Refactor module static helper functions to helper class.

Functions symbolset and insert_symbols in inifcns.cpp are better written
as a class, to improve readability.

diff --git a/ginac/inifcns.cpp b/ginac/inifcns.cpp
index e2a09b161ccf95ad01e3f95f07b823b79d2b2e54..99959a554920f61d29df1043e0607cfa8776481f 100644 (file)
--- a/ginac/inifcns.cpp
+++ b/ginac/inifcns.cpp
@@ -1038,23 +1038,28 @@ REGISTER_FUNCTION(Order, eval_func(Order_eval).
 // Solve linear system
 //////////
 
-static void insert_symbols(exset &es, const ex &e)
-{
-       if (is_a<symbol>(e)) {
-               es.insert(e);
-       } else {
-               for (const ex &sube : e) {
-                       insert_symbols(es, sube);
+class symbolset {
+       exset s;
+       void insert_symbols(const ex &e)
+       {
+               if (is_a<symbol>(e)) {
+                       s.insert(e);
+               } else {
+                       for (const ex &sube : e) {
+                               insert_symbols(sube);
+                       }
                }
        }
-}
-
-static exset symbolset(const ex &e)
-{
-       exset s;
-       insert_symbols(s, e);
-       return s;
-}
+public:
+       explicit symbolset(const ex &e)
+       {
+               insert_symbols(e);
+       }
+       bool has(const ex &e) const
+       {
+               return s.find(e) != s.end();
+       }
+};
 
 ex lsolve(const ex &eqns, const ex &symbols, unsigned options)
 {
@@ -1095,10 +1100,11 @@ ex lsolve(const ex &eqns, const ex &symbols, unsigned options)
        
        for (size_t r=0; r<eqns.nops(); r++) {
                const ex eq = eqns.op(r).op(0)-eqns.op(r).op(1); // lhs-rhs==0
-               const exset syms = symbolset(eq);
+               const symbolset syms(eq);
                ex linpart = eq;
                for (size_t c=0; c<symbols.nops(); c++) {
-                       if (syms.count(symbols.op(c)) == 0) continue;
+                       if (!syms.has(symbols.op(c)))
+                               continue;
                        const ex co = eq.coeff(ex_to<symbol>(symbols.op(c)),1);
                        linpart -= co*symbols.op(c);
                        sys(r,c) = co;
@@ -1108,13 +1114,13 @@ ex lsolve(const ex &eqns, const ex &symbols, unsigned options)
        }
        
        // test if system is linear and fill vars matrix
-       const exset sys_syms = symbolset(sys);
-       const exset rhs_syms = symbolset(rhs);
+       const symbolset sys_syms(sys);
+       const symbolset rhs_syms(rhs);
        for (size_t i=0; i<symbols.nops(); i++) {
                vars(i,0) = symbols.op(i);
-               if (sys_syms.count(symbols.op(i)) != 0)
+               if (sys_syms.has(symbols.op(i)))
                        throw(std::logic_error("lsolve: system is not linear"));
-               if (rhs_syms.count(symbols.op(i)) != 0)
+               if (rhs_syms.has(symbols.op(i)))
                        throw(std::logic_error("lsolve: system is not linear"));
        }