<div dir="ltr">Thank you Julien and Raghu.</div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 16 Jan 2023 at 11:17, Julien Fischer <<a href="mailto:jfischer@opturion.com">jfischer@opturion.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"> Hi, On Fri, 13 Jan 2023, Modestas Valauskas wrote: > I'm looking for a formal grammar for Mercury. I'm thinking of a > declarative specification in the form of e.g. BNF/EBNF or perhaps > ANTLR or a different parser generator tool, but if that is not > available, anything else that would allow me to more easily write a > formal grammar for Mercury would be appreciated. There isn't one written down in a single spot, so far as I am aware. Some of it scattered throughout the reference manual -- the version from recent ROTDs is probably more useful in this respect than the current release. The way Mercury is parsed is a little unusual (mainly for historical reasons). The main steps are: 1. Tokenization (done by library/mercury_term_lexer.m). 2. Parsing the token stream into terms (done by libary/mercury_term_parser.m and related modules.) 3. Parsing of terms into items (declarations and clauses). The compiler design document (in compiler/notes/compiler_design.html) describes this in more detail and provides pointers to the relevant bits of code. Julien. </blockquote></div>