/** @file ex.cpp
*
* Implementation of GiNaC's light-weight expression handles. */
/*
* GiNaC Copyright (C) 1999-2007 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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <iostream>
#include <stdexcept>
#include "ex.h"
#include "add.h"
#include "mul.h"
#include "ncmul.h"
#include "numeric.h"
#include "power.h"
#include "lst.h"
#include "relational.h"
#include "input_lexer.h"
#include "utils.h"
namespace GiNaC {
//////////
// other constructors
//////////
// none (all inlined)
//////////
// non-virtual functions in this class
//////////
// public
/** Print expression to stream. The formatting of the output is determined
* by the kind of print_context object that is passed. Possible formattings
* include ginsh-parsable output (the default), tree-like output for
* debugging, and C++ source.
* @see print_context */
void ex::print(const print_context & c, unsigned level) const
{
bp->print(c, level);
}
/** Little wrapper arount print to be called within a debugger. */
void ex::dbgprint() const
{
bp->dbgprint();
}
/** Little wrapper arount printtree to be called within a debugger. */
void ex::dbgprinttree() const
{
bp->dbgprinttree();
}
ex ex::expand(unsigned options) const
{
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 *this;
else
return bp->expand(options);
}
/** Compute partial derivative of an expression.
*
* @param s symbol by which the expression is derived
* @param nth order of derivative (default 1)
* @return partial derivative as a new expression */
ex ex::diff(const symbol & s, unsigned nth) const
{
if (!nth)
return *this;
else
return bp->diff(s, nth);
}
/** Check whether expression matches a specified pattern. */
bool ex::match(const ex & pattern) const
{
lst repl_lst;
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 (size_t i=0; i<nops(); i++)
if (op(i).find(pattern, found))
any_found = true;
return any_found;
}
/** Substitute objects in an expression (syntactic substitution) and return
* the result as a new expression. */
ex ex::subs(const lst & ls, const lst & lr, unsigned options) const
{
GINAC_ASSERT(ls.nops() == lr.nops());
// Convert the lists to a map
exmap m;
for (lst::const_iterator its = ls.begin(), itr = lr.begin(); its != ls.end(); ++its, ++itr) {
m.insert(std::make_pair(*its, *itr));
// Search for products and powers in the expressions to be substituted
// (for an optimization in expairseq::subs())
if (is_exactly_a<mul>(*its) || is_exactly_a<power>(*its))
options |= subs_options::pattern_is_product;
}
if (!(options & subs_options::pattern_is_product))
options |= subs_options::pattern_is_not_product;
return bp->subs(m, options);
}
/** Substitute objects in an expression (syntactic substitution) and return
* the result as a new expression. There are two valid types of
* replacement arguments: 1) a relational like object==ex and 2) a list of
* relationals lst(object1==ex1,object2==ex2,...). */
ex ex::subs(const ex & e, unsigned options) const
{
if (e.info(info_flags::relation_equal)) {
// Argument is a relation: convert it to a map
exmap m;
const ex & s = e.op(0);
m.insert(std::make_pair(s, e.op(1)));
if (is_exactly_a<mul>(s) || is_exactly_a<power>(s))
options |= subs_options::pattern_is_product;
else
options |= subs_options::pattern_is_not_product;
return bp->subs(m, options);
} else if (e.info(info_flags::list)) {
// Argument is a list: convert it to a map
exmap m;
GINAC_ASSERT(is_a<lst>(e));
for (lst::const_iterator it = ex_to<lst>(e).begin(); it != ex_to<lst>(e).end(); ++it) {
ex r = *it;
if (!r.info(info_flags::relation_equal))
throw(std::invalid_argument("basic::subs(ex): argument must be a list of equations"));
const ex & s = r.op(0);
m.insert(std::make_pair(s, r.op(1)));
// Search for products and powers in the expressions to be substituted
// (for an optimization in expairseq::subs())
if (is_exactly_a<mul>(s) || is_exactly_a<power>(s))
options |= subs_options::pattern_is_product;
}
if (!(options & subs_options::pattern_is_product))
options |= subs_options::pattern_is_not_product;
return bp->subs(m, options);
} else
throw(std::invalid_argument("ex::subs(ex): argument must be a relation_equal or a list"));
}
/** Traverse expression tree with given visitor, preorder traversal. */
void ex::traverse_preorder(visitor & v) const
{
accept(v);
size_t n = nops();
for (size_t i = 0; i < n; ++i)
op(i).traverse_preorder(v);
}
/** Traverse expression tree with given visitor, postorder traversal. */
void ex::traverse_postorder(visitor & v) const
{
size_t n = nops();
for (size_t i = 0; i < n; ++i)
op(i).traverse_postorder(v);
accept(v);
}
/** Return modifyable operand/member at position i. */
ex & ex::let_op(size_t i)
{
makewriteable();
return bp->let_op(i);
}
ex & ex::operator[](const ex & index)
{
makewriteable();
return (*bp)[index];
}
ex & ex::operator[](size_t i)
{
makewriteable();
return (*bp)[i];
}
/** Left hand side of relational expression. */
ex ex::lhs() const
{
if (!is_a<relational>(*this))
throw std::runtime_error("ex::lhs(): not a relation");
return bp->op(0);
}
/** Right hand side of relational expression. */
ex ex::rhs() const
{
if (!is_a<relational>(*this))
throw std::runtime_error("ex::rhs(): not a relation");
return bp->op(1);
}
// private
/** Make this ex writable (if more than one ex handle the same basic) by
* unlinking the object and creating an unshared copy of it. */
void ex::makewriteable()
{
GINAC_ASSERT(bp->flags & status_flags::dynallocated);
bp.makewritable();
GINAC_ASSERT(bp->get_refcount() == 1);
}
/** Share equal objects between expressions.
