Parsing code.

[patrink]

I started working on a small programming language as a spare time project and I have created most of the functions (for input, output, variables, etc) except for the first step (ie, parsing the language and splitting it into tokens which my functions can use)

I've been having a few problems parsing the code. I honestly am not sure how to create a function to parse different strings.

For example:

int x = 3 + 3;
//parsed as: TYPE = "int", VAR = "x", VALUE = "3 + 3"
double y;
//parsed as: TYPE = "double", VAR = "y", VALUE = NULL

splitting the code doesn't work as well as I want as it will split the string differently depending on how the code was typed.

For example:

int x=3+3;
//when split with a space, you get "int" and "x=3+3;"
int x = 3 + 3 ;
//when split with a space, you get "int", "x", "=", "3", "+", "3", ";"

Long story short, am I just doing something wrong, or is there a different way to parse code which I haven't learned?

[whiteflags]

>int x=3+3;
>//when split with a space, you get "int" and "x=3+3;"

Maybe you should split the assignment symbol first, then you get "int x" and "3+3;" no matter really how it's typed.

>int x = 3 + 3 ;
>//when split with a space, you get "int", "x", "=", "3", "+", "3", ";"

Then you can re-enter the "int x" and "3+3;" tokens to get that. Or whatever you really want.

There's also this Parsing a String into Tokens Using strcspn 1 - C which will help you keep important parts of the language.

[AndrewHunter]

This is actually a huge topic. You are going to want to google "lexical analysis". To get you started you may find some use with:
the LEX and YACC page.
Programming Language Design
Algorithmic Languages and Compilers

The last two are courses however they contain many useful links to free online books and software.

[whiteflags]

Well who wants to write a compiler anyway?!

[AndrewHunter]

Well who wants to write a compiler anyway?!

Haha....well evidently the OP does. That is until he realizes you have to be a masochist to actually want to make one.

[patrink]

To be fair, its an interpreter, not a compiler. Compilers require even more code and even more time.

Thanks for all the links though, I'll check them all out.