Add .size() to the SectionList object, returns the number of sections in the list (#3520)

* used `.size()` to match what is in Vector()

* add src/nrnoc/seclist.h

* switch to static_cast in src/nrnoc/seclist.cpp

Author: mgeplf

cmake/NeuronFileLists.cmake

@@ -33,6 +33,7 @@ set(HEADER_FILES_TO_INSTALL
     nrnoc/nrnredef.h
     nrnoc/nrnversionmacros.h
     nrnoc/options.h
+    nrnoc/seclist.h
     nrnoc/section_fwd.hpp
     nrnoc/treeset.h
     oc/classreg.h

docs/hoc/modelspec/programmatic/topology/seclist.rst

@@ -165,3 +165,12 @@ SectionList
         ``forsec sectionlist {statement}``
 
 
+.. hoc:method:: SectionList.size
+
+
+    Syntax:
+        ``.size()``
+
+
+    Description:
+        Returns the number of sections in the list.

docs/python/modelspec/programmatic/topology/seclist.rst

@@ -234,3 +234,16 @@ SectionList
                 print(sec)
          
 
+----
+
+
+
+.. method:: SectionList.size
+
+
+    Syntax:
+        ``.size()``
+
+
+    Description:
+        Returns the number of sections in the list.

src/nrnoc/init.cpp

@@ -11,6 +11,7 @@
 #include <unistd.h>
 #endif
 #include "section.h"
+#include "seclist.h"  // SectionList_reg
 #include "parse.hpp"
 #include "nrniv_mf.h"
 #include "cabvars.h"

src/nrnoc/nrn_ansi.h

@@ -3,6 +3,7 @@
 #include "membfunc.h"  // nrn_bamech_t
 #include "cabcode.h"
 #include "neuron/container/data_handle.hpp"
+#include "seclist.h"
 #include "neuron/container/generic_data_handle.hpp"
 #include <memory>
 
@@ -82,7 +83,6 @@ void long_difus_solve(neuron::model_sorted_token const&, int method, NrnThread&
 extern void nrn_fihexec(int);
 extern int special_pnt_call(Object*, Symbol*, int);
 extern void nrn_mk_prop_pools(int);
-extern void SectionList_reg(void);
 extern void SectionRef_reg(void);
 
 extern void hoc_symbol_tolerance(Symbol*, double);
@@ -129,7 +129,6 @@ extern void recalc_diam(void);
 extern bool nrn_use_fast_imem;
 void nrn_fast_imem_alloc();
 extern void nrn_calc_fast_imem(NrnThread*);
-extern Section* nrn_secarg(int iarg);
 extern void nrn_seg_or_x_arg(int iarg, Section** psec, double* px);
 extern void nrn_seg_or_x_arg2(int iarg, Section** psec, double* px);
 extern Section* nrnpy_pysecname2sec(const char*);

src/nrnoc/seclist.cpp

@@ -1,7 +1,5 @@
 #include <../../nrnconf.h>
 
-#include <functional>
-
 #define HOC_L_LIST 1
 #include "section.h"
 #include "neuron.h"
@@ -63,7 +61,7 @@ static void* constructor(Object* ho) {
 
 static void destructor(void* v) {
     Item* q;
-    List* sl = (List*) v;
+    List* sl = static_cast<List*>(v);
     ITERATE(q, sl) {
         section_unref(q->element.sec);
     }
@@ -97,10 +95,8 @@ static void children1(List* sl, Section* sec) {
 }
 
 static double children(void* v) {
-    Section* sec;
-    List* sl;
-    sec = nrn_secarg(1);
-    sl = (List*) v;
+    Section* sec = nrn_secarg(1);
+    List* sl = static_cast<List*>(v);
     children1(sl, sec);
     return 1.;
 }
@@ -121,17 +117,15 @@ static void subtree1(List* sl, Section* sec) {
 }
 
