forked from KolibriOS/kolibrios
79 lines
2.1 KiB
C
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
|
||
|
|