#ifndef __USCRIPT_LEX_H__
#define __USCRIPT_LEX_H__

#include "common.h"
#include "val.h"

#define XTOKENS(_) \
        _(BREAK) \
        _(DIV_EQL) \
        _(DO) \
        _(DOT_DOT) \
        _(ELSE) \
        _(ELSEIF) \
        _(END) \
        _(EQL) \
        _(ERR) \
        _(FALSE) \
        _(FUN) \
        _(GLOBAL) \
        _(GTEQL) \
        _(IDENT) \
        _(IF) \
        _(IN) \
        _(LET) \
        _(LOOP) \
        _(LTEQL) \
        _(MINUS_EQL) \
        _(MOD) \
        _(MOD_EQL) \
        _(MULT_EQL) \
        _(NEQL) \
        _(NEXT) \
        _(NUM) \
        _(PLUS_EQL) \
        _(RET) \
        _(STR) \
        _(TRUE) \
        _(ZILCH)

// single-character tokens are represented by their ASCII value, but other types
// of tokens are represented by a token_kind enum value.
enum token_kind {
        TOKEN_EOF = 256,
#define DEF_TOKEN_ENUM(name) TOKEN_##name,
        XTOKENS(DEF_TOKEN_ENUM)
#undef DEF_TOKEN_ENUM
};

struct lexer {
        const char *src;
        const char *base;
        const char *head;

        int line;
        int col;
};

struct token {
        const char *start;
        int len;
        int line;
        int col;
        u16 kind;
        struct us_val val;
};

void lex_init(struct lexer *lex, const char *src);
struct token lex_next_token(struct lexer *lex);

void token_kind_name(char *dst, size_t len, u16 kind);
void print_token(struct token tok);

#endif // __USCRIPT_LEX_H__