#ifndef LEXER_H
#define LEXER_H

#ifndef LEXER_IDEN_CAP
#define LEXER_IDEN_CAP 512
#endif

typedef struct lexer *lexer_t;

struct token {
    enum token_enum {
        TOKEN_PARENTHS_OPEN,     TOKEN_PARENTHS_CLOSE,
        TOKEN_SPECIAL_DOT,       TOKEN_SPECIAL_QUOTE,
        TOKEN_LITERAL_NUM_INT,   TOKEN_LITERAL_STRING,
        TOKEN_LITERAL_NUM_FLOAT, TOKEN_SYMBOL,
        TOKEN_TOKENS // number of token types
    } type;

    union {
        char *symbol;
        char *string;
        long num_int;
        float num_float
    };
};

struct lexer {
    struct token *tokens;
    size_t tokens_cap;
    size_t ntokens;

    // identifier
    char iden[LEXER_IDEN_CAP];
    size_t iden_sz;

    int inside_string;
};

// allocate a lexer with a maximum number of tokens_cap tokens
// returns a lexer on success, NULL on fail
lexer_t lexer_create(size_t tokens_cap);

// destroy a lexer
void lexer_destroy(lexer_t lexer);

// turn the given non-null-terminated string str of lenght len
// into into tokens
// returns 0 on success
int lexer_tokenize(lexer_t lexer, char *str, size_t len);

#ifdef DEBUG
void lexer_print_tokens(lexer_t lexer);
#endif

#endif