kolibrios/contrib/media/updf/include/substitute.h
right-hearted 4f7ee97ec9 uPDF with buttons
git-svn-id: svn://kolibrios.org@4680 a494cfbc-eb01-0410-851d-a64ba20cac60
2014-03-22 21:00:40 +00:00

79 lines
2.1 KiB
C++

#ifndef __substitute_h__
#define __substitute_h__
#include "yacasbase.h"
#include "lispobject.h"
#include "lispenvironment.h"
/** Behaviour for substituting sub-expressions.
*/
class SubstBehaviourBase : public YacasBase
{
public:
virtual ~SubstBehaviourBase();
virtual LispBoolean Matches(LispPtr& aResult, LispPtr& aElement) = 0;
};
/** main routine that can perform substituting of expressions
*/
void InternalSubstitute(LispPtr& aTarget, LispPtr& aSource,
SubstBehaviourBase& aBehaviour);
/** Substing one expression for another. The simplest form
* of substitution
*/
class SubstBehaviour : public SubstBehaviourBase
{
public:
SubstBehaviour(LispEnvironment& aEnvironment,LispPtr& aToMatch,
LispPtr& aToReplaceWith);
virtual LispBoolean Matches(LispPtr& aResult, LispPtr& aElement);
private:
LispEnvironment& iEnvironment;
LispPtr& iToMatch;
LispPtr& iToReplaceWith;
};
/** subst behaviour for changing the local variables to have unique
* names.
*/
class LocalSymbolBehaviour : public SubstBehaviourBase
{
public:
LocalSymbolBehaviour(LispEnvironment& aEnvironment,
LispString ** aOriginalNames,
LispString ** aNewNames, LispInt aNrNames);
virtual LispBoolean Matches(LispPtr& aResult, LispPtr& aElement);
private:
LispEnvironment& iEnvironment;
LispString ** iOriginalNames;
LispString ** iNewNames;
LispInt iNrNames;
};
/** subst behaviour for backquote mechanism as in LISP.
* When typing `(...) all occurrences of @a will be
* replaced with:
* 1) a evaluated if a is an atom
* 2) function call with function name replaced by evaluated
* head of function if a is a function. For instance, if
* a is f(x) and f is g, then f(x) gets replaced by g(x)
*/
class BackQuoteBehaviour : public SubstBehaviourBase
{
public:
BackQuoteBehaviour(LispEnvironment& aEnvironment)
: iEnvironment(aEnvironment) {};
virtual LispBoolean Matches(LispPtr& aResult, LispPtr& aElement);
LispEnvironment& iEnvironment;
};
#endif