X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fbasic.cpp;h=36ea6419e2217ccb9479db681b9e77a446668e86;hp=5b0b180378bc24df6bd95dbf671ece9f95bc6e56;hb=13d96fc13f6db5b6650d9e6ad688e13051a7685e;hpb=d508ca04e9c2f4ee103c9f21f33a98c87116df13

diff --git a/ginac/basic.cpp b/ginac/basic.cpp
index 5b0b1803..36ea6419 100644
--- a/ginac/basic.cpp
+++ b/ginac/basic.cpp
@@ -33,6 +33,7 @@
 #include "symbol.h"
 #include "lst.h"
 #include "ncmul.h"
+#include "relational.h"
 #include "print.h"
 #include "archive.h"
 #include "utils.h"
@@ -100,12 +101,6 @@ void basic::archive(archive_node &n) const
 	n.add_string("class", class_name());
 }
 
-//////////
-// functions overriding virtual functions from bases classes
-//////////
-
-// none
-
 //////////
 // new virtual functions which can be overridden by derived classes
 //////////
@@ -133,7 +128,7 @@ void basic::print(const print_context & c, unsigned level) const
 		c.s << "[" << class_name() << " object]";
 }
 
-/** Little wrapper arount print to be called within a debugger.
+/** Little wrapper around print to be called within a debugger.
  *  This is needed because you cannot call foo.print(cout) from within the
  *  debugger because it might not know what cout is.  This method can be
  *  invoked with no argument and it will simply print to stdout.
@@ -145,7 +140,7 @@ void basic::dbgprint(void) const
 	std::cerr << std::endl;
 }
 
-/** Little wrapper arount printtree to be called within a debugger.
+/** Little wrapper around printtree to be called within a debugger.
  *
  *  @see basic::dbgprint
  *  @see basic::printtree */
@@ -154,6 +149,12 @@ void basic::dbgprinttree(void) const
 	this->print(print_tree(std::cerr));
 }
 
+/** Return relative operator precedence (for parenthizing output). */
+unsigned basic::precedence(void) const
+{
+	return 70;
+}
+
 /** Create a new copy of this on the heap.  One can think of this as simulating
  *  a virtual copy constructor which is needed for instance by the refcounted
  *  construction of an ex from a basic. */
@@ -206,23 +207,40 @@ ex basic::operator[](int i) const
 	return op(i);
 }
 
-/** Search ocurrences.  An object  'has' an expression if it is the expression
- *  itself or one of the children 'has' it.  As a consequence (according to
- *  the definition of children) given e=x+y+z, e.has(x) is true but e.has(x+y)
- *  is false. */
-bool basic::has(const ex & other) const
+/** Test for occurrence of a pattern.  An object 'has' a pattern if it matches
+ *  the pattern itself or one of the children 'has' it.  As a consequence
+ *  (according to the definition of children) given e=x+y+z, e.has(x) is true
+ *  but e.has(x+y) is false. */
+bool basic::has(const ex & pattern) const
 {
-	GINAC_ASSERT(other.bp!=0);
-	if (is_equal(*other.bp)) return true;
-	if (nops()>0) {
-		for (unsigned i=0; i<nops(); i++)
-			if (op(i).has(other))
-				return true;
-	}
+	GINAC_ASSERT(pattern.bp!=0);
+	lst repl_lst;
+	if (match(*pattern.bp, repl_lst))
+		return true;
+	for (unsigned i=0; i<nops(); i++)
+		if (op(i).has(pattern))
+			return true;
 	
 	return false;
 }
 
+/** Construct new expression by applying the specified function to all
+ *  sub-expressions (one level only, not recursively). */
+ex basic::map(map_function & f) const
+{
+	unsigned num = nops();
+	if (num == 0)
+		return *this;
+
+	basic *copy = duplicate();
+	copy->setflag(status_flags::dynallocated);
+	copy->clearflag(status_flags::hash_calculated | status_flags::expanded);
+	ex e(*copy);
+	for (unsigned i=0; i<num; i++)
+		e.let_op(i) = f(e.op(i));
+	return e.eval();
+}
+
 /** Return degree of highest power in object s. */
 int basic::degree(const ex & s) const
 {
@@ -241,7 +259,7 @@ ex basic::coeff(const ex & s, int n) const
 	return n==0 ? *this : _ex0();
 }
 
-/** Sort expression in terms of powers of some object(s).
+/** Sort expanded expression in terms of powers of some object(s).
  *  @param s object(s) to sort in
  *  @param distributed recursive or distributed form (only used when s is a list) */
 ex basic::collect(const ex & s, bool distributed) const
@@ -250,6 +268,8 @@ ex basic::collect(const ex & s, bool distributed) const
 	if (is_ex_of_type(s, lst)) {
 
 		// List of objects specified
+		if (s.nops() == 0)
+			return *this;
 		if (s.nops() == 1)
 			return collect(s.op(0));
 
