Remove usage of IVOS/regexp (#2204)

Replace with `std::regex`

Co-authored-by: Michael Hines <michael.hines@yale.edu>
Co-authored-by: Pramod Kumbhar <pramod.s.kumbhar@gmail.com>

cmake/NeuronFileLists.cmake

@@ -421,7 +421,7 @@ set(NMODL_FILES_LIST
     units.cpp
     version.cpp)
 
-set(IVOS_FILES_LIST observe.cpp regexp.cpp resource.cpp)
+set(IVOS_FILES_LIST observe.cpp resource.cpp)
 
 set(MPI_DYNAMIC_INCLUDE nrnmpi_dynam.h nrnmpi_dynam_cinc nrnmpi_dynam_wrappers.inc)
 

share/lib/hoc/import3d/read_nlcda3.hoc

@@ -545,7 +545,7 @@ proc b2soption_split() {local i, n, id, ip  localobj p, newsec, tobj
 }
 
 proc remove_trailspace() { // yuck
-  hoc_sf_.head(line, " *$", line)
+  hoc_sf_.rtrim(line, line)
   sprint(line, "%s\n", line)
 }
 

src/ivoc/strfun.cpp

@@ -1,10 +1,10 @@
 #include <../../nrnconf.h>
-#include <InterViews/regexp.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include "classreg.h"
 #include "oc2iv.h"
 #include <string.h>
+#include <regex>
 // for alias
 #include <symdir.h>
 #include <oclist.h>
@@ -39,31 +39,52 @@ static double l_len(void*) {
 
 static double l_head(void*) {
     std::string text(gargstr(1));
-    Regexp r(gargstr(2));
-    r.Search(text.c_str(), text.size(), 0, text.size());
-    int i = r.BeginningOfMatch();
-    //	text.set_to_left(i); doesnt work
-    char** head = hoc_pgargstr(3);
-    if (i > 0) {
-        hoc_assign_str(head, text.substr(0, i).c_str());
-    } else {
-        hoc_assign_str(head, "");
+    {  // Clean the text so we keep only the first line
+       // Imitation of std::multiline in our case
+        std::regex r("^(.*)(\n|$)");
+        std::smatch sm;
+        std::regex_search(text, sm, r);
+        text = sm[1];
     }
+    int i = -1;
+    std::string result{};
+    try {
+        std::regex r(gargstr(2), std::regex::egrep);
+        if (std::smatch sm; std::regex_search(text, sm, r)) {
+            i = sm.position();
+            result = sm.prefix().str();
+        }
+    } catch (const std::regex_error& e) {
+        std::cerr << e.what() << std::endl;
+    }
+    char** head = hoc_pgargstr(3);
+    hoc_assign_str(head, result.c_str());
     hoc_return_type_code = 1;  // integer
     return double(i);
 }
 
 static double l_tail(void*) {
     std::string text(gargstr(1));
-    Regexp r(gargstr(2));
-    r.Search(text.c_str(), text.size(), 0, text.size());
-    int i = r.EndOfMatch();
-    char** tail = hoc_pgargstr(3);
-    if (i >= 0) {
-        hoc_assign_str(tail, text.c_str() + i);
-    } else {
-        hoc_assign_str(tail, "");
+    {  // Clean the text so we keep only the first line
+       // Imitation of std::multiline in our case
+        std::regex r("^(.*)(\n|$)");
+        std::smatch sm;
+        std::regex_search(text, sm, r);
+        text = sm[1];
     }
+    int i = -1;
+    std::string result{};
+    try {
+        std::regex r(gargstr(2), std::regex::egrep);
+        if (std::smatch sm; std::regex_search(text, sm, r)) {
+            i = sm.position() + sm.length();
+            result = sm.suffix().str();
+        }
+    } catch (const std::regex_error& e) {
+        std::cerr << e.what() << std::endl;
+    }
+    char** tail = hoc_pgargstr(3);
+    hoc_assign_str(tail, result.c_str());
     hoc_return_type_code = 1;  // integer
     return double(i);
 }

src/ivos/InterViews/_defines.h

@@ -217,7 +217,6 @@
 #define Raster _lib_iv(Raster)
 #define RasterRep _lib_iv(RasterRep)
 #define Reducer _lib_iv(Reducer)
-#define Regexp _lib_iv(Regexp)
 #define ReqErr _lib_iv(ReqErr)
 #define Requirement _lib_iv(Requirement)
 #define Requisition _lib_iv(Requisition)

src/ivos/InterViews/_undefs.h

@@ -217,7 +217,6 @@
 #undef Raster
 #undef RasterRep
 #undef Reducer
-#undef Regexp
 #undef ReqErr
 #undef Requirement
 #undef Requisition