lexical description problem in language report?
Thomas Hallgren
hallgren@cse.ogi.edu
Mon, 23 Jul 2001 22:12:01 -0700
Memovich, Gary wrote:
> ... in section 2.3 where it is claimed that the string "{-" is a
> lexeme. However the string "{-" cannot be produced by the given
> grammar production. ...
>
There seems to be a similar problem with qualified identifiers. The
production for lexeme includes varid, conid, etc, rather than qvarid,
qconid, etc. (Perhaps someone forgot to update it when qualified names
were introduced, in Haskell 1.3...)
This might lead you to believe that qualified names are part of the
context-free syntax rather than the lexical syntax, and hence that
spaces are allowed in them. Qualified names are discussed briefly near
the end of section 2.4, but their lexical properties are not explained
here. Instead the reader is refered to section 5.3. This reference
probably meant to lead to 5.5.1, where the text makes it clear that
qualified names are part of the lexical syntax.
The same problem is present in Appendix B.
Suggestions: include qvarid, qconid in the production for lexeme. Move
the explanation of the lexical properties of qualified names from
section 5.5.1 to section 2.4.
Thomas Hallgren