Files
Finite-State-Machine/include/fsm.h
2025-01-13 23:52:04 +05:30

133 lines
2.9 KiB
C

#ifndef __FSM__
#define __FSM__
/***Constants***/
#define MAX_INP_BUFFER_LEN 128
#define MAX_TRANSITION_TABLE_SIZE 128
#define MAX_STATE_NAME_SIZE 32
#define MAX_FSM_NAME_SIZE 32
#define MAX_TRANSITION_KEY_SIZE 64
/***Data structures and custom datatypes***/
typedef struct fsm_ fsm_t;
typedef struct state_ state_t;
/*Custom-defined datatype
* to define boolean value
* for FSM*/
typedef enum{
FSM_FALSE,
FSM_TRUE
}fsm_bool_t;
/*This data structure act similar
* to the behaviour of transition
* function.*/
typedef struct tt_entry_{
/* The input symbol */
char transition_key[MAX_TRANSITION_KEY_SIZE];
/* Size of the input symbol */
unsigned int transition_key_size;
/* Next state: The state which is the output
* of transition function, i.e.
* f(state_i, input_symbol) = (state_i+1)*/
state_t *next_state;
}tt_entry_t;
typedef struct tt_{
tt_entry_t tt_entry[MAX_TRANSITION_TABLE_SIZE];
}tt_t;
struct state_{
/*Name/identifier of the state.
* This should be unique*/
char state_name[MAX_STATE_NAME_SIZE];
/*Transition table of the state*/
tt_t state_trans_table;
/*Boolean value to distinguish b/w
* accept/final state or vice-versa*/
fsm_bool_t is_final;
};
struct fsm_{
/*Initial state of FSM to start with*/
state_t *initial_state;
/*Name of FSM*/
char fsm_name[MAX_FSM_NAME_SIZE];
/*Input data fed by application to parse
* by FSM library*/
char input_buffer[MAX_INP_BUFFER_LEN];
/*Size of input buffer*/
unsigned int input_buffer_size;
/*Pointer which point to the current input
* from input buffer*/
unsigned int input_buffer_cursor;
};
/***Function Prototypes***/
fsm_t*
create_new_fsm(const char *fsm_name);
state_t*
create_new_state(char *state_name,
fsm_bool_t is_final);
void
set_fsm_initial_state(fsm_t *fsm, state_t *state);
tt_entry_t*
create_and_insert_new_tt_entry(tt_t *trans_table,
char *transition_key,
unsigned int sizeof_key,
state_t* next_state);
tt_entry_t*
get_next_empty_tt_entry(tt_t *trans_table);
/**static(hidden) functions***/
static inline fsm_bool_t
is_tt_entry_empty(tt_entry_t *tt_entry){
if(!tt_entry->next_state)
return FSM_TRUE;
return FSM_FALSE;
}
/***Iterators' Macro***/
#define FSM_ITERATE_TRANS_TABLE_BEGIN(tr_table_ptr, tt_entry_ptr) \
do{ \
unsigned int index = 0; \
for( ; index < MAX_TRANSITION_TABLE_SIZE ; index++ ){ \
tt_entry_ptr = &(tr_table_ptr->tt_entry[index]);
#define FSM_ITERATE_TRANS_TABLE_END(tr_table_ptr, tt_entry_ptr) \
} \
}while(0);
#endif