I am implementing a small programming language. Here is the codebase. The program is built with ocamlbuild. I added a parser using menhir. When I compile and run the program, I got the following message.
❱ ./main.byte
Fatal error: exception Parser.MenhirBasics.Error
I am trying to find more details by passing the explain to the _tag file
true: color(always), explain
but there doesn't seem to be any difference. How to I make menhir to generate a logging file through ocamlbuild? or other ways to debug?
This is syntax error raised by the parser generated by menhir.
Your build system is irrelevant (nevertheless, you should use dune for a new project and not ocamlbuild).
Similarly, the --explain flag of menhir is only useful for generating conflict explanations when generating the parser. It doesn't add syntax error explanation to syntax error.
If you want to debug a menhir grammar, you can use menhir intepreter mode with menhir --interpret
menhir --interpret parser.mly
or list all possible syntax errors in your grammar with menhir --list-errors.
menhir --list-errors parser.mly
Both options should make the reason why `"hi." is a syntax error in your grammar relatively clear.