Provide more information in the tokenizer (added to the Token)

[Specy]

Most parsers have information on a token that tell you at what position the token is in. for example in this tokenized string (tokens separated by a |):

foo|(|bar|+|baz|)

foo: offset 0, len 3 (optional, can be derived from the slice itself
(: offset 3, len 1
bar: offset: 4, len 3

etc...
Other useful proprieties are start line, end line, start column, end column

Also, does the parser ignore whitespace? foo(bar+baz) and foo(bar + baz) tokenize the same.
The offset information is useful to create things like this:

I was calculating the offset myself but since whitespace seems to be ignored, the tokens positions are wrong, this would be solved with the offsets.

This should also help with #1

[umut-sahin]

Yeap, this should be done, for sure. I'll try to take a look this weekend.