#include "tokenizer.h"

Tokenizer initTokenizer(const char *source) {
    int line = source ? 1 : 0;
    return (Tokenizer) {source, line};
}

static bool isWhitespace(char c) {
    switch (c) {
        case '\n':
        case ' ':
        case '\r':
        case '\t':
            return true;
        default:
            return false;
    }
}

static void skipWhitespace(Tokenizer *tokenizer) {
    while (1) {
        char c = *tokenizer->current;
        if (c == '\n') {
            tokenizer->line++;
            continue;
        }
        if (!isWhitespace(c))
            break;
    }
}

Token scanToken(Tokenizer *tokenizer) {
    skipWhitespace(tokenizer);
    Token token = {tokenizer->current, 0, tokenizer->line};

    if (*tokenizer->current == '\0') {
        token.start = NULL;
        return token;
    }

    while (!isWhitespace(*tokenizer->current) || *tokenizer->current != '\0') {
        tokenizer->current++;
    }
    token.length = (int) (tokenizer->current - token.start);

    return token;
}