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(* Copyright (c) 2008, Adam Chlipala
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - The names of contributors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*)
(* Lexing info for Laconic/Web programs *)
type pos = int
type svalue = Tokens.svalue
type ('a,'b) token = ('a,'b) Tokens.token
type lexresult = (svalue,pos) Tokens.token
local
val commentLevel = ref 0
val commentPos = ref 0
in
fun enterComment pos =
(if !commentLevel = 0 then
commentPos := pos
else
();
commentLevel := !commentLevel + 1)
fun exitComment () =
(ignore (commentLevel := !commentLevel - 1);
!commentLevel = 0)
fun eof () =
let
val pos = ErrorMsg.lastLineStart ()
in
if !commentLevel > 0 then
ErrorMsg.errorAt' (!commentPos, !commentPos) "Unterminated comment"
else
();
Tokens.EOF (pos, pos)
end
end
%%
%header (functor LacwebLexFn(structure Tokens : Lacweb_TOKENS));
%full
%s COMMENT;
id = [a-z_][A-Za-z0-9_]*;
cid = [A-Z][A-Za-z0-9_]*;
ws = [\ \t\012];
%%
<INITIAL> \n => (ErrorMsg.newline yypos;
continue ());
<COMMENT> \n => (ErrorMsg.newline yypos;
continue ());
<INITIAL> {ws}+ => (lex ());
<INITIAL> "(*" => (YYBEGIN COMMENT;
enterComment yypos;
continue ());
<INITIAL> "*)" => (ErrorMsg.errorAt' (yypos, yypos) "Unbalanced comments";
continue ());
<COMMENT> "(*" => (enterComment yypos;
continue ());
<COMMENT> "*)" => (if exitComment () then YYBEGIN INITIAL else ();
continue ());
<INITIAL> "(" => (Tokens.LPAREN (yypos, yypos + size yytext));
<INITIAL> ")" => (Tokens.RPAREN (yypos, yypos + size yytext));
<INITIAL> "[" => (Tokens.LBRACK (yypos, yypos + size yytext));
<INITIAL> "]" => (Tokens.RBRACK (yypos, yypos + size yytext));
<INITIAL> "{" => (Tokens.LBRACE (yypos, yypos + size yytext));
<INITIAL> "}" => (Tokens.RBRACE (yypos, yypos + size yytext));
<INITIAL> "->" => (Tokens.ARROW (yypos, yypos + size yytext));
<INITIAL> "=>" => (Tokens.DARROW (yypos, yypos + size yytext));
<INITIAL> "++" => (Tokens.PLUSPLUS (yypos, yypos + size yytext));
<INITIAL> "=" => (Tokens.EQ (yypos, yypos + size yytext));
<INITIAL> "," => (Tokens.COMMA (yypos, yypos + size yytext));
<INITIAL> ":::" => (Tokens.TCOLON (yypos, yypos + size yytext));
<INITIAL> "::" => (Tokens.DCOLON (yypos, yypos + size yytext));
<INITIAL> ":" => (Tokens.COLON (yypos, yypos + size yytext));
<INITIAL> "." => (Tokens.DOT (yypos, yypos + size yytext));
<INITIAL> "$" => (Tokens.DOLLAR (yypos, yypos + size yytext));
<INITIAL> "#" => (Tokens.HASH (yypos, yypos + size yytext));
<INITIAL> "con" => (Tokens.CON (yypos, yypos + size yytext));
<INITIAL> "fn" => (Tokens.FN (yypos, yypos + size yytext));
<INITIAL> "Type" => (Tokens.TYPE (yypos, yypos + size yytext));
<INITIAL> "Name" => (Tokens.NAME (yypos, yypos + size yytext));
<INITIAL> {id} => (Tokens.SYMBOL (yytext, yypos, yypos + size yytext));
<INITIAL> {cid} => (Tokens.CSYMBOL (yytext, yypos, yypos + size yytext));
<COMMENT> . => (continue());
<INITIAL> . => (ErrorMsg.errorAt' (yypos, yypos)
("illegal character: \"" ^ yytext ^ "\"");
continue ());
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