- ex::series() catches and re-throws exceptions happening during expansion

[ginac.git] / ginac / pseries.cpp

diff --git a/ginac/pseries.cpp b/ginac/pseries.cpp
index 9b6f64a944a788606cd3c11a0ce5f3981fca7087..4faa7200c8551a161fa700ae80c0a5b4c0b09342 100644 (file)
--- a/ginac/pseries.cpp
+++ b/ginac/pseries.cpp
@@ -242,24 +242,47 @@ int pseries::ldegree(const symbol &s) const
 ex pseries::coeff(const symbol &s, int n) const
 {
     if (var.is_equal(s)) {
-        epvector::const_iterator it = seq.begin(), itend = seq.end();
-        while (it != itend) {
-            int pow = ex_to_numeric(it->coeff).to_int();
-            if (pow == n)
-                return it->rest;
-            if (pow > n)
-                return _ex0();
-            it++;
-        }
-        return _ex0();
+               if (seq.size() == 0)
+                       return _ex0();
+
+               // Binary search in sequence for given power
+               numeric looking_for = numeric(n);
+               int lo = 0, hi = seq.size() - 1;
+               while (lo <= hi) {
+                       int mid = (lo + hi) / 2;
+                       GINAC_ASSERT(is_ex_exactly_of_type(seq[mid].coeff, numeric));
+                       int cmp = ex_to_numeric(seq[mid].coeff).compare(looking_for);
+                       switch (cmp) {
+                               case -1:
+                                       lo = mid + 1;
+                                       break;
+                               case 0:
+                                       return seq[mid].rest;
+                               case 1:
+                                       hi = mid - 1;
+                                       break;
+                               default:
+                                       throw(std::logic_error("pseries::coeff: compare() didn't return -1, 0 or 1"));
+                       }
+               }
+               return _ex0();
     } else
         return convert_to_poly().coeff(s, n);
 }
 
+ex pseries::collect(const symbol &s) const
+{
+       return *this;
+}
+
+/** Evaluate coefficients. */
 ex pseries::eval(int level) const
 {
     if (level == 1)
         return this->hold();
+
+       if (level == -max_recursion_level)
+               throw (std::runtime_error("pseries::eval(): recursion limit exceeded"));
     
     // Construct a new series with evaluated coefficients
     epvector new_seq;
@@ -272,10 +295,24 @@ ex pseries::eval(int level) const
     return (new pseries(var, point, new_seq))->setflag(status_flags::dynallocated | status_flags::evaluated);
 }
 
-/** Evaluate numerically.  The order term is dropped. */
+/** Evaluate coefficients numerically. */
 ex pseries::evalf(int level) const
 {
-    return convert_to_poly().evalf(level);
+       if (level == 1)
+               return *this;
+
+       if (level == -max_recursion_level)
+               throw (std::runtime_error("pseries::evalf(): recursion limit exceeded"));
+
+    // Construct a new series with evaluated coefficients
+    epvector new_seq;
+    new_seq.reserve(seq.size());
+    epvector::const_iterator it = seq.begin(), itend = seq.end();
+    while (it != itend) {
+        new_seq.push_back(expair(it->rest.evalf(level-1), it->coeff));
+        it++;
+    }
+    return (new pseries(var, point, new_seq))->setflag(status_flags::dynallocated | status_flags::evaluated);
 }
 
 ex pseries::subs(const lst & ls, const lst & lr) const
@@ -726,7 +763,13 @@ ex pseries::series(const symbol & s, const ex & p, int order) const
 ex ex::series(const symbol &s, const ex &point, int order) const
 {
     GINAC_ASSERT(bp!=0);
-    return bp->series(s, point, order);
+       ex e;
+       try {
+           e = bp->series(s, point, order);
+       } catch (exception &x) {
+               throw (std::logic_error(string("unable to compute series (") + x.what() + ")"));
+       }
+       return e;
 }