#ifndef BDL_LEXER_H
#define BDL_LEXER_H

#include "string_view.h"

typedef enum TokenType {
    TOKEN_UNKNOWN = 0,

    // Parentheses.
    TOKEN_LPAREN,
    TOKEN_RPAREN,

    // Primitive types.
    TOKEN_FIXNUM,
    TOKEN_SYMBOL,
    TOKEN_STRING,
    TOKEN_NIL,
    TOKEN_TRUE,
    TOKEN_FALSE,

    // Keywords.
    TOKEN_LAMBDA,

    // End of file.
    TOKEN_EOF,
} TokenType;

typedef struct Token {
    TokenType type;
    StringView value;
    size_t line;
    size_t col;
} Token;

typedef struct Scanner {
    StringView current;
    size_t line_number;
    size_t col_number;
    size_t offset;
} Scanner;

// Print a token to standard output for debugging purposes.
void print_token(Token tok);

// Same functionality as the ScanView pairs, but keeping track of line and
// column numbers.
char scan_next(Scanner *scanner);
char scan_peek(const Scanner *scanner);

// Check if the current scanner still have characters left.
bool scan_has_next(const Scanner *scanner);

// Advance the scanner until we ran out of whitespace.
void skip_whitespace(Scanner *scanner);

// Check if a given character is a delimiter.
bool is_delimiter(char c);

// Extract the token type from the current string.
TokenType find_primitive_type(const StringView value);

// Generate a list of tokens from the given string.
Token * tokenize(const StringView *sv, Errors *errors);

#endif // BDL_LEXER_H