- added find() (like has(), but returns list of all occurrences)

[ginac.git] / ginac / ex.cpp

diff --git a/ginac/ex.cpp b/ginac/ex.cpp
index b8a35d3a67c78b98843906ae17b14cda9627c0a5..de48a4f7d7f1557f48d7385e6691d11453a33c3c 100644 (file)
--- a/ginac/ex.cpp
+++ b/ginac/ex.cpp
@@ -115,7 +115,7 @@ void ex::dbgprinttree(void) const
 ex ex::expand(unsigned options) const
 {
        GINAC_ASSERT(bp!=0);
-       if (bp->flags & status_flags::expanded)
+       if (options == 0 && (bp->flags & status_flags::expanded)) // The "expanded" flag only covers the standard options; someone might want to re-expand with different options
                return *bp;
        else
                return bp->expand(options);
@@ -143,6 +143,25 @@ bool ex::match(const ex & pattern) const
        return bp->match(pattern, repl_lst);
 }
 
+/** Find all occurrences of a pattern. The found matches are appended to
+ *  the "found" list. If the expression itself matches the pattern, the
+ *  children are not further examined. This function returns true when any
+ *  matches were found. */
+bool ex::find(const ex & pattern, lst & found) const
+{
+       if (match(pattern)) {
+               found.append(*this);
+               found.sort();
+               found.unique();
+               return true;
+       }
+       bool any_found = false;
+       for (unsigned i=0; i<nops(); i++)
+               if (op(i).find(pattern, found))
+                       any_found = true;
+       return any_found;
+}
+
 ex ex::operator[](const ex & index) const
 {
        debugmsg("ex operator[ex]",LOGLEVEL_OPERATOR);