* Interface to GiNaC's light-weight expression handles. */
/*
- * GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#define __GINAC_EX_H__
#include <iosfwd>
+#include <iterator>
#include <functional>
+#include <stack>
#include "basic.h"
#include "ptr.h"
class scalar_products;
+class const_iterator;
/** Lightweight wrapper for GiNaC's symbolic objects. Basically all it does is
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:
// 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);
bp.swap(other.bp);
}
+ // iterators
+ const_iterator begin() const throw();
+ const_iterator end() const throw();
+
// evaluation
ex eval(int level = 0) const { return bp->eval(level); }
ex evalf(int level = 0) const { return bp->evalf(level); }
ex lhs() const;
ex rhs() const;
+ // complex conjugation
+ ex conjugate() const { return bp->conjugate(); }
+
// pattern matching
bool has(const ex & pattern) const { return bp->has(pattern); }
bool find(const ex & pattern, lst & found) const;
// rational functions
ex normal(int level = 0) const;
- ex to_rational(lst &repl_lst) const;
- ex to_polynomial(lst &repl_lst) const;
+ ex to_rational(exmap & repl) const;
+ ex to_rational(lst & repl_lst) const;
+ ex to_polynomial(exmap & repl) const;
+ ex to_polynomial(lst & repl_lst) const;
ex numer() const;
ex denom() const;
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;
// indexed objects
exvector get_free_indices() const { return bp->get_free_indices(); }
- ex simplify_indexed() const;
- ex simplify_indexed(const scalar_products & sp) const;
+ ex simplify_indexed(unsigned options = 0) const;
+ ex simplify_indexed(const scalar_products & sp, unsigned options = 0) const;
// comparison
int compare(const ex & other) 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
}
+// Iterators
+
+class const_iterator : public std::iterator<std::random_access_iterator_tag, ex, ptrdiff_t, const ex *, const ex &>
+{
+ friend class ex;
+ friend class const_preorder_iterator;
+ friend class const_postorder_iterator;
+
+public:
+ const_iterator() throw() {}
+
+private:
+ const_iterator(const ex &e_, size_t i_) throw() : e(e_), i(i_) {}
+
+public:
+ // This should return an ex&, but that would be a reference to a
+ // temporary value
+ ex operator*() const
+ {
+ return e.op(i);
+ }
+
+ // This should return an ex*, but that would be a pointer to a
+ // temporary value
+ std::auto_ptr<ex> operator->() const
+ {
+ return std::auto_ptr<ex>(new ex(operator*()));
+ }
+
+ ex operator[](difference_type n) const
+ {
+ return e.op(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(e, i + n);
+ }
+
+ inline friend const_iterator operator+(difference_type n, const const_iterator &it) throw()
+ {
+ return const_iterator(it.e, 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(e, i - n);
+ }
+
+ inline friend difference_type operator-(const const_iterator &lhs, const const_iterator &rhs) throw()
+ {
+ return lhs.i - rhs.i;
+ }
+
+ bool operator==(const const_iterator &other) const throw()
+ {
+ return are_ex_trivially_equal(e, other.e) && 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);
+ }
+
+protected:
+ ex e; // this used to be a "const basic *", but in view of object fusion that wouldn't be safe
+ size_t i;
+};
+
+namespace internal {
+
+struct _iter_rep {
+ _iter_rep(const ex &e_, size_t i_, size_t i_end_) : e(e_), i(i_), i_end(i_end_) {}
+
+ bool operator==(const _iter_rep &other) const throw()
+ {
+ return are_ex_trivially_equal(e, other.e) && i == other.i;
+ }
+
+ bool operator!=(const _iter_rep &other) const throw()
+ {
+ return !(*this == other);
+ }
+
+ ex e;
+ size_t i;
+ size_t i_end;
+};
+
+} // namespace internal
+
+class const_preorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &>
+{
+public:
+ const_preorder_iterator() throw() {}
+
+ // Provide implicit conversion from const_iterator, so ex::begin() and
+ // ex::end() can be used to create const_preorder_iterators
+ const_preorder_iterator(const const_iterator & cit)
+ {
+ s.push(internal::_iter_rep(cit.e, cit.i, cit.e.nops()));
+ }
+
+public:
+ ex operator*() const
+ {
+ return s.top().e;
+ }
+
+ std::auto_ptr<ex> operator->() const
+ {
+ return std::auto_ptr<ex>(new ex(operator*()));
+ }
+
+ const_preorder_iterator &operator++()
+ {
+ increment();
+ return *this;
+ }
+
+ const_preorder_iterator operator++(int)
+ {
+ const_preorder_iterator tmp = *this;
+ increment();
+ return tmp;
+ }
+
+ bool operator==(const const_preorder_iterator &other) const throw()
+ {
+ return s.top() == other.s.top();
+ }
+
+ bool operator!=(const const_preorder_iterator &other) const throw()
+ {
+ return !(*this == other);
+ }
+
+private:
+ std::stack<internal::_iter_rep, std::vector<internal::_iter_rep> > s;
+
+ void increment()