@@ -285,7 +305,7 @@ ex basic::collect(const ex & s, bool distributed) const
 				// Increment counters
 				int n = num - 1;
 				while (true) {
-					si[n].cnt++;
+					++si[n].cnt;
 					if (si[n].cnt <= si[n].deg) {
 						// Update coefficients
 						ex c;
@@ -332,11 +352,42 @@ ex basic::eval(int level) const
 	return this->hold();
 }
 
+/** Function object to be applied by basic::evalf(). */
+struct evalf_map_function : public map_function {
+	int level;
+	evalf_map_function(int l) : level(l) {}
+	ex operator()(const ex & e) { return evalf(e, level); }
+};
+
 /** Evaluate object numerically. */
 ex basic::evalf(int level) const
 {
-	// There is nothing to do for basic objects:
-	return *this;
+	if (nops() == 0)
+		return *this;
+	else {
+		if (level == 1)
+			return *this;
+		else if (level == -max_recursion_level)
+			throw(std::runtime_error("max recursion level reached"));
+		else {
+			evalf_map_function map_evalf(level - 1);
+			return map(map_evalf);
+		}
+	}
+}
+
+/** Function object to be applied by basic::evalm(). */
+struct evalm_map_function : public map_function {
+	ex operator()(const ex & e) { return evalm(e); }
+} map_evalm;
+
+/** Evaluate sums, products and integer powers of matrices. */
+ex basic::evalm(void) const
+{
+	if (nops() == 0)
+		return *this;
+	else
+		return map(map_evalm);
 }
 
 /** Perform automatic symbolic evaluations on indexed expression that
@@ -392,15 +443,85 @@ bool basic::contract_with(exvector::iterator self, exvector::iterator other, exv
 	return false;
 }
 
+/** Check whether the expression matches a given pattern. For every wildcard
+ *  object in the pattern, an expression of the form "wildcard == matching_expression"
+ *  is added to repl_lst. */
+bool basic::match(const ex & pattern, lst & repl_lst) const
+{
+/*
+	Sweet sweet shapes, sweet sweet shapes,
+	That's the key thing, right right.
+	Feed feed face, feed feed shapes,
+	But who is the king tonight?
+	Who is the king tonight?
+	Pattern is the thing, the key thing-a-ling,
+	But who is the king of Pattern?
+	But who is the king, the king thing-a-ling,
+	Who is the king of Pattern?
+	Bog is the king, the king thing-a-ling,
+	Bog is the king of Pattern.
+	Ba bu-bu-bu-bu bu-bu-bu-bu-bu-bu bu-bu
+	Bog is the king of Pattern.
+*/
+
+	if (is_ex_exactly_of_type(pattern, wildcard)) {
+
+		// Wildcard matches anything, but check whether we already have found
+		// a match for that wildcard first (if so, it the earlier match must
+		// be the same expression)
+		for (unsigned i=0; i<repl_lst.nops(); i++) {
+			if (repl_lst.op(i).op(0).is_equal(pattern))
+				return is_equal(*repl_lst.op(i).op(1).bp);
+		}
+		repl_lst.append(pattern == *this);
+		return true;
+
+	} else {
+
+		// Expression must be of the same type as the pattern
+		if (tinfo() != pattern.bp->tinfo())
+			return false;
+
+		// Number of subexpressions must match
+		if (nops() != pattern.nops())
+			return false;
+
+		// No subexpressions? Then just compare the objects (there can't be
+		// wildcards in the pattern)
+		if (nops() == 0)
+			return is_equal_same_type(*pattern.bp);
+
+		// Check whether attributes that are not subexpressions match
+		if (!match_same_type(*pattern.bp))
+			return false;
+
+		// Otherwise the subexpressions must match one-to-one
+		for (unsigned i=0; i<nops(); i++)
+			if (!op(i).match(pattern.op(i), repl_lst))
+				return false;
+
+		// Looks similar enough, match found
+		return true;
+	}
+}
+
 /** Substitute a set of objects by arbitrary expressions. The ex returned
  *  will already be evaluated. */
-ex basic::subs(const lst & ls, const lst & lr) const
+ex basic::subs(const lst & ls, const lst & lr, bool no_pattern) const
 {
 	GINAC_ASSERT(ls.nops() == lr.nops());
 
-	for (unsigned i=0; i<ls.nops(); i++) {
-		if (is_equal(*ls.op(i).bp))
-			return lr.op(i);
+	if (no_pattern) {
+		for (unsigned i=0; i<ls.nops(); i++) {
+			if (is_equal(*ls.op(i).bp))
+				return lr.op(i);
+		}
+	} else {
+		for (unsigned i=0; i<ls.nops(); i++) {
+			lst repl_lst;
+			if (match(*ls.op(i).bp, repl_lst))
+				return lr.op(i).bp->subs(repl_lst, true); // avoid infinite recursion when re-substituting the wildcards
+		}
 	}
 
 	return *this;
@@ -445,13 +566,25 @@ ex basic::simplify_ncmul(const exvector & v) const
 
