+ * @struct _LttvFilter
+ * @brief The filter
+ *
+ * Contains a binary tree of filtering options along
+ * with the expression itself.
+ */
+struct _LttvFilter {
+ char *expression; /**< filtering expression string */
+ LttvFilterTree *head; /**< tree associated to expression */
+};
+
+/*
+ * Simple Expression
+ */
+LttvSimpleExpression* lttv_simple_expression_new();
+
+gboolean lttv_simple_expression_assign_field(GPtrArray* fp, LttvSimpleExpression* se);
+
+gboolean lttv_simple_expression_assign_operator(LttvSimpleExpression* se, LttvExpressionOp op);
+
+gboolean lttv_simple_expression_assign_value(LttvSimpleExpression* se, char* value);
+
+void lttv_simple_expression_destroy(LttvSimpleExpression* se);
+
+
+/*
+ * Logical operators functions
+ */
+
+gboolean lttv_apply_op_eq_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_string(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_quark(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_eq_ltttime(const gpointer v1, LttvFieldValue v2);
+
+gboolean lttv_apply_op_ne_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_string(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_quark(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ne_ltttime(const gpointer v1, LttvFieldValue v2);
+
+gboolean lttv_apply_op_lt_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_lt_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_lt_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_lt_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_lt_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_lt_ltttime(const gpointer v1, LttvFieldValue v2);
+
+gboolean lttv_apply_op_le_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_le_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_le_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_le_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_le_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_le_ltttime(const gpointer v1, LttvFieldValue v2);
+
+gboolean lttv_apply_op_gt_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_gt_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_gt_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_gt_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_gt_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_gt_ltttime(const gpointer v1, LttvFieldValue v2);
+
+gboolean lttv_apply_op_ge_uint(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ge_uint64(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ge_uint32(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ge_uint16(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ge_double(const gpointer v1, LttvFieldValue v2);
+gboolean lttv_apply_op_ge_ltttime(const gpointer v1, LttvFieldValue v2);
+
+/*
+ * Cloning