scanner.h

#ifndef clox_scanner_h
#define clox_scanner_h

#include "machine.h"

typedef enum {
    // single character punctuation, printed as expected characters
    TOKEN_LEFT_PAREN, TOKEN_RIGHT_PAREN,
    TOKEN_LEFT_BRACE, TOKEN_RIGHT_BRACE,
    TOKEN_LEFT_BRACKET, TOKEN_RIGHT_BRACKET,
    TOKEN_COMMA, TOKEN_DOT, TOKEN_SEMICOLON, TOKEN_COLON,
    TOKEN_EQUAL,

    // single character operators
    TOKEN_PLUS, TOKEN_MINUS, TOKEN_STAR, TOKEN_SLASH, TOKEN_BACKSLASH,
    TOKEN_AT, TOKEN_HAT, TOKEN_BANG, TOKEN_GREATER, TOKEN_LESS,

    // double character operators
    TOKEN_BANG_EQUAL, TOKEN_EQUAL_EQUAL, TOKEN_GREATER_EQUAL, TOKEN_LESS_EQUAL,
    TOKEN_DOT_DOT, TOKEN_ARROW,

    // literals
    TOKEN_IDENTIFIER, TOKEN_STRING, TOKEN_INT, TOKEN_REAL,

    // specials
    TOKEN_ERROR, TOKEN_EOF,

    // keywords not starting declarations
    TOKEN_AND, TOKEN_DYNVAR, TOKEN_ELSE, TOKEN_FALSE, TOKEN_HANDLE, TOKEN_NIL,
    TOKEN_OR, TOKEN_SUPER, TOKEN_THIS, TOKEN_TRUE, TOKEN_WHEN,

    // keywords starting declarations or statements allowing to sync parser after syntax error
    TOKEN_BREAK, TOKEN_CASE, TOKEN_CLASS, TOKEN_FOR, TOKEN_FUN,
    TOKEN_IF, TOKEN_PRINT, TOKEN_RETURN, TOKEN_VAR, TOKEN_WHILE,
} TokenType;

// For printing syntax errors in consumeExp(), first group of TokenType
#define TOKEN_CHARS "(){}[],.;:="

// The IDE68K compiler has a bug when returning structs by value, which are smaller
// than 3 longs. In this case, very strange FMOVE instructions are generated, which
// trap on the 68008 of course. So the Token struct must be at least 12 bytes long,
// which is somewhat wasteful... 

typedef struct {
    const char* start;
    TokenType   type;
    int16_t     length;
    int32_t     line; 
} Token;

void  initScanner(const char* source);
Token scanToken(void);

#endif