Navigating through a text file?

Question

C++ / C#

It is necessary to organize movement on a file.
For example, lines are read up to a certain point, and then you need to read a line higher from the same file.
And so many times.
What for? I am writing an interpreter for my little language.
Before that, I just read everything into std::vector, but storing large files in RAM seems kind of bad. What can be used here?

Answer 1

If you are afraid to read entire files, you can use the memory-mapped file mechanism.

Answer 2

I have nothing to say specifically on this issue, but I can advise you to read the Book of the Dragon .
When designing things like this, very helpful.

Answer 3

It is better to convert the source into an intermediate code once (at least at the level of tokens) and work on it. There is no need to conduct a full analysis of the text every time.