvPV_nolen(param_spec->slurpy.name)[0] == '@' ? OP_PADAV : OP_PADHV,
+                                               OPf_MOD | (OPpLVAL_INTRO << 8),
+                                               param_spec->slurpy.padoff
+                                       );
+                                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
+                               } else {
+                                       OP *const var = my_var_g(
+                                               aTHX_
+                                               SvPV_nolen(param_spec->slurpy.name)[0] == '@' ? OP_PADAV : OP_PADHV,
+                                               OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
+                                               param_spec->slurpy.padoff
+                                       );
+                                       lhs = op_append_elem(OP_LIST, lhs, var);
+                               }
+                       }
 
-                       /* init = `,var = ,init */
-                       init = newASSIGNOP(OPf_STACKED, var, 0, init);
+                       if (lhs) {
+                               OP *rhs;
+                               lhs->op_flags |= OPf_PARENS;
+                               rhs = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
+
+                               *prelude_sentinel = op_append_list(
+                                       OP_LINESEQ, *prelude_sentinel,
+                                       newSTATEOP(
+                                               0, NULL,
+                                               newASSIGNOP(OPf_STACKED, lhs, 0, rhs)
+                                       )
+                               );
+                       }
+               }
 
-                       /* args = `@_ */
-                       args = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
+               /* default arguments */
+               {
+                       size_t i, lim, req;
+                       OP *nest;
 
-                       /* cond = `,args < ,index */
-                       cond = newBINOP(OP_LT, 0, args, newSVOP(OP_CONST, 0, newSViv(dp->limit)));
+                       nest = NULL;
 
-                       /* init = `,init if ,cond */
-                       init = newLOGOP(OP_AND, 0, cond, init);
+                       req = param_spec->positional_required.used;
+                       for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
+                               ParamInit *cur = &param_spec->positional_optional.data[i];
+                               OP *var, *cond;
 
-                       /* gen = `,gen ; ,init */
-                       gen = op_append_list(OP_LINESEQ, gen, newSTATEOP(0, NULL, init));
+                               cond = newBINOP(
+                                       OP_LT, 0,
+                                       newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
+                                       newSVOP(OP_CONST, 0, newSViv(req + i + 1))
+                               );
 
-                       dp->init = NULL;
+                               var = my_var(aTHX_ 0, cur->param.padoff);
+
+                               nest = op_append_list(
+                                       OP_LINESEQ, nest,
+                                       newASSIGNOP(OPf_STACKED, var, 0, cur->init)
+                               );
+                               cur->init = NULL;
+                               nest = newCONDOP(
+                                       0,
+                                       cond,
+                                       nest,
+                                       NULL
+                               );
+                       }
+
+                       *prelude_sentinel = op_append_list(
+                               OP_LINESEQ, *prelude_sentinel,
+                               nest
+                       );
                }
 