* @see ex::compare(const ex &) */
void ex::share(const ex & other) const
{
if ((bp->flags | other.bp->flags) & status_flags::not_shareable)
return;
if (bp->get_refcount() <= other.bp->get_refcount())
bp = other.bp;
else
other.bp = bp;
}
/** Helper function for the ex-from-basic constructor. This is where GiNaC's
* automatic evaluator and memory management are implemented.
* @see ex::ex(const basic &) */
ptr<basic> ex::construct_from_basic(const basic & other)
{
if (!(other.flags & status_flags::evaluated)) {
// The object is not yet evaluated, so call eval() to evaluate
// the top level. This will return either
// a) the original object with status_flags::evaluated set (when the
// eval() implementation calls hold())
// or
// b) a different expression.
//
// eval() returns an ex, not a basic&, so this will go through
// construct_from_basic() a second time. In case a) we end up in
// the "else" branch below. In case b) we end up here again and
// apply eval() once more. The recursion stops when eval() calls
// hold() or returns an object that already has its "evaluated"
// flag set, such as a symbol or a numeric.
const ex & tmpex = other.eval(1);
// Eventually, the eval() recursion goes through the "else" branch
// below, which assures that the object pointed to by tmpex.bp is
// allocated on the heap (either it was already on the heap or it
// is a heap-allocated duplicate of another object).
GINAC_ASSERT(tmpex.bp->flags & status_flags::dynallocated);
// If the original object is not referenced but heap-allocated,
// it means that eval() hit case b) above. The original object is
// no longer needed (it evaluated into something different), so we
// delete it (because nobody else will).
if ((other.get_refcount() == 0) && (other.flags & status_flags::dynallocated))
delete &other; // yes, you can apply delete to a const pointer
// We can't return a basic& here because the tmpex is destroyed as
// soon as we leave the function, which would deallocate the
// evaluated object.
return tmpex.bp;
} else {
// The easy case: making an "ex" out of an evaluated object.
if (other.flags & status_flags::dynallocated) {
// The object is already heap-allocated, so we can just make
// another reference to it.
return ptr<basic>(const_cast<basic &>(other));
} else {
// The object is not heap-allocated, so we create a duplicate
// on the heap.
basic *bp = other.duplicate();
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return bp;
}
}
}
basic & ex::construct_from_int(int i)
{
switch (i) { // prefer flyweights over new objects
case -12:
return *const_cast<numeric *>(_num_12_p);
case -11:
return *const_cast<numeric *>(_num_11_p);
case -10:
return *const_cast<numeric *>(_num_10_p);
case -9:
return *const_cast<numeric *>(_num_9_p);
case -8:
return *const_cast<numeric *>(_num_8_p);
case -7:
return *const_cast<numeric *>(_num_7_p);
case -6:
return *const_cast<numeric *>(_num_6_p);
case -5:
return *const_cast<numeric *>(_num_5_p);
case -4:
return *const_cast<numeric *>(_num_4_p);
case -3:
return *const_cast<numeric *>(_num_3_p);
case -2:
return *const_cast<numeric *>(_num_2_p);
case -1:
return *const_cast<numeric *>(_num_1_p);
case 0:
return *const_cast<numeric *>(_num0_p);
case 1:
return *const_cast<numeric *>(_num1_p);
case 2:
return *const_cast<numeric *>(_num2_p);
case 3:
return *const_cast<numeric *>(_num3_p);
case 4:
return *const_cast<numeric *>(_num4_p);
case 5:
return *const_cast<numeric *>(_num5_p);
case 6:
return *const_cast<numeric *>(_num6_p);
case 7:
return *const_cast<numeric *>(_num7_p);
case 8:
return *const_cast<numeric *>(_num8_p);
case 9:
return *const_cast<numeric *>(_num9_p);
case 10:
return *const_cast<numeric *>(_num10_p);
case 11:
return *const_cast<numeric *>(_num11_p);
case 12:
return *const_cast<numeric *>(_num12_p);
default:
basic *bp = new numeric(i);
