How to handle comments using API

[twitu]

I found the API difficult to implement if followed to the word. Particularly while handling comments.

The hasMoreCommands() returns a boolean but it must know the content of the line to determine if it is a comment or not. This effectively makes advance() function useless.

How do i resolve this issue ?

[cadet1620]

Yes, strict implementation of this interface requires hasMoreCommands() to read lines and strip comments and whitespace and only return when it has found a non-blank line or end of file.

I combined hasMoreCommands() into advance() and had advance() return true/false so that my pass1/pass2 loops can simple be "while(parser.advance()) {"

Another thing that I've seen students do, especially in languages like Python that make list manipulation really simple, is to read the entire source file into a list, then strip all the comments and whitespace, then delete any blank lines that may result.

I don't like this pre-stripping because if you later wish to modify your assembler to add source line number information to error messages, or generate a listing file, you have lost all that info.

--Mark