Example parsers to learn how to write them [closed]

Question

I am looking for source codes of parsers and/or parser generators that could be studied in order to develop further, my skills that I acquired during a school course. Do you know any recommendable parsers of any type?

Answer 1

You should know how to build recursive descent parsers by hand. Here's an SO link to a quick lesson on how to do this: https://stackoverflow.com/a/2336769/120163

If you want to understand how recursive descent parsers can be constructed automatically, you can read a paper (and see a tutorial) on MetaII at this link: https://stackoverflow.com/a/1142034/120163

Answer 2

• Bison is a classical example (C/C++).
• Pyparsing is a great module, and it is very easy to use (Python) .
• Lemon is very easy to use (C++).

Check the examples, and good luck.

Edit:

I guess I should comment. A parser is a program which processes an input and "understands" it. A parser generator is a tool used to write parsers. I guess you mean you want to learn more about generating parsers, in which case, you should refer to the documentation of parser generators (all of the above).

Answer 3

Parsers themselves are usually not that interesting, it's the generators of parsers that are more of a subject of study.

• ANTLR generates LL parsers which are easily readable once generated. (Java)
• Bison generates LALR(1) parsers which are impossible to read. (C)

If LALR(1) interests you, I have a library up on github that tries to do a new number on LALR parsing. Feel free to take a look. It's in C# and I've tried my finest to make the code comprehensible. It's been a learning project for me, but it's smaller than the big tools and a bit easier to penetrate. And definitely feel free to contribute, lots of features to add still.

Otherwise, take a look at the generated code of these tools to see how they build the actual parsers that do the work.