From 4b3b7899f4503b9af1cb955f4c2315fa430d92d5 Mon Sep 17 00:00:00 2001
From: TYoko <tyoko-dev@users.noreply.github.com>
Date: Fri, 5 Feb 2016 13:17:31 +0900
Subject: [PATCH] Reserved symbols have a higher precedence than predefined
 tokens as in Haskell version.

-- The following file produces different results in Haskell and OCaml
versions.
{-
% bnfc -m -ocaml A.cf
% make
% echo ":a" | ./TestA
[Abstract syntax]

MyId (MyIdent ":a")

[Linearized tree]

:a
% bnfc -m -haskell A.cf
% make
% echo ":a" | ./TestA

Parse Successful!

[Abstract Syntax]

Keyword

[Linearized tree]

:a
-}

Keyword. Exp ::= ":a" ;
MyId.    Exp ::= MyIdent ;

token MyIdent (':' letter)
---
 source/src/BNFC/Backend/OCaml/CFtoOCamlLex.hs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/source/src/BNFC/Backend/OCaml/CFtoOCamlLex.hs b/source/src/BNFC/Backend/OCaml/CFtoOCamlLex.hs
index a5bdbcf8..c78eae41 100644
--- a/source/src/BNFC/Backend/OCaml/CFtoOCamlLex.hs
+++ b/source/src/BNFC/Backend/OCaml/CFtoOCamlLex.hs
@@ -193,16 +193,17 @@ rules cf = mkRule "token" $
     ++
     [ (mkRegexMultilineComment b e, "token lexbuf") | (b,e) <- multilineC]
     ++
+    -- reserved keywords
+    [ ( "rsyms"
+      , "let id = lexeme lexbuf in try Hashtbl.find symbol_table id with Not_found -> failwith (\"internal lexer error: reserved symbol \" ^ id ^ \" not found in hashtable\")" )
+      | not (null (cfgSymbols cf))]
+    ++
     -- user tokens
     [ (text n , tokenAction (text t)) | (n,_,t) <- userTokens cf]
     ++
     -- predefined tokens
     [ ( "l i*", tokenAction "Ident" ) ]
     ++
-    [ ( "rsyms"
-      , "let id = lexeme lexbuf in try Hashtbl.find symbol_table id with Not_found -> failwith (\"internal lexer error: reserved symbol \" ^ id ^ \" not found in hashtable\")" )
-      | not (null (cfgSymbols cf))]
-    ++
     -- integers
     [ ( "d+", "let i = lexeme lexbuf in TOK_Integer (int_of_string i)" )
     -- doubles