| 0,0 → 1,78 |
|---|
| |
| #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 |
| |