ParseTree.h

// these are the different types of operators that can appear
// in a CNF expression
#define LESS_THAN 1
#define GREATER_THAN 2
#define EQUALS 3

// these are the types of operands that can appear in a CNF expression
#define DOUBLE 1
#define INT 2
#define STRING 3
#define NAME 4

struct Operand {

	// this tells us the type of the operand: FLOAT, INT, STRING...
	int code;

	// this is the actual operand
	char *value;
};

struct ComparisonOp {

	// this corresponds to one of the codes describing what type
	// of literal value we have in this nodes: LESS_THAN, EQUALS...
	int code;

	// these are the operands on the left and on the right
	struct Operand *left;
	struct Operand *right;	
};

struct OrList {

	// this is the comparison to the left of the OR
	struct ComparisonOp *left;

	// this is the OrList to the right of the OR; again,
	// this might be NULL if the right is a simple comparison
	struct OrList *rightOr;
};

struct AndList {

	// this is the disjunction to the left of the AND
	struct OrList *left;

	// this is the AndList to the right of the AND
	// note that this can be NULL if the right is a disjunction
	struct AndList *rightAnd;

};