-               *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, gen);
+               /* named parameters */
+               if (count_named_params(param_spec)) {
+                       int nameblock_ix;
+                       OP *nameblock;
+                       PADOFFSET vb, vc, vi, vk;
+                       const size_t pos = count_positional_params(param_spec);
+
+                       nameblock = NULL;
+                       nameblock_ix = S_block_start(aTHX_ TRUE);
+
+                       {
+                               OP *decl, *var;
+
+                               decl = NULL;
+
+                               if (!param_spec->named_required.used || !(spec->flags & FLAG_CHECK_NARGS)) {
+                                       vb = 0;
+                               } else {
+                                       var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
+                                       var->op_targ = vb = pad_add_name_pvs("$__B", 0, NULL, NULL);
+                                       var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSVpvs("")));
+                                       decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
+                               }
+
+                               if (!param_spec->named_optional.used) {
+                                       vc = 0;
+                               } else {
+                                       var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
+                                       var->op_targ = vc = pad_add_name_pvs("$__C", 0, NULL, NULL);
+                                       var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSVpvs("")));
+                                       decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
+                               }
+
+                               var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
+                               var->op_targ = vk = pad_add_name_pvs("$__K", 0, NULL, NULL);
+                               decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
+
+                               var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
+                               var->op_targ = vi = pad_add_name_pvs("$__I", 0, NULL, NULL);
+                               var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSViv(pos)));
+                               decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
+
+                               //S_intro_my(aTHX);
+                               nameblock = op_append_list(OP_LINESEQ, nameblock, decl);
+                       }
+
+                       {
+                               OP *loop;
+
+                               loop = NULL;
+
+                               loop = op_append_list(
+                                       OP_LINESEQ,
+                                       loop,
+                                       newSTATEOP(
+                                               0, NULL,
+                                               newASSIGNOP(
+                                                       OPf_STACKED,
+                                                       my_var(aTHX_ 0, vk),
+                                                       0,
+                                                       mkargselemv(aTHX_ vi)
+                                               )
+                                       )
+                               );
+
+                               {
+                                       OP *nest;
+                                       size_t i;
+
+                                       if (param_spec->slurpy.name) {
+                                               if (SvPV_nolen(param_spec->slurpy.name)[0] == '@') {
+                                                       OP *first, *mid, *last;
+
+                                                       last = mkargselem(
+                                                               aTHX_
+                                                               newBINOP(
+                                                                       OP_ADD, 0,
+                                                                       my_var(aTHX_ 0, vi),
+                                                                       newSVOP(OP_CONST, 0, newSViv(1))
+                                                               )
+                                                       );
+                                                       mid = last;
+
+                                                       first = my_var(aTHX_ 0, vk);
+                                                       first->op_sibling = mid;
+                                                       mid = first;
+
+                                                       first = my_var_g(aTHX_ OP_PADAV, 0, param_spec->slurpy.padoff);
+                                                       first->op_sibling = mid;
+                                                       mid = first;
+
+                                                       first = newOP(OP_PUSHMARK, 0);
+                                                       nest = newLISTOP(OP_PUSH, 0, first, mid);
+                                                       nest->op_targ = pad_alloc(OP_PUSH, SVs_PADTMP);
+                                                       ((LISTOP *)nest)->op_last = last;
+                                               } else {
+                                                       nest = newASSIGNOP(
+                                                               OPf_STACKED,
+                                                               newBINOP(
+                                                                       OP_HELEM, 0,
+                                                                       my_var_g(aTHX_ OP_PADHV, 0, param_spec->slurpy.padoff),
+                                                                       my_var(aTHX_ 0, vk)
+                                                               ),
+                                                               0,
+                                                               mkargselem(
+                                                                       aTHX_
+                                                                       newBINOP(
+                                                                               OP_ADD, 0,
+                                                                               my_var(aTHX_ 0, vi),
+                                                                               newSVOP(OP_CONST, 0, newSViv(1))
+                                                                       )
+                                                               )
+                                                       );
+                                               }
+                                       } else if (spec->flags & FLAG_CHECK_NARGS) {
+                                               OP *err, *croak;
