Antlr4 grammars for ElmerSolver

[F. S. Farimani]

Hello everyone,

I have been looking into the ANTLR4 project for the last couple of days and I opened this issue On Elmer's repository recently. Now I want to start writing the EBNF syntax for ElmerSolver myself.

I was wondering if you could give me an example close to ElmerSpolver .sif files (chapter 2 of this PDF). The first step for me is to learn how I can create the lexer/parser grammars for blocks that start with keywords such as

• Header
• Simulation
• Constants
• Body <integer>
• Material<integer>
• Body Force <integer>
• Equation <integer>
• Solver <integer>
• Boundary Condition <integer>
• Initial Condition <integer>
• Component <integer>

and end with an "End" keyword.

Thanks for your support in advance and looking forward to hearing back.

Best,

F.

[Susan Jolly]

When I started using ANTLR I was retired from a career as a computational
scientist, had extensive experience with programming in Java, and was very
familiar with the domain in which I wanted to take advantage of ANTLR.
However I had no experience with parsing. Looking back there is no way I
would have succeeded in achieving my goal without a careful and
time-consuming study of Terence Parr's "The Definitive ANTLR 4 Reference."
For me the key conceptual breakthrough was figuring out how to take
advantage of the information about annotating parse-tree nodes which is at
the bottom of page 123. YMMV of course.

Best wishes.

[rtm...@googlemail.com]

Agreed with this. Grab the book and start reading.

For a grammar like yours it seems simple. Here are a lot of sample grammars <https://github.com/antlr/grammars-v4>, pick a language you're familiar with then look at the corresponding grammar and note how the grammar closely follows the language. Antlr is very flexible with its input.

Unfortunately I can't suggest something that looks like what you want, the Elmer stuff, but if you're familiar with eg. java, look at the java grammar. But read the book also.

cheers

jan