 static double subtree(void* v) {
-    Section* sec;
-    List* sl;
-    sec = nrn_secarg(1);
-    sl = (List*) v;
+    Section* sec = nrn_secarg(1);
+    List* sl = static_cast<List*>(v);
     subtree1(sl, sec);
     return 1.;
 }
 
 static double wholetree(void* v) {
     Section* sec = nrn_secarg(1);
-    List* sl = (List*) v;
+    List* sl = static_cast<List*>(v);
     /*find root*/
     Section* s = nullptr;
     for (s = sec; s->parentsec; s = s->parentsec) {
@@ -142,10 +136,8 @@ static double wholetree(void* v) {
 }
 
 static double allroots(void* v) {
-    List* sl;
+    List* sl = static_cast<List*>(v);
     Item* qsec;
-    sl = (List*) v;
-    // ForAllSections(sec)
     ITERATE(qsec, section_list) {
         Section* sec = hocSEC(qsec);
         if (!sec->parentsec) {
@@ -158,7 +150,7 @@ static double allroots(void* v) {
 }
 
 static double seclist_remove(void* v) {
-    List* sl = (List*) v;
+    List* sl = static_cast<List*>(v);
     int i = 0;
 #if USE_PYTHON
     if (!ifarg(1) || (*hoc_objgetarg(1))->ctemplate->sym == nrnpy_pyobj_sym_) {
@@ -182,9 +174,9 @@ static double seclist_remove(void* v) {
         o = *hoc_objgetarg(1);
         check_obj_type(o, "SectionList");
         seclist_iterate_remove(sl, [](Section* s) { s->volatile_mark = 0; });
-        sl = (List*) o->u.this_pointer;
+        sl = static_cast<List*>(o->u.this_pointer);
         seclist_iterate_remove(sl, [](Section* s) { s->volatile_mark = 1; });
-        sl = (List*) v;
+        sl = static_cast<List*>(v);
         Item* q1;
         for (Item* q = sl->next; q != sl; q = q1) {
             q1 = q->next;
@@ -200,8 +192,8 @@ static double seclist_remove(void* v) {
 }
 
 static double unique(void* v) {
-    Item* q1;
-    List* sl = (List*) v;
+    Item* q1 = nullptr;
+    List* sl = static_cast<List*>(v);
     hoc_return_type_code = 1; /* integer */
     seclist_iterate_remove(sl, [](Section* s) { s->volatile_mark = 0; });
     int i = 0; /* number deleted */
@@ -218,7 +210,7 @@ static double unique(void* v) {
 }
 
 static double contains(void* v) {
-    List* sl = (List*) v;
+    List* sl = static_cast<List*>(v);
     hoc_return_type_code = 2; /* boolean */
     Section* s = nrn_secarg(1);
     return seclist_iterate_remove_until(
@@ -228,7 +220,7 @@ static double contains(void* v) {
 }
 
 static double printnames(void* v) {
-    List* sl = (List*) v;
+    List* sl = static_cast<List*>(v);
     seclist_iterate_remove(sl, [](Section* s) {
         if (s->prop) {
             Printf("%s\n", secname(s));
@@ -237,6 +229,15 @@ static double printnames(void* v) {
     return 1.;
 }
 
+double seclist_size(void* v) {
+    double count = 0.;
+    List* sl = static_cast<List*>(v);
+    for (Item* q1 = sl->next; q1 != sl; q1 = q1->next) {
+        count++;
+    }
+    return count;
+}
+
 static Member_func members[] = {{"append", append},
                                 {"remove", seclist_remove},
                                 {"wholetree", wholetree},
@@ -246,6 +247,7 @@ static Member_func members[] = {{"append", append},
                                 {"printnames", printnames},
                                 {"contains", contains},
                                 {"allroots", allroots},
+                                {"size", seclist_size},
                                 {nullptr, nullptr}};
 
 void SectionList_reg(void) {
@@ -265,28 +267,24 @@ static void check(Object* ob) {
     }
 }
 
