#define __GINAC_EX_H__
#include <iosfwd>
+#include <iterator>
#include <functional>
#include "basic.h"
class ex
{
friend class archive_node;
- friend bool are_ex_trivially_equal(const ex &, const ex &);
- template<class T> friend const T &ex_to(const ex &);
- template<class T> friend bool is_a(const ex &);
- template<class T> friend bool is_exactly_a(const ex &);
+ friend inline bool are_ex_trivially_equal(const ex &, const ex &);
+ template<class T> friend inline const T &ex_to(const ex &);
+ template<class T> friend inline bool is_a(const ex &);
+ template<class T> friend inline bool is_exactly_a(const ex &);
// default constructor, copy constructor and assignment operator
public:
- ex();
+ ex() throw();
#ifdef OBSCURE_CINT_HACK
ex(const ex & other);
ex & operator=(const ex & other);
* Undefined symbols and other parser errors will throw an exception. */
ex(const std::string &s, const ex &l);
+public:
+ // Iterators
+ class const_iterator : public std::iterator<std::random_access_iterator_tag, ex, ptrdiff_t, const ex *, const ex &>
+ {
+ friend class ex;
+
+ public:
+ const_iterator() throw() {}
+ const_iterator(const basic *bp_, size_t i_) throw() : bp(bp_), i(i_) {}
+
+ bool operator==(const const_iterator &other) const throw()
+ {
+ return bp == other.bp && i == other.i;
+ }
+
+ bool operator!=(const const_iterator &other) const throw()
+ {
+ return !(*this == other);
+ }
+
+ bool operator<(const const_iterator &other) const throw()
+ {
+ return i < other.i;
+ }
+
+ bool operator>(const const_iterator &other) const throw()
+ {
+ return other < *this;
+ }
+
+ bool operator<=(const const_iterator &other) const throw()
+ {
+ return !(other < *this);
+ }
+
+ bool operator>=(const const_iterator &other) const throw()
+ {
+ return !(*this < other);
+ }
+
+ // This should return an ex&, but that would be a reference to a
+ // temporary value
+ ex operator*() const
+ {
+ return bp->op(i);
+ }
+
+#if 0
+ // How do we make this work in the context of the "reference to
+ // temporary" problem? Return an auto_ptr?
+ pointer operator->() const
+ {
+ return &(operator*());
+ }
+#endif
+
+ const_iterator &operator++() throw()
+ {
+ ++i;
+ return *this;
+ }
+
+ const_iterator operator++(int) throw()
+ {
+ const_iterator tmp = *this;
+ ++i;
+ return tmp;
+ }
+
+ const_iterator &operator+=(difference_type n) throw()
+ {
+ i += n;
+ return *this;
+ }
+
+ const_iterator operator+(difference_type n) const throw()
+ {
+ return const_iterator(bp, i + n);
+ }
+
+ inline friend const_iterator operator+(difference_type n, const const_iterator &it) throw()
+ {
+ return const_iterator(it.bp, it.i + n);
+ }
+
+ const_iterator &operator--() throw()
+ {
+ --i;
+ return *this;
+ }
+
+ const_iterator operator--(int) throw()
+ {
+ const_iterator tmp = *this;
+ --i;
+ return tmp;
+ }
+
+ const_iterator &operator-=(difference_type n) throw()
+ {
+ i -= n;
+ return *this;
+ }
+
+ const_iterator operator-(difference_type n) const throw()
+ {
+ return const_iterator(bp, i - n);
+ }
+
+ inline friend difference_type operator-(const const_iterator &lhs, const const_iterator &rhs) throw()
+ {
+ return lhs.i - rhs.i;
+ }
+
+ ex operator[](difference_type n) const
+ {
+ return bp->op(i + n);
+ }
+
+ protected:
+ const basic *bp;
+ size_t i;
+ };
+
+ const_iterator begin() const throw() { return const_iterator(get_pointer(bp), 0); }
+ const_iterator end() const throw() { return const_iterator(get_pointer(bp), bp->nops()); }
+
+#if 0
+ // This doesn't work because of the "reference to temporary" problem
+ // in operator*()
+ typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+ const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); }
+ const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
+#endif
+
// non-virtual functions in this class
public:
