/* lexer.h -- simple tokeniser for Micro Python
 *
 * Uses (byte) length instead of null termination.
 * Tokens are the same - UTF-8 with (byte) length.
 */

typedef enum _mp_token_kind_t {
    MP_TOKEN_END,                   // 0

    MP_TOKEN_INVALID,
    MP_TOKEN_DEDENT_MISMATCH,
    MP_TOKEN_LONELY_STRING_OPEN,
    MP_TOKEN_BAD_LINE_CONTINUATION,

    MP_TOKEN_NEWLINE,               // 5
    MP_TOKEN_INDENT,                // 6
    MP_TOKEN_DEDENT,                // 7

    MP_TOKEN_NAME,                  // 8
    MP_TOKEN_NUMBER,
    MP_TOKEN_STRING,
    MP_TOKEN_BYTES,

    MP_TOKEN_ELLIPSIS,

    MP_TOKEN_KW_FALSE,              // 13
    MP_TOKEN_KW_NONE,
    MP_TOKEN_KW_TRUE,
    MP_TOKEN_KW_AND,
    MP_TOKEN_KW_AS,
    MP_TOKEN_KW_ASSERT,
    MP_TOKEN_KW_BREAK,
    MP_TOKEN_KW_CLASS,
    MP_TOKEN_KW_CONTINUE,
    MP_TOKEN_KW_DEF,                // 22
    MP_TOKEN_KW_DEL,
    MP_TOKEN_KW_ELIF,
    MP_TOKEN_KW_ELSE,
    MP_TOKEN_KW_EXCEPT,
    MP_TOKEN_KW_FINALLY,
    MP_TOKEN_KW_FOR,
    MP_TOKEN_KW_FROM,
    MP_TOKEN_KW_GLOBAL,
    MP_TOKEN_KW_IF,
    MP_TOKEN_KW_IMPORT,             // 32
    MP_TOKEN_KW_IN,
    MP_TOKEN_KW_IS,
    MP_TOKEN_KW_LAMBDA,
    MP_TOKEN_KW_NONLOCAL,
    MP_TOKEN_KW_NOT,
    MP_TOKEN_KW_OR,
    MP_TOKEN_KW_PASS,
    MP_TOKEN_KW_RAISE,
    MP_TOKEN_KW_RETURN,
    MP_TOKEN_KW_TRY,                // 42
    MP_TOKEN_KW_WHILE,
    MP_TOKEN_KW_WITH,
    MP_TOKEN_KW_YIELD,

    MP_TOKEN_OP_PLUS,               // 46
    MP_TOKEN_OP_MINUS,
    MP_TOKEN_OP_STAR,
    MP_TOKEN_OP_DBL_STAR,
    MP_TOKEN_OP_SLASH,
    MP_TOKEN_OP_DBL_SLASH,
    MP_TOKEN_OP_PERCENT,
    MP_TOKEN_OP_LESS,
    MP_TOKEN_OP_DBL_LESS,
    MP_TOKEN_OP_MORE,
    MP_TOKEN_OP_DBL_MORE,           // 56
    MP_TOKEN_OP_AMPERSAND,
    MP_TOKEN_OP_PIPE,
    MP_TOKEN_OP_CARET,
    MP_TOKEN_OP_TILDE,
    MP_TOKEN_OP_LESS_EQUAL,
    MP_TOKEN_OP_MORE_EQUAL,
    MP_TOKEN_OP_DBL_EQUAL,
    MP_TOKEN_OP_NOT_EQUAL,

    MP_TOKEN_DEL_PAREN_OPEN,        // 65
    MP_TOKEN_DEL_PAREN_CLOSE,
    MP_TOKEN_DEL_BRACKET_OPEN,
    MP_TOKEN_DEL_BRACKET_CLOSE,
    MP_TOKEN_DEL_BRACE_OPEN,
    MP_TOKEN_DEL_BRACE_CLOSE,
    MP_TOKEN_DEL_COMMA,
    MP_TOKEN_DEL_COLON,
    MP_TOKEN_DEL_PERIOD,
    MP_TOKEN_DEL_SEMICOLON,
    MP_TOKEN_DEL_AT,                // 75
    MP_TOKEN_DEL_EQUAL,
    MP_TOKEN_DEL_PLUS_EQUAL,
    MP_TOKEN_DEL_MINUS_EQUAL,
    MP_TOKEN_DEL_STAR_EQUAL,
    MP_TOKEN_DEL_SLASH_EQUAL,
    MP_TOKEN_DEL_DBL_SLASH_EQUAL,
    MP_TOKEN_DEL_PERCENT_EQUAL,
    MP_TOKEN_DEL_AMPERSAND_EQUAL,
    MP_TOKEN_DEL_PIPE_EQUAL,
    MP_TOKEN_DEL_CARET_EQUAL,       // 85
    MP_TOKEN_DEL_DBL_MORE_EQUAL,
    MP_TOKEN_DEL_DBL_LESS_EQUAL,
    MP_TOKEN_DEL_DBL_STAR_EQUAL,
    MP_TOKEN_DEL_MINUS_MORE,
} mp_token_kind_t;

typedef struct _mp_token_t {
    const char *src_name;       // name of source
    uint src_line;              // source line
    uint src_column;            // source column

    mp_token_kind_t kind;       // kind of token
    const char *str;            // string of token (valid only while this token is current token)
    uint len;                   // (byte) length of string of token
} mp_token_t;

// the next-char function must return the next character in the stream
// it must return MP_LEXER_CHAR_EOF if end of stream
// it can be called again after returning MP_LEXER_CHAR_EOF, and in that case must return MP_LEXER_CHAR_EOF
#define MP_LEXER_CHAR_EOF (-1)
typedef unichar (*mp_lexer_stream_next_char_t)(void*);
typedef void (*mp_lexer_stream_close_t)(void*);

typedef struct _mp_lexer_t mp_lexer_t;

void mp_token_show(const mp_token_t *tok);
void mp_token_show_error_prefix(const mp_token_t *tok);
bool mp_token_show_error(const mp_token_t *tok, const char *msg);

mp_lexer_t *mp_lexer_new(const char *src_name, void *stream_data, mp_lexer_stream_next_char_t stream_next_char, mp_lexer_stream_close_t stream_close);
mp_lexer_t *mp_lexer_new_from_str_len(const char *src_name, const char *str, uint len, uint free_len);

void mp_lexer_free(mp_lexer_t *lex);
void mp_lexer_to_next(mp_lexer_t *lex);
const mp_token_t *mp_lexer_cur(const mp_lexer_t *lex);
bool mp_lexer_is_kind(mp_lexer_t *lex, mp_token_kind_t kind);
/* unused
bool mp_lexer_is_str(mp_lexer_t *lex, const char *str);
bool mp_lexer_opt_kind(mp_lexer_t *lex, mp_token_kind_t kind);
bool mp_lexer_opt_str(mp_lexer_t *lex, const char *str);
*/
bool mp_lexer_show_error(mp_lexer_t *lex, const char *msg);
bool mp_lexer_show_error_pythonic(mp_lexer_t *lex, const char *msg);

// used to import a module; must be implemented for a specific port
mp_lexer_t *mp_import_open_file(qstr mod_name);