X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fex.cpp;h=40a7de2fefe1a51cdabd570bdec8ff33297e7fd4;hp=02d20e8894f1308e14850fced01d4cd43a8f0c68;hb=e8c9b4a51a1c8f1230b023b0af6a708881ef23d3;hpb=04f0c93e24cdb50f23cb3a6c0ecbeaac23b13ac0 diff --git a/ginac/ex.cpp b/ginac/ex.cpp index 02d20e88..40a7de2f 100644 --- a/ginac/ex.cpp +++ b/ginac/ex.cpp @@ -3,7 +3,7 @@ * Implementation of GiNaC's light-weight expression handles. */ /* - * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2003 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 @@ -29,53 +29,25 @@ #include "ncmul.h" #include "numeric.h" #include "power.h" +#include "lst.h" #include "relational.h" -#include "indexed.h" #include "input_lexer.h" -#include "debugmsg.h" #include "utils.h" namespace GiNaC { ////////// -// other ctors +// other constructors ////////// // none (all inlined) -////////// -// functions overriding virtual functions from bases classes -////////// - -// none - -////////// -// new virtual functions which can be overridden by derived classes -////////// - -// none - ////////// // non-virtual functions in this class ////////// // public - -/** Efficiently swap the contents of two expressions. */ -void ex::swap(ex & other) -{ - debugmsg("ex swap",LOGLEVEL_MEMBER_FUNCTION); - - GINAC_ASSERT(bp!=0); - GINAC_ASSERT(bp->flags & status_flags::dynallocated); - GINAC_ASSERT(other.bp!=0); - GINAC_ASSERT(other.bp->flags & status_flags::dynallocated); - basic * tmpbp = bp; - bp = other.bp; - other.bp = tmpbp; -} - /** 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 @@ -83,39 +55,24 @@ void ex::swap(ex & other) * @see print_context */ void ex::print(const print_context & c, unsigned level) const { - debugmsg("ex print", LOGLEVEL_PRINT); - GINAC_ASSERT(bp!=0); bp->print(c, level); } -/** Print expression to stream in a tree-like format suitable for debugging. */ -void ex::printtree(std::ostream & os) const -{ - debugmsg("ex printtree", LOGLEVEL_PRINT); - GINAC_ASSERT(bp!=0); - bp->print(print_tree(os)); -} - /** Little wrapper arount print to be called within a debugger. */ -void ex::dbgprint(void) const +void ex::dbgprint() const { - debugmsg("ex dbgprint", LOGLEVEL_PRINT); - GINAC_ASSERT(bp!=0); bp->dbgprint(); } /** Little wrapper arount printtree to be called within a debugger. */ -void ex::dbgprinttree(void) const +void ex::dbgprinttree() const { - debugmsg("ex dbgprinttree", LOGLEVEL_PRINT); - GINAC_ASSERT(bp!=0); bp->dbgprinttree(); } 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); @@ -128,75 +85,150 @@ ex ex::expand(unsigned options) const * @return partial derivative as a new expression */ ex ex::diff(const symbol & s, unsigned nth) const { - GINAC_ASSERT(bp!=0); - if (!nth) return *this; else return bp->diff(s, nth); } -/** Simplify/canonicalize expression containing indexed objects. This - * performs contraction of dummy indices where possible and checks whether - * the free indices in sums are consistent. - * - * @return simplified expression */ -ex ex::simplify_indexed(void) const +/** Check whether expression matches a specified pattern. */ +bool ex::match(const ex & pattern) const { - return GiNaC::simplify_indexed(*this); + lst repl_lst; + return bp->match(pattern, repl_lst); } -/** Simplify/canonicalize expression containing indexed objects. This - * performs contraction of dummy indices where possible, checks whether - * the free indices in sums are consistent, and automatically replaces - * scalar products by known values if desired. - * - * @param sp Scalar products to be replaced automatically - * @return simplified expression */ -ex ex::simplify_indexed(const scalar_products & sp) const +/** 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 { - return GiNaC::simplify_indexed(*this, sp); + if (match(pattern)) { + found.append(*this); + found.sort(); + found.unique(); + return true; + } + bool any_found = false; + for (size_t i=0; i(*its) || is_exactly_a(*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); } -ex ex::operator[](int i) const +/** 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 { - debugmsg("ex operator[int]",LOGLEVEL_OPERATOR); - GINAC_ASSERT(bp!