[erlang-questions] Leex - a lexical anaylzer generator, released

Robert Virding <>
Mon May 26 17:10:33 CEST 2008


2008/5/26 zambal <>:

> Hi Robert,
>
> I have totally no experience with lex or any other tools in this
> class,
> but out of curiosity I was reading lfe_scan.xrl and was wondering what
> these #' #` #; #, and #,@ separator rules are for. Are these just
> reserved for later use or are they part of some undocumented syntax?


These are taken from Scheme R6RS and will most likely go as LFE has no use
for them.

#' #` #, #,@ are for use in syntax-case macros and mean:

#'  - (syntax ...)
#`  - (quasisyntax ...)
#,  - (unsyntax ...)
#,@ - (unsyntax-splicing ...)

#; - comment out next sepxr which could actually be useful

Also I missed #| ... |# for block comments. Might also be useful. Question
is if block comments are token or character based?

Be glad I didn't adopt R6RS symbol syntax, it is complex and full of special
cases. :-) I think having that if an (lisp) atom can be parsed as a number
then it is a number, else it is a symbol is much easier.

Glad you enjoy LFE.

Robert
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