 // protected
 
-/** Default implementation of ex::diff(). It simply throws an error message.
+/** Function object to be applied by basic::derivative(). */
+struct derivative_map_function : public map_function {
+	const symbol &s;
+	derivative_map_function(const symbol &sym) : s(sym) {}
+	ex operator()(const ex & e) { return diff(e, s); }
+};
+
+/** Default implementation of ex::diff(). It maps the operation on the
+ *  operands (or returns 0 when the object has no operands).
  *
- *  @exception logic_error (differentiation not supported by this type)
  *  @see ex::diff */
 ex basic::derivative(const symbol & s) const
 {
-	throw(std::logic_error("differentiation not supported by this type"));
+	if (nops() == 0)
+		return _ex0();
+	else {
+		derivative_map_function map_derivative(s);
+		return map(map_derivative);
+	}
 }
 
 /** Returns order relation between two objects of same type.  This needs to be
@@ -471,7 +604,24 @@ int basic::compare_same_type(const basic & other) const
  *  than an order relation and then it can be overridden. */
 bool basic::is_equal_same_type(const basic & other) const
 {
-	return this->compare_same_type(other)==0;
+	return compare_same_type(other)==0;
+}
+
+/** Returns true if the attributes of two objects are similar enough for
+ *  a match. This function must not match subexpressions (this is already
+ *  done by basic::match()). Only attributes not accessible by op() should
+ *  be compared. This is also the reason why this function doesn't take the
+ *  wildcard replacement list from match() as an argument: only subexpressions
+ *  are subject to wildcard matches. Also, this function only needs to be
+ *  implemented for container classes because is_equal_same_type() is
+ *  automatically used instead of match_same_type() if nops() == 0.
+ *
+ *  @see basic::match */
+bool basic::match_same_type(const basic & other) const
+{
+	// The default is to only consider subexpressions, but not any other
+	// attributes
+	return true;
 }
 
 unsigned basic::return_type(void) const
@@ -510,11 +660,23 @@ unsigned basic::calchash(void) const
 	return v;
 }
 
+/** Function object to be applied by basic::expand(). */
+struct expand_map_function : public map_function {
+	unsigned options;
+	expand_map_function(unsigned o) : options(o) {}
+	ex operator()(const ex & e) { return expand(e, options); }
+};
+
 /** Expand expression, i.e. multiply it out and return the result as a new
  *  expression. */
 ex basic::expand(unsigned options) const
 {
-	return this->setflag(status_flags::expanded);
+	if (nops() == 0)
+		return (options == 0) ? setflag(status_flags::expanded) : *this;
+	else {
+		expand_map_function map_expand(options);
+		return map(map_expand).bp->setflag(options == 0 ? status_flags::expanded : 0);
+	}
 }
 
 
@@ -529,10 +691,10 @@ ex basic::expand(unsigned options) const
  *  replacement arguments: 1) a relational like object==ex and 2) a list of
  *  relationals lst(object1==ex1,object2==ex2,...), which is converted to
  *  subs(lst(object1,object2,...),lst(ex1,ex2,...)). */
-ex basic::subs(const ex & e) const
+ex basic::subs(const ex & e, bool no_pattern) const
 {
 	if (e.info(info_flags::relation_equal)) {
-		return subs(lst(e));
+		return subs(lst(e), no_pattern);
 	}
 	if (!e.info(info_flags::list)) {
 		throw(std::invalid_argument("basic::subs(ex): argument must be a list"));
@@ -547,7 +709,7 @@ ex basic::subs(const ex & e) const
 		ls.append(r.op(0));
 		lr.append(r.op(1));
 	}
-	return subs(ls, lr);
+	return subs(ls, lr, no_pattern);
 }
 
 /** Compare objects to establish canonical ordering.
@@ -614,7 +776,7 @@ bool basic::is_equal(const basic & other) const
 	
 	GINAC_ASSERT(typeid(*this)==typeid(other));
 	
-	return this->is_equal_same_type(other);
+	return is_equal_same_type(other);
 }
 
 // protected
@@ -624,7 +786,7 @@ bool basic::is_equal(const basic & other) const
  *  @see basic::eval */
 const basic & basic::hold(void) const
 {
-	return this->setflag(status_flags::evaluated);
+	return setflag(status_flags::evaluated);
 }
 
 /** Ensure the object may be modified without hurting others, throws if this
@@ -633,16 +795,9 @@ void basic::ensure_if_modifiable(void) const
 {
 	if (this->refcount>1)
 		throw(std::runtime_error("cannot modify multiply referenced object"));
+	clearflag(status_flags::hash_calculated);
 }
 
-//////////
-// static member variables
-//////////
-
-// protected
-
-unsigned basic::precedence = 70;
-
 //////////
 // global variables
 //////////