Re: [Caml-list] single-line comment request

[Thierry SALSET <ts@cermics.enpc.fr>]

[-- Attachment #1: Type: Text/Plain, Size: 875 bytes --]

>>>>> "Samuel" == Samuel Lacas <Samuel.Lacas@trusted-logic.fr> writes:

    Samuel> Nickolay Semyonov-Kolchin a écrit 0.5K le Tue, Apr 08, 2003
    Samuel> at 05:56:05PM +0500: Hi, I really want single-line comment
    Samuel> in Ocaml. Peter Weis (sorry, if I typed name wrong) several
    Samuel> time ago said that "there is no suitable character for
    Samuel> single line comment". Why don't use double '#'? I.e. '##'.
    Samuel> Single line comment let _ = ## Another single line comment
    Samuel> ...

    Samuel> Hmm, may be a "simple" camlp4 extension can cater for your
    Samuel> need, though I personnally never explored camlp4 in depth...

Comments are processed by the lexer, so a simple extension to the camlp4
lexer should allow that. A patch to camlp4/lib/plexer.ml (O'Caml 3.06)
follows.

      Thierry Salset
      CERMICS / ENPC


[-- Attachment #2: plexer.diff --]
[-- Type: Text/Plain, Size: 1363 bytes --]

*** camlp4/lib/plexer.ml	Fri Jul 19 16:53:48 2002
--- camlp4/lib/patched/plexer.ml	Wed Apr  9 17:10:26 2003
***************
*** 127,133 ****
      [ [: `' ' | '\010' | '\013' | '\t' | '\026' | '\012'; s :] ->
          next_token s
      | [: `'('; s :] -> left_paren bp s
!     | [: `'#'; s :] -> do { spaces_tabs s; linenum bp s }
      | [: `('A'..'Z' | '\192'..'\214' | '\216'..'\222' as c); s :] ->
          let id = get_buff (ident (store 0 c) s) in
          let loc = (bp, Stream.count s) in
--- 127,133 ----
      [ [: `' ' | '\010' | '\013' | '\t' | '\026' | '\012'; s :] ->
          next_token s
      | [: `'('; s :] -> left_paren bp s
!     | [: `'#'; s :] -> sharp bp s
      | [: `('A'..'Z' | '\192'..'\214' | '\216'..'\222' as c); s :] ->
          let id = get_buff (ident (store 0 c) s) in
          let loc = (bp, Stream.count s) in
***************
*** 327,332 ****
--- 327,340 ----
      parser
      [ [: `'>' :] -> len
      | [: a = quotation bp (store len '>') :] -> a ]
+   and sharp bp = 
+     parser
+     [ [: `'#'; _ = one_line_comment bp  ; a = next_token :] -> a
+     | [: s :] -> do { spaces_tabs s; linenum bp s } ]
+   and one_line_comment bp = 
+     parser
+     [ [: `'\n' :] -> ()
+     | [: `_; s :] -> one_line_comment bp s ]
    and left_paren bp =
      parser
      [ [: `'*'; _ = comment bp; a = next_token :] -> a