43795ab11a
(An improved version in conjunction with ktcc can generate executable files.) git-svn-id: svn://kolibrios.org@8733 a494cfbc-eb01-0410-851d-a64ba20cac60
177 lines
3.9 KiB
C
177 lines
3.9 KiB
C
/*
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* Tiny BASIC
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* Expression Handling Header
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*
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* Released as Public Domain by Damian Gareth Walker 2019
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* Created: 16-Aug-2019
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*/
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#ifndef __EXPRESSION_H__
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#define __EXPRESSION_H__
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/* Forward Declarations */
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typedef struct expression_node ExpressionNode;
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typedef struct right_hand_term RightHandTerm;
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typedef struct term_node TermNode;
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typedef struct right_hand_factor RightHandFactor;
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/*
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* Data Definitions - Factors
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*/
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/* The different classes of factor */
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typedef enum {
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FACTOR_NONE, /* class as yet undetermined */
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FACTOR_VARIABLE, /* a variable */
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FACTOR_VALUE, /* an integer value */
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FACTOR_EXPRESSION /* a bracketed expression */
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} FactorClass;
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/* The signs */
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typedef enum {
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SIGN_POSITIVE,
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SIGN_NEGATIVE
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} SignClass;
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/* A factor */
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typedef struct {
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FactorClass class; /* what kind of factor is this? */
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SignClass sign; /* which sign, positive or negative? */
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union {
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int variable;
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int value;
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ExpressionNode *expression;
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} data;
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} FactorNode;
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/* The term operators */
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typedef enum {
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TERM_OPERATOR_NONE, /* single-factor term */
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TERM_OPERATOR_MULTIPLY, /* multiply */
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TERM_OPERATOR_DIVIDE /* divide */
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} TermOperator;
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/* the operator and right-hand part of a term */
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typedef struct right_hand_factor {
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TermOperator op; /* the operator to apply: muliply or divide */
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FactorNode *factor; /* the factor to multiply or divide by */
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RightHandFactor *next; /* the next part of the term, if any */
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} RightHandFactor;
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/* A term */
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typedef struct term_node {
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FactorNode *factor; /* the first factor of an expression */
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RightHandFactor *next; /* the right side term, if any */
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} TermNode;
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/* Expression Operator */
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typedef enum {
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EXPRESSION_OPERATOR_NONE, /* single-term expression */
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EXPRESSION_OPERATOR_PLUS, /* addition */
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EXPRESSION_OPERATOR_MINUS /* substraction */
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} ExpressionOperator;
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/* the operator and right-hand part of an expression */
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typedef struct right_hand_term {
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ExpressionOperator op; /* the operator to apply: plus or minus */
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TermNode *term; /* the term to add or subtract */
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RightHandTerm *next; /* next part of the expression, if any */
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} RightHandTerm;
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/* An expression */
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typedef struct expression_node {
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TermNode *term; /* The first term of an expression */
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RightHandTerm *next; /* the right side expression, if any */
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} ExpressionNode;
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/*
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* Function Declarations
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*/
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/*
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* Constructor for a factor
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* returns:
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* FactorNode* the new factor
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*/
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FactorNode *factor_create (void);
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/*
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* Destructor for a factor
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* params:
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* FactorNode* factor the doomed factor
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*/
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void factor_destroy (FactorNode *factor);
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/*
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* Constructor for a right-hand factor of a term
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* returns:
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* RightHandFactor* the new RH factor of a term
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*/
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RightHandFactor *rhfactor_create (void);
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/*
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* Recursive destructor for a right-hand factor of a term
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* params:
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* RightHandFactor* rhterm the doomed RH factor of a term
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*/
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void rhfactor_destroy (RightHandFactor *rhterm);
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/*
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* Constructor for a term
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* returns:
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* TermNode* the new term
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*/
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TermNode *term_create (void);
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/*
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* Destructor for a term
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* params:
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* TermNode* term the doomed term
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*/
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void term_destroy (TermNode *term);
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/*
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* Constructor for a right-hand expression
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* returns:
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* RightHandTerm* the RH term of an expression
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*/
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RightHandTerm *rhterm_create (void);
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/*
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* Recursive destructor for a right-hand term of an expression
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* params:
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* RightHandTerm* rhexpression the doomed RH expression
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*/
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void rhterm_destroy (RightHandTerm *rhterm);
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/*
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* Constructor for an expression
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* returns:
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* ExpressionNode* the new expression
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*/
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ExpressionNode *expression_create (void);
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/*
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* Destructor for a factor
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* params:
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* FactorNode* factor the doomed factor
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*/
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void factor_destroy (FactorNode *factor);
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/*
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* Destructor for a expression
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* params:
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* ExpressionNode* expression the doomed expression
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*/
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void expression_destroy (ExpressionNode *expression);
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#endif
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