+
+                                               err = newSVOP(OP_CONST, 0,
+                                                             newSVpvf("In %"SVf": No such named parameter: ", SVfARG(declarator)));
+                                               err = newBINOP(
+                                                       OP_CONCAT, 0,
+                                                       err,
+                                                       my_var(aTHX_ 0, vk)
+                                               );
+
+                                               croak = newCVREF(OPf_WANT_SCALAR,
+                                                                newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
+                                               nest = newUNOP(OP_ENTERSUB, OPf_STACKED,
+                                                              op_append_elem(OP_LIST, err, croak));
+                                       } else {
+                                               nest = NULL;
+                                       }
+
+                                       for (i = param_spec->named_optional.used; i--; ) {
+                                               Param *cur = &param_spec->named_optional.data[i].param;
+                                               size_t dn;
+                                               char *dp = SvPV(cur->name, dn);
+                                               OP *vec;
+
+                                               if (!(spec->flags & FLAG_CHECK_NARGS)) {
+                                                       vec = NULL;
+                                               } else {
+                                                       vec = newASSIGNOP(
+                                                               OPf_STACKED,
+                                                               mkvecbits(aTHX_ vc, i),
+                                                               0,
+                                                               newSVOP(OP_CONST, 0, newSViv(1))
+                                                       );
+                                               }
+
+                                               nest = newCONDOP(
+                                                       0,
+                                                       newBINOP(
+                                                               OP_SEQ, 0,
+                                                               my_var(aTHX_ 0, vk),
+                                                               newSVOP(OP_CONST, 0, newSVpvn_utf8(dp + 1, dn - 1, SvUTF8(cur->name)))
+                                                       ),
+                                                       op_append_list(
+                                                               OP_LINESEQ,
+                                                               newASSIGNOP(
+                                                                       OPf_STACKED,
+                                                                       my_var(aTHX_ 0, cur->padoff),
+                                                                       0,
+                                                                       mkargselem(
+                                                                               aTHX_
+                                                                               newBINOP(
+                                                                                       OP_ADD, 0,
+                                                                                       my_var(aTHX_ 0, vi),
+                                                                                       newSVOP(OP_CONST, 0, newSViv(1))
+                                                                               )
+                                                                       )
+                                                               ),
+                                                               vec
+                                                       ),
+                                                       nest
+                                               );
+                                       }
+
+                                       for (i = param_spec->named_required.used; i--; ) {
+                                               Param *cur = &param_spec->named_required.data[i];
+                                               size_t dn;
+                                               char *dp = SvPV(cur->name, dn);
+                                               OP *vec;
+
+                                               if (!(spec->flags & FLAG_CHECK_NARGS)) {
+                                                       vec = NULL;
+                                               } else {
+                                                       vec = newASSIGNOP(
+                                                               OPf_STACKED,
+                                                               mkvecbits(aTHX_ vb, i),
+                                                               0,
+                                                               newSVOP(OP_CONST, 0, newSViv(1))
+                                                       );
+                                               }
+
+                                               nest = newCONDOP(
+                                                       0,
+                                                       newBINOP(
+                                                               OP_SEQ, 0,
+                                                               my_var(aTHX_ 0, vk),
+                                                               newSVOP(OP_CONST, 0, newSVpvn_utf8(dp + 1, dn - 1, SvUTF8(cur->name)))
+                                                       ),
+                                                       op_append_list(
+                                                               OP_LINESEQ,
+                                                               newASSIGNOP(
+                                                                       OPf_STACKED,
+                                                                       my_var(aTHX_ 0, cur->padoff),
+                                                                       0,
+                                                                       mkargselem(
+                                                                               aTHX_
+                                                                               newBINOP(
+                                                                                       OP_ADD, 0,
+                                                                                       my_var(aTHX_ 0, vi),
+                                                                                       newSVOP(OP_CONST, 0, newSViv(1))
+                                                                               )