=0); - return (*bp)[i]; + if (e.info(info_flags::relation_equal)) { + exmap m; + const ex & s = e.lhs(); + m.insert(std::make_pair(s, e.rhs())); + if (is_exactly_a(s) || is_exactly_a(s)) + options |= subs_options::pattern_is_product; + return bp->subs(m, options); + } else if (!e.info(info_flags::list)) + throw(std::invalid_argument("basic::subs(ex): argument must be a list")); + + // Convert the list to a map + exmap m; + GINAC_ASSERT(is_a(e)); + for (lst::const_iterator it = ex_to(e).begin(); it != ex_to(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.lhs(); + m.insert(std::make_pair(s, r.rhs())); + + // Search for products and powers in the expressions to be substituted + // (for an optimization in expairseq::subs()) + if (is_exactly_a(s) || is_exactly_a(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); +} + +/** 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(int i) +ex & ex::let_op(size_t i) { - debugmsg("ex let_op()",LOGLEVEL_MEMBER_FUNCTION); makewriteable(); - GINAC_ASSERT(bp!=0); 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(void) const +ex ex::lhs() const { - debugmsg("ex lhs()",LOGLEVEL_MEMBER_FUNCTION); - if (!is_ex_of_type(*this,relational)) + if (!is_a(*this)) throw std::runtime_error("ex::lhs(): not a relation"); - return (*static_cast(bp)).lhs(); + return bp->op(0); } /** Right hand side of relational expression. */ -ex ex::rhs(void) const +ex ex::rhs() const { - debugmsg("ex rhs()",LOGLEVEL_MEMBER_FUNCTION); - if (!is_ex_of_type(*this,relational)) + if (!is_a(*this)) throw std::runtime_error("ex::rhs(): not a relation"); - return (*static_cast(bp)).rhs(); + return bp->op(1); } // private @@ -205,182 +237,298 @@ ex ex::rhs(void) const * unlinking the object and creating an unshared copy of it. */ void ex::makewriteable() { - debugmsg("ex makewriteable",LOGLEVEL_MEMBER_FUNCTION); - GINAC_ASSERT(bp!=0); GINAC_ASSERT(bp->flags & status_flags::dynallocated); - if (bp->refcount > 1) { - basic * bp2 = bp->duplicate(); - ++bp2->refcount; - bp2->setflag(status_flags::dynallocated); - --bp->refcount; - bp = bp2; - } - GINAC_ASSERT(bp->refcount==1); + bp.makewritable(); + GINAC_ASSERT(bp->get_refcount() == 1); } -/** Ctor from basic implementation. +/** Share equal objects between expressions. + * @see ex::compare(const basic &) */ +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 &) */ -void ex::construct_from_basic(const basic & other) +ptr ex::construct_from_basic(const basic & other) { - if ((other.flags & status_flags::evaluated)==0) { - // cf. copy ctor - const ex & tmpex = other.eval(1); // evaluate only one (top) level - bp = tmpex.bp; - GINAC_ASSERT(bp!=0); - GINAC_ASSERT(bp->flags & status_flags::dynallocated); - ++bp->refcount; - if ((other.flags & status_flags::dynallocated)&&(other.refcount==0)) - delete &const_cast(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) { - // ok, it is already on the heap, so just copy bp: - bp = &const_cast(other); + + // The object is already heap-allocated, so we can just make + // another reference to it. + return ptr(const_cast(other)); + } else { - // create a duplicate on the heap: - bp = other.duplicate(); + + // 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; } - GINAC_ASSERT(bp!=0); - ++bp->refcount; } - GINAC_ASSERT(bp!=0); - GINAC_ASSERT(bp->flags & status_flags::dynallocated); } -void ex::construct_from_int(int i) +basic & ex::construct_from_int(int i) { - switch (i) { // some tiny efficiency-hack + switch (i) { // prefer flyweights over new objects + case -12: + return const_cast(_num_12); + case -11: + return const_cast(_num_11); + case -10: + return const_cast(_num_10); + case -9: + return const_cast(_num_9); + case -8: + return const_cast(_num_8); + case -7: + return const_cast(_num_7); + case -6: + return const_cast(_num_6); + case -5: + return const_cast(_num_5); + case -4: + return const_cast(_num_4); + case -3: + return const_cast(_num_3); case -2: - bp = _ex_2().bp; - ++bp->refcount; - break; + return const_cast(_num_2); case -1: - bp = _ex_1().bp; - ++bp->refcount; - break; + return const_cast(_num_1); case 0: - bp = _ex0().bp; - ++bp->refcount; - break; + return const_cast(_num0); case 1: - bp = _ex1().bp; - ++bp->refcount; - break; + return const_cast(_num1); case 2: - bp = _ex2().bp; - ++bp->refcount; - break; + return const_cast(_num2); + case 3: + return const_cast(_num3); + case 4: + return const_cast(_num4); + case 5: + return const_cast(_num5); + case 6: + return const_cast(_num6); + case 7: + return const_cast(_num7); + case 8: + return const_cast(_num8); + case 9: + return const_cast(_num9); + case 10: + return const_cast(_num10); + case 11: + return const_cast(_num11); + case 12: + return const_cast(_num12); default: - bp = new numeric(i); + basic *bp = new numeric(i); bp->setflag(status_flags::dynallocated); - ++bp->refcount; - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - GINAC_ASSERT(bp->refcount==1); + GINAC_ASSERT(bp->get_refcount() == 