-void forall_sectionlist(void) {
-    Inst* savepc = pc;
-    Item *q, *q1;
-    Section* sec;
-    List* sl;
-    Object* ob;
-    Object** obp;
-    int istk;
-
+void forall_sectionlist() {
     /* if arg is a string use forall_section */
     if (hoc_stacktype() == STRING) {
         forall_section();
         return;
     }
-    obp = hoc_objpop();
-    ob = *obp;
+
+    Inst* savepc = pc;
+    Object** obp = hoc_objpop();
+    Object* ob = *obp;
     check(ob);
-    sl = (List*) (ob->u.this_pointer);
-    istk = nrn_isecstack();
-    for (q = sl->next; q != sl; q = q1) {
+    List* sl = static_cast<List*>(ob->u.this_pointer);
+    int istk = nrn_isecstack();
+
+    Item* q1;
+    for (Item* q = sl->next; q != sl; q = q1) {
         q1 = q->next;
-        sec = q->element.sec;
+        Section* sec = q->element.sec;
         if (!sec->prop) {
             hoc_l_delete(q);
             section_unref(sec);
@@ -313,19 +311,19 @@ void forall_sectionlist(void) {
     }
 }
 
-void hoc_ifseclist(void) {
-    Inst* savepc = pc;
-    Section* sec = chk_access();
-
+void hoc_ifseclist() {
     /* if arg is a string use forall_section */
     if (hoc_stacktype() == STRING) {
         hoc_ifsec();
         return;
     }
+
+    Inst* savepc = pc;
+    Section* sec = chk_access();
     Object** obp = hoc_objpop();
     Object* ob = *obp;
     check(ob);
-    List* sl = (List*) (ob->u.this_pointer);
+    List* sl = static_cast<List*>(ob->u.this_pointer);
     if (seclist_iterate_remove_until(
             sl,
             [&](Item*) {

src/nrnoc/seclist.h

@@ -0,0 +1,10 @@
+#pragma once
+
+struct Section;
+
+void SectionList_reg(void);
+void lvappendsec_and_ref(void* sl, Section* sec);
+Section* nrn_secarg(int iarg);
+double seclist_size(void* sl);
+void forall_sectionlist();
+void hoc_ifseclist();

src/nrnpython/nrnpy_hoc.cpp

@@ -15,6 +15,7 @@
 #include "ocjump.h"
 #include "oclist.h"
 #include "shapeplt.h"
+#include "seclist.h"  // lvappendsec_and_ref, seclist_size
 
 #include <cstdint>
 #include <vector>
@@ -34,7 +35,6 @@ extern void (*nrnpy_restore_savestate)(int64_t, char*);
 extern void (*nrnpy_store_savestate)(char** save_data, uint64_t* save_data_size);
 extern void (*nrnpy_decref)(void* pyobj);
 extern double (*nrnpy_call_func)(Object*, double);
-extern void lvappendsec_and_ref(void* sl, Section* sec);
 extern void hoc_pushs(Symbol*);
 extern double* hoc_evalpointer();
 extern double cable_prop_eval(Symbol* sym);
@@ -1639,12 +1639,7 @@ static int araychk(Arrayinfo* a, PyHocObject* po, int ix) {
 
 static Py_ssize_t seclist_count(Object* ho) {
     assert(ho->ctemplate == hoc_sectionlist_template_);
-    hoc_List* sl = (hoc_List*) (ho->u.this_pointer);
-    Py_ssize_t n = 0;
-    for (hoc_Item* q1 = sl->next; q1 != sl; q1 = q1->next) {
-        n++;
-    }
-    return n;
+    return static_cast<Py_ssize_t>(seclist_size(static_cast<hoc_List*>(ho->u.this_pointer)));
 }
 
 static Py_ssize_t hocobj_len(PyObject* self) {