#include <stdbool.h>

enum pattern_form {
    pattern_var,
    pattern_int_lit,
    pattern_bool_lit,
    pattern_string_lit,
    pattern_list_lit,
    pattern_tuple_lit,
    pattern_constructor,
};

struct pattern;

struct pattern_list {
    struct pattern *elem;
    struct pattern_list *next;
};

struct pattern_list_builder {
    struct pattern_list *head;
    struct pattern_list *last;
};

void pattern_list_append(struct pattern_list_builder *b, struct pattern *p);
void free_pattern_list(struct pattern_list *l);

struct constructor_pattern {
    char *name;
    struct pattern_list *args;
};

struct pattern {
    enum pattern_form form;
    union {
        /* Useful for vars, ints and strings */
        char *lexeme;
        bool b;
        struct pattern_list *list;
        struct pattern_list *tuple;
        struct constructor_pattern ctor;
    };
};

struct pattern *make_var_pattern(char *name);
struct pattern *make_int_pattern(char *lexeme);
struct pattern *make_bool_pattern(bool b);
struct pattern *make_string_pattern(char *lexeme);
struct pattern *make_list_pattern(struct pattern_list *l);
struct pattern *make_tuple_pattern(struct pattern_list *l);
struct pattern *make_constructor_pattern(char *name, struct pattern_list *args);

void free_pattern(struct pattern *p);