0); + return *bp; } } -void ex::construct_from_uint(unsigned int i) +basic & ex::construct_from_uint(unsigned int i) { - switch (i) { // some tiny efficiency-hack + switch (i) { // prefer flyweights over new objects case 0: - bp = _ex0().bp; - ++bp->refcount; - break; + return const_cast(_num0); case 1: - bp = _ex1().bp; - ++bp->refcount; - break; + return const_cast(_num1); case 2: - bp = _ex2().bp; - ++bp->refcount; - break; + return const_cast(_num2); + case 3: + return const_cast(_num3); + case 4: + return const_cast(_num4); + case 5: + return const_cast(_num5); + case 6: + return const_cast(_num6); + case 7: + return const_cast(_num7); + case 8: + return const_cast(_num8); + case 9: + return const_cast(_num9); + case 10: + return const_cast(_num10); + case 11: + return const_cast(_num11); + case 12: + return const_cast(_num12); default: - bp = new numeric(i); + basic *bp = new numeric(i); bp->setflag(status_flags::dynallocated); - ++bp->refcount; - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - GINAC_ASSERT(bp->refcount==1); + GINAC_ASSERT(bp->get_refcount() == 0); + return *bp; } } -void ex::construct_from_long(long i) +basic & ex::construct_from_long(long i) { - switch (i) { // some tiny efficiency-hack + switch (i) { // prefer flyweights over new objects + case -12: + return const_cast(_num_12); + case -11: + return const_cast(_num_11); + case -10: + return const_cast(_num_10); + case -9: + return const_cast(_num_9); + case -8: + return const_cast(_num_8); + case -7: + return const_cast(_num_7); + case -6: + return const_cast(_num_6); + case -5: + return const_cast(_num_5); + case -4: + return const_cast(_num_4); + case -3: + return const_cast(_num_3); case -2: - bp = _ex_2().bp; - ++bp->refcount; - break; + return const_cast(_num_2); case -1: - bp = _ex_1().bp; - ++bp->refcount; - break; + return const_cast(_num_1); case 0: - bp = _ex0().bp; - ++bp->refcount; - break; + return const_cast(_num0); case 1: - bp = _ex1().bp; - ++bp->refcount; - break; + return const_cast(_num1); case 2: - bp = _ex2().bp; - ++bp->refcount; - break; + return const_cast(_num2); + case 3: + return const_cast(_num3); + case 4: + return const_cast(_num4); + case 5: + return const_cast(_num5); + case 6: + return const_cast(_num6); + case 7: + return const_cast(_num7); + case 8: + return const_cast(_num8); + case 9: + return const_cast(_num9); + case 10: + return const_cast(_num10); + case 11: + return const_cast(_num11); + case 12: + return const_cast(_num12); default: - bp = new numeric(i); + basic *bp = new numeric(i); bp->setflag(status_flags::dynallocated); - ++bp->refcount; - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - GINAC_ASSERT(bp->refcount==1); + GINAC_ASSERT(bp->get_refcount() == 0); + return *bp; } } -void ex::construct_from_ulong(unsigned long i) +basic & ex::construct_from_ulong(unsigned long i) { - switch (i) { // some tiny efficiency-hack + switch (i) { // prefer flyweights over new objects case 0: - bp = _ex0().bp; - ++bp->refcount; - break; + return const_cast(_num0); case 1: - bp = _ex1().bp; - ++bp->refcount; - break; + return const_cast(_num1); case 2: - bp = _ex2().bp; - ++bp->refcount; - break; + return const_cast(_num2); + case 3: + return const_cast(_num3); + case 4: + return const_cast(_num4); + case 5: + return const_cast(_num5); + case 6: + return const_cast(_num6); + case 7: + return const_cast(_num7); + case 8: + return const_cast(_num8); + case 9: + return const_cast(_num9); + case 10: + return const_cast(_num10); + case 11: + return const_cast(_num11); + case 12: + return const_cast(_num12); default: - bp = new numeric(i); + basic *bp = new numeric(i); bp->setflag(status_flags::dynallocated); - ++bp->refcount; - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - GINAC_ASSERT(bp->refcount==1); + GINAC_ASSERT(bp->get_refcount() == 0); + return *bp; } } -void ex::construct_from_double(double d) +basic & ex::construct_from_double(double d) { - bp = new numeric(d); + basic *bp = new numeric(d); bp->setflag(status_flags::dynallocated); - ++bp->refcount; - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - GINAC_ASSERT(bp->refcount==1); + GINAC_ASSERT(bp->get_refcount() == 0); + return *bp; } -void ex::construct_from_string_and_lst(const std::string &s, const ex &l) +ptr 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 { - bp = parsed_ex.bp; - GINAC_ASSERT(bp!=0); - GINAC_ASSERT((bp->flags) & status_flags::dynallocated); - ++bp->refcount; - } + else + return parsed_ex.bp; } //////////