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return *bp;
}
}
basic & ex::construct_from_uint(unsigned int i)
{
switch (i) { // prefer flyweights over new objects
case 0:
return *const_cast<numeric *>(_num0_p);
case 1:
return *const_cast<numeric *>(_num1_p);
case 2:
return *const_cast<numeric *>(_num2_p);
case 3:
return *const_cast<numeric *>(_num3_p);
case 4:
return *const_cast<numeric *>(_num4_p);
case 5:
return *const_cast<numeric *>(_num5_p);
case 6:
return *const_cast<numeric *>(_num6_p);
case 7:
return *const_cast<numeric *>(_num7_p);
case 8:
return *const_cast<numeric *>(_num8_p);
case 9:
return *const_cast<numeric *>(_num9_p);
case 10:
return *const_cast<numeric *>(_num10_p);
case 11:
return *const_cast<numeric *>(_num11_p);
case 12:
return *const_cast<numeric *>(_num12_p);
default:
basic *bp = new numeric(i);
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return *bp;
}
}
basic & ex::construct_from_long(long i)
{
switch (i) { // prefer flyweights over new objects
case -12:
return *const_cast<numeric *>(_num_12_p);
case -11:
return *const_cast<numeric *>(_num_11_p);
case -10:
return *const_cast<numeric *>(_num_10_p);
case -9:
return *const_cast<numeric *>(_num_9_p);
case -8:
return *const_cast<numeric *>(_num_8_p);
case -7:
return *const_cast<numeric *>(_num_7_p);
case -6:
return *const_cast<numeric *>(_num_6_p);
case -5:
return *const_cast<numeric *>(_num_5_p);
case -4:
return *const_cast<numeric *>(_num_4_p);
case -3:
return *const_cast<numeric *>(_num_3_p);
case -2:
return *const_cast<numeric *>(_num_2_p);
case -1:
return *const_cast<numeric *>(_num_1_p);
case 0:
return *const_cast<numeric *>(_num0_p);
case 1:
return *const_cast<numeric *>(_num1_p);
case 2:
return *const_cast<numeric *>(_num2_p);
case 3:
return *const_cast<numeric *>(_num3_p);
case 4:
return *const_cast<numeric *>(_num4_p);
case 5:
return *const_cast<numeric *>(_num5_p);
case 6:
return *const_cast<numeric *>(_num6_p);
case 7:
return *const_cast<numeric *>(_num7_p);
case 8:
return *const_cast<numeric *>(_num8_p);
case 9:
return *const_cast<numeric *>(_num9_p);
case 10:
return *const_cast<numeric *>(_num10_p);
case 11:
return *const_cast<numeric *>(_num11_p);
case 12:
return *const_cast<numeric *>(_num12_p);
default:
basic *bp = new numeric(i);
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return *bp;
}
}
basic & ex::construct_from_ulong(unsigned long i)
{
switch (i) { // prefer flyweights over new objects
case 0:
return *const_cast<numeric *>(_num0_p);
case 1:
return *const_cast<numeric *>(_num1_p);
case 2:
return *const_cast<numeric *>(_num2_p);
case 3:
return *const_cast<numeric *>(_num3_p);
case 4:
return *const_cast<numeric *>(_num4_p);
case 5:
return *const_cast<numeric *>(_num5_p);
case 6:
return *const_cast<numeric *>(_num6_p);
case 7:
return *const_cast<numeric *>(_num7_p);
case 8:
return *const_cast<numeric *>(_num8_p);
case 9:
return *const_cast<numeric *>(_num9_p);
case 10:
return *const_cast<numeric *>(_num10_p);
case 11:
return *const_cast<numeric *>(_num11_p);
case 12:
return *const_cast<numeric *>(_num12_p);
default:
basic *bp = new numeric(i);
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return *bp;
}
}
basic & ex::construct_from_double(double d)
{
basic *bp = new numeric(d);
bp->setflag(status_flags::dynallocated);
GINAC_ASSERT(bp->get_refcount() == 0);
return *bp;
}
ptr<basic> ex::construct_from_string_and_lst(const std::string &s, const ex &l)
{
set_lexer_string(s);
set_lexer_symbols(l);
ginac_yyrestart(NULL);
if (ginac_yyparse())
throw (std::runtime_error(get_parser_error()));
else
return parsed_ex.bp;
}
//////////
// static member variables
//////////
// none
//////////
// functions which are not member functions
//////////
// none
//////////
// global functions
//////////
// none
} // namespace GiNaC
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