move shared functionality to utility function added to Lepton library

lib/lepton/include/LMP_Lepton.h

@@ -32,6 +32,8 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
  * -------------------------------------------------------------------------- */
 
+#include <string>
+
 #include "lepton/CompiledExpression.h"
 #include "lepton/CustomFunction.h"
 #include "lepton/ExpressionProgram.h"
@@ -40,4 +42,10 @@
 #include "lepton/ParsedExpression.h"
 #include "lepton/Parser.h"
 
+// utility functions
+namespace LMP_Lepton
+{
+  /// remove whitespace and quotes from expression string
+  std::string condense(const std::string &);
+}
 #endif /*LMP_LEPTON_H_*/

lib/lepton/src/Utils.cpp

@@ -0,0 +1,31 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing author: Axel Kohlmeyer (Temple U)
+------------------------------------------------------------------------- */
+
+#include "LMP_Lepton.h"
+
+#include <cctype>
+
+/// remove whitespace and quotes from expression string
+std::string LMP_Lepton::condense(const std::string & in)
+{
+  std::string out;
+  for (const auto &c : in)
+    if (!isspace(c) && (c != '"') && (c != '\'')) out.push_back(c);
+  return out;
+}
+
+

src/LEPTON/bond_lepton.cpp

@@ -24,9 +24,7 @@
 #include "memory.h"
 #include "neighbor.h"
 
-#include <cctype>
 #include <cmath>
-#include <cstring>
 
 #include "LMP_Lepton.h"
 
@@ -170,10 +168,7 @@ void BondLepton::coeff(int narg, char **arg)
 
   // remove whitespace and quotes from expression string and then
   // check if the expression can be parsed and evaluated without error
-  std::string exp_one;
-  for (const auto &c : std::string(arg[2]))
-    if (!isspace(c) && (c != '"') && (c != '\'')) exp_one.push_back(c);
-
+  std::string exp_one = LMP_Lepton::condense(arg[2]);
   try {
     auto parsed = LMP_Lepton::Parser::parse(exp_one);
     auto bondpot = parsed.createCompiledExpression();
@@ -317,6 +312,9 @@ double BondLepton::single(int type, double rsq, int /*i*/, int /*j*/, double &ff
 void *BondLepton::extract(const char *str, int &dim)
 {
   dim = 1;
-  if (strcmp(str, "r0") == 0) return (void *) r0;
+  if (str) {
+    std::string keyword(str);
+    if (keyword == "r0") return (void *) r0;
+  }
   return nullptr;
 }

src/LEPTON/pair_lepton.cpp

@@ -25,9 +25,7 @@
 #include "neigh_list.h"
 #include "update.h"
 
-#include <cctype>
 #include <cmath>
-#include <cstring>
 
 #include "LMP_Lepton.h"
 
@@ -209,10 +207,7 @@ void PairLepton::coeff(int narg, char **arg)
 
   // remove whitespace and quotes from expression string and then
   // check if the expression can be parsed and evaluated without error
-  std::string exp_one;
-  for (const auto &c : std::string(arg[2]))
-    if (!isspace(c) && (c != '"') && (c != '\'')) exp_one.push_back(c);
-
+  std::string exp_one = LMP_Lepton::condense(arg[2]);
   try {
     auto parsed = LMP_Lepton::Parser::parse(exp_one);
     auto pairpot = parsed.createCompiledExpression();