Question

I need to translate programs written in a domain specific language into xml representation. These programs are in the form of simple text file. What approach would you suggest me? What api should I use to:

1. Parse the text files written in this language.
2. Write xml based on the token and token streams I obtain.

My criteria is more of a rapid and easier development rather then memory or computing time efficiency.

Many Thanks
Ketan

Answer 1

The less trivial part of the job is with step #1, parsing the Domain Specific Language (DSL) text, rather than #2, pushing this to some XML language.

Hopefully you readily have a parser for the DSL (obviously this language must have been put to use somewhere…), and you may be able to “hook” your export/conversion logic into this parser. If such is not possible, you’ll need to write a new parser.

Depending on the complexity of the DSL, you may be able to write, longhand, a simple parser based on a few loops and switch cases.
For more complicated languages, ANTLR is often a good choice. In a nutshell, one formalize the grammar of the DSL, in Backus Naur Form (BNF, or actually EBNF, here, i.e. the Extended family) and ANTLR produces a parser, written in a target language of choice (including Java). The learning curve with ANTLR is a factor to consider but in the context of a moderately to extremely sophisticated language, a well worth investment. ANTLR is similar but, in my opinion, a better tool than GNU Bison, this latter would however do the trick as well, and too, target Java is so desired.
If you are familiar with other languages, in particular Python, there are many other tools that can be put to use for more or less ad-hoc parsers; I’ve also used PyParsing and gladly recommend it.