+ {
+ while (s.top().i == s.top().i_end && s.size() > 1) {
+ s.pop();
+ ++s.top().i;
+ }
+
+ internal::_iter_rep & current = s.top();
+
+ if (current.i != current.i_end) {
+ const ex & child = current.e.op(current.i);
+ s.push(internal::_iter_rep(child, 0, child.nops()));
+ }
+ }
+};
+
+class const_postorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &>
+{
+public:
+ const_postorder_iterator() throw() {}
+
+ // Provide implicit conversion from const_iterator, so ex::begin() and
+ // ex::end() can be used to create const_postorder_iterators
+ const_postorder_iterator(const const_iterator & cit)
+ {
+ size_t n = cit.e.nops();
+ if (cit.i != n) {
+ s.push(internal::_iter_rep(cit.e, cit.i, n));
+ descend();
+ }
+ }
+
+public:
+ ex operator*() const
+ {
+ return s.top().e;
+ }
+
+ std::auto_ptr<ex> operator->() const
+ {
+ return std::auto_ptr<ex>(new ex(operator*()));
+ }
+
+ const_postorder_iterator &operator++()
+ {
+ increment();
+ return *this;
+ }
+
+ const_postorder_iterator operator++(int)
+ {
+ const_postorder_iterator tmp = *this;
+ increment();
+ return tmp;
+ }
+
+ bool operator==(const const_postorder_iterator &other) const throw()
+ {
+ return s == other.s;
+ }
+
+ bool operator!=(const const_postorder_iterator &other) const throw()
+ {
+ return !(*this == other);
+ }
+
+private:
+ std::stack<internal::_iter_rep, std::vector<internal::_iter_rep> > s;
+
+ void descend()
+ {
+ while (s.top().i != s.top().i_end) {
+ internal::_iter_rep & current = s.top();
+ const ex & child = current.e.op(current.i);
+ s.push(internal::_iter_rep(child, 0, child.nops()));
+ }
+ }
+
+ void increment()
+ {
+ if (s.top().i == s.top().i_end)
+ s.pop();
+ if (s.size() > 0) {
+ ++s.top().i;
+ descend();
+ }
+ }
+};
+
+inline const_iterator ex::begin() const throw()
+{
+ return const_iterator(*this, 0);
+}
+
+inline const_iterator ex::end() const throw()
+{
+ return const_iterator(*this, nops());
+}
+
+
// utility functions
/** Compare two objects of class quickly without doing a deep tree traversal.
return e1.bp == e2.bp;
}
+/* 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; }
+};
+
+struct ex_is_equal : public std::binary_function<ex, ex, bool> {
+ bool operator() (const ex &lh, const ex &rh) const { return lh.is_equal(rh); }
+};
+
+struct op0_is_equal : public std::binary_function<ex, ex, bool> {
+ bool operator() (const ex &lh, const ex &rh) const { return lh.op(0).is_equal(rh.op(0)); }
+};
+
+struct ex_swap : public std::binary_function<ex, ex, void> {
+ void operator() (ex &lh, ex &rh) const { lh.swap(rh); }
+};
+
// wrapper functions around member functions
inline size_t nops(const ex & thisex)
{ return thisex.nops(); }
inline ex to_rational(const ex & thisex, lst & repl_lst)
{ return thisex.to_rational(repl_lst); }
+inline ex to_rational(const ex & thisex, exmap & repl)
+{ return thisex.to_rational(repl); }
+
+inline ex to_polynomial(const ex & thisex, exmap & repl)
+{ return thisex.to_polynomial(repl); }
+
inline ex to_polynomial(const ex & thisex, lst & repl_lst)
{ return thisex.to_polynomial(repl_lst); }
inline bool match(const ex & thisex, const ex & pattern, lst & repl_lst)
{ return thisex.match(pattern, repl_lst); }
-inline ex simplify_indexed(const ex & thisex)
-{ return thisex.simplify_indexed(); }
+inline ex simplify_indexed(const ex & thisex, unsigned options = 0)
+{ return thisex.simplify_indexed(options); }
-inline ex simplify_indexed(const ex & thisex, const scalar_products & sp)
-{ return thisex.simplify_indexed(sp); }
+inline ex simplify_indexed(const ex & thisex, const scalar_products & sp, unsigned options = 0)
+{ return thisex.simplify_indexed(sp, options); }
inline ex symmetrize(const ex & thisex)
{ return thisex.symmetrize(); }
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; }
-};
-
-struct ex_is_equal : public std::binary_function<ex, ex, bool> {
- bool operator() (const ex &lh, const ex &rh) const { return lh.is_equal(rh); }
-};
-
-struct op0_is_equal : public std::binary_function<ex, ex, bool> {
- bool operator() (const ex &lh, const ex &rh) const { return lh.op(0).is_equal(rh.op(0)); }
-};
-
-struct ex_swap : public std::binary_function<ex, ex, void> {
- void operator() (ex &lh, ex &rh) const { lh.swap(rh); }
-};
-
inline ex ex::subs(const exmap & m, unsigned options) const
{
return bp->subs(m, options);
/** 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.
+ * should generally check the type of e first. Also, you shouldn't cache
+ * the returned reference because GiNaC's garbage collector may destroy
+ * the referenced object any time it's used in another expression.
*
* @param e expression
* @return reference to object of class T
} // 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__