/** Efficiently swap the contents of two expressions. */
- void swap(ex & other)
+ void swap(ex & other) throw()
{
GINAC_ASSERT(bp->flags & status_flags::dynallocated);
GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
ex numer_denom() const;
// polynomial algorithms
- ex unit(const symbol &x) const;
- ex content(const symbol &x) const;
+ ex unit(const ex &x) const;
+ ex content(const ex &x) const;
numeric integer_content() const;
- ex primpart(const symbol &x) const;
- ex primpart(const symbol &x, const ex &cont) const;
+ ex primpart(const ex &x) const;
+ ex primpart(const ex &x, const ex &cont) const;
ex smod(const numeric &xi) const { return bp->smod(xi); }
numeric max_coefficient() const;
static basic & construct_from_double(double d);
static ptr<basic> construct_from_string_and_lst(const std::string &s, const ex &l);
void makewriteable();
+ void share(const ex & other) const;
#ifdef OBSCURE_CINT_HACK
public:
// member variables
private:
- ptr<basic> bp; ///< pointer to basic object managed by this
+ mutable ptr<basic> bp; ///< pointer to basic object managed by this
#ifdef OBSCURE_CINT_HACK
public:
extern const basic *_num0_bp;
inline
-ex::ex() : bp(*const_cast<basic *>(_num0_bp))
+ex::ex() throw() : bp(*const_cast<basic *>(_num0_bp))
{
GINAC_ASSERT(bp->flags & status_flags::dynallocated);
#ifdef OBSCURE_CINT_HACK
{
if (bp == other.bp) // trivial case: both expressions point to same basic
return 0;
- return bp->compare(*other.bp);
+ const int cmpval = bp->compare(*other.bp);
+ if (cmpval == 0) {
+ // Expressions point to different, but equal, trees: conserve
+ // memory and make subsequent compare() operations faster by
+ // making both expression point to the same tree.
+ share(other);
+ }
+ return cmpval;
}
inline
inline void swap(ex & e1, ex & e2)
{ e1.swap(e2); }
-
-// This makes STL algorithms use the more efficient swap operation for ex objects
-inline void iter_swap(std::vector<ex>::iterator i1, std::vector<ex>::iterator i2)
-{ i1->swap(*i2); }
-
-
/* Function objects for STL sort() etc. */
struct ex_is_less : public std::binary_function<ex, ex, bool> {
bool operator() (const ex &lh, const ex &rh) const { return lh.compare(rh) < 0; }
return bp->map(fcn);
}
+// convenience type checker template functions
+
+/** Check if ex is a handle to a T, including base classes. */
+template <class T>
+inline bool is_a(const ex &obj)
+{
+ return is_a<T>(*obj.bp);
+}
+
+/** Check if ex is a handle to a T, not including base classes. */
+template <class T>
+inline bool is_exactly_a(const ex &obj)
+{
+ return is_exactly_a<T>(*obj.bp);
+}
+
+/** Return a reference to the basic-derived class T object embedded in an
+ * expression. This is fast but unsafe: the result is undefined if the
+ * expression does not contain a T object at its top level. Hence, you
+ * should generally check the type of e first.
+ *
+ * @param e expression
+ * @return reference to object of class T
+ * @see is_exactly_a<class T>() */
+template <class T>
+inline const T &ex_to(const ex &e)
+{
+ GINAC_ASSERT(is_a<T>(e));
+ return static_cast<const T &>(*e.bp);
+}
} // namespace GiNaC
+
+// Specializations of Standard Library algorithms
+namespace std {
+
+/** Specialization of std::swap() for ex objects. */
+template <>
+inline void swap(GiNaC::ex &a, GiNaC::ex &b)
+{
+ a.swap(b);
+}
+
+/** Specialization of std::iter_swap() for vector<ex> iterators. */
+template <>
+inline void iter_swap(vector<GiNaC::ex>::iterator i1, vector<GiNaC::ex>::iterator i2)
+{
+ i1->swap(*i2);
+}
+
+/** Specialization of std::iter_swap() for list<ex> iterators. */
+template <>
+inline void iter_swap(list<GiNaC::ex>::iterator i1, list<GiNaC::ex>::iterator i2)
+{
+ i1->swap(*i2);
+}
+
+} // namespace std
+
#endif // ndef __GINAC_EX_H__
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