#include "scanner.h"
#include <string.h>

const char* source_code;
//Start and Current hold the offsets that index into the string source_code.
int start;   //Points to the first character in the lexeme being scanned.
int current; //points to the character currently being considered.
int length;
int line = 1;

char Advance(void);
int IsAtend(void);
void ScanToken(void);

void ScanTokens(const char* source) {
    if (!source) return;
    
    source_code = source;
    length = strlen(source);

    if (length == 0) return;

    while(!IsAtend()) {
        start = current;
        ScanToken();
    }

    //Add EOF token and return list once that's set up.
}

void ScanToken() {
    char c = Advance();

    switch (c) {
    case '(':
    case ')':
    case '{':
    case '}':
    case ',':
    case '.':
    case '-':
    case '+':
    case ';':
    case '*':
    break;
    }
}

int IsAtEnd() {
    return current >= length;
}

char Advance() {
    return source_code[current++];
}