+                                                                       )
+                                                               ),
+                                                               vec
+                                                       ),
+                                                       nest
+                                               );
+                                       }
+
+                                       loop = op_append_elem(OP_LINESEQ, loop, newSTATEOP(0, NULL, nest));
+                               }
+
+                               loop = newWHILEOP(
+                                       0, 1,
+                                       NULL,
+                                       newBINOP(
+                                               OP_LT, 0,
+                                               my_var(aTHX_ 0, vi),
+                                               newAVREF(newGVOP(OP_GV, 0, PL_defgv))
+                                       ),
+                                       loop,
+                                       newASSIGNOP(
+                                               OPf_STACKED,
+                                               my_var(aTHX_ 0, vi),
+                                               OP_ADD,
+                                               newSVOP(OP_CONST, 0, newSViv(2))
+                                       ),
+                                       0
+                               );
+
+                               nameblock = op_append_list(OP_LINESEQ, nameblock, newSTATEOP(0, NULL, loop));
+                       }
+
+                       if (param_spec->named_required.used && (spec->flags & FLAG_CHECK_NARGS)) {
+                               OP *cond, *err, *croak, *join;
+
+                               {
+                                       size_t i, lim;
+                                       OP *first, *mid, *last;
+
+                                       last = newNULLLIST();
+                                       mid = last;
+
+                                       for (i = param_spec->named_required.used; i--; ) {
+                                               OP *cur;
+                                               SV *sv = param_spec->named_required.data[i].name;
+                                               size_t n;
+                                               char *p = SvPV(sv, n);
+                                               cur = newCONDOP(
+                                                       0,
+                                                       mkvecbits(aTHX_ vb, i),
+                                                       newNULLLIST(),
+                                                       newSVOP(OP_CONST, 0, newSVpvn_utf8(p + 1, n - 1, SvUTF8(sv)))
+                                               );
+                                               cur->op_sibling = mid;
+                                               mid = cur;
+                                       }
+
+                                       first = newSVOP(OP_CONST, 0, newSVpvs(", "));
+                                       first->op_sibling = mid;
+                                       mid = first;
+
+                                       first = newOP(OP_PUSHMARK, 0);
+
+                                       join = newLISTOP(OP_JOIN, 0, first, mid);
+                                       join->op_targ = pad_alloc(OP_JOIN, SVs_PADTMP);
+                                       ((LISTOP *)join)->op_last = last;
+                               }
+
+                               err = newSVOP(
+                                       OP_CONST, 0,
+                                       newSVpvf("In %"SVf": Missing named parameter(s): ", SVfARG(declarator))
+                               );
+                               err = newBINOP(OP_CONCAT, 0, err, join);
+                               croak = newCVREF(
+                                       OPf_WANT_SCALAR,
+                                       newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
+                               );
+                               err = newUNOP(
+                                       OP_ENTERSUB,
+                                       OPf_STACKED,
+                                       op_append_elem(OP_LIST, err, croak)
+                               );
+                               cond = newBINOP(
+                                       OP_SNE, 0,
+                                       my_var(aTHX_ 0, vb),
+                                       newSVOP(OP_CONST, 0, mkbits1(aTHX_ param_spec->named_required.used))
+                               );
+                               err = newCONDOP(
+                                       0,
+                                       cond,
+                                       err,
+                                       NULL
+                               );
+
+                               nameblock = op_append_list(OP_LINESEQ, nameblock, err);
+                       }
+
+                       if (param_spec->named_optional.used) {
+                               size_t i, lim;
+
+                               for (i = 0, lim = param_spec->named_optional.used; i < lim; i++) {
+                                       ParamInit *const cur = &param_spec->named_optional.data[i];
+                                       OP *init, *cond;
+
+                                       init = newASSIGNOP(
+                                               OPf_STACKED,
+                                               my_var(aTHX_ 0, cur->param.padoff),
+                                               0,
+                                               cur->init
+                                       );
+                                       cur->init = NULL;
+
+                                       cond = newUNOP(OP_NOT, OPf_SPECIAL, mkvecbits(aTHX_ vc, i));
+
+                                       init = newCONDOP(0, cond, init, NULL);
+
+                                       nameblock = op_append_list(OP_LINESEQ, nameblock, newSTATEOP(0, NULL, init));
+                               }
+                       }
+
+                       nameblock = S_block_end(aTHX_ nameblock_ix, nameblock);
+                       nameblock = op_scope(nameblock);
+
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, nameblock);
+               }
        }
 
        /* finally let perl parse the actual subroutine body */
@@ -974,6 +1692,7 @@ WARNINGS_ENABLE {
        newCONSTSUB(stash, "FLAG_DEFAULT_ARGS", newSViv(FLAG_DEFAULT_ARGS));
        newCONSTSUB(stash, "FLAG_CHECK_NARGS",  newSViv(FLAG_CHECK_NARGS));
        newCONSTSUB(stash, "FLAG_INVOCANT",     newSViv(FLAG_INVOCANT));
+       newCONSTSUB(stash, "FLAG_NAMED_PARAMS", newSViv(FLAG_NAMED_PARAMS));
        newCONSTSUB(stash, "HINTK_KEYWORDS", newSVpvs(HINTK_KEYWORDS));
        newCONSTSUB(stash, "HINTK_FLAGS_",   newSVpvs(HINTK_FLAGS_));
        newCONSTSUB(stash, "HINTK_SHIFT_",   newSVpvs(HINTK_SHIFT_));