[PATCH] Support i18n of the parse error messages.

[Akim Demaille]

        * TODO (lalr1.cc/I18n): Remove.
        * data/lalr1.cc (yysyntax_error_): Support the translation of the
        error messages, as done in yacc.c.
        Stay within the yy* pseudo namespace.
---
 ChangeLog     |    8 ++++++
 TODO          |    4 ---
 data/lalr1.cc |   77 +++++++++++++++++++++++++++++++++++---------------------
 3 files changed, 56 insertions(+), 33 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8f97372..fad6f31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2008-11-11  Akim Demaille  <address@hidden>
 
+       Support i18n of the parse error messages.
+       * TODO (lalr1.cc/I18n): Remove.
+       * data/lalr1.cc (yysyntax_error_): Support the translation of the
+       error messages, as done in yacc.c.
+       Stay within the yy* pseudo namespace.
+
+2008-11-11  Akim Demaille  <address@hidden>
+
        More TODO.
        * TODO (single stack, yysyntax_error): New.
 
diff --git a/TODO b/TODO
index ae89c92..1b9aaed 100644
--- a/TODO
+++ b/TODO
@@ -106,10 +106,6 @@ find something clean (not like YYLSP_NEEDED...).
 Before releasing, make sure the documentation ("Understanding your
 parser") refers to the current `output' format.
 
-* lalr1.cc
-** I18n
-Catch up with yacc.c.
-
 * Report
 
 **  GLR
diff --git a/data/lalr1.cc b/data/lalr1.cc
index 5a9d5c0..bacdf37 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -1385,9 +1385,9 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
   // Generate an error message.
   std::string
   ]b4_parser_class_name[::yysyntax_error_ (int yystate, int]dnl
-b4_error_verbose_if([ tok])[)
+b4_error_verbose_if([ yytoken])[)
   {
-    std::string res;
+    std::string yyres;
     YYUSE (yystate);
 #if YYERROR_VERBOSE
     int yyn = yypact_[yystate];
@@ -1400,36 +1400,55 @@ b4_error_verbose_if([ tok])[)
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
-       int count = 0;
-       for (int x = yyxbegin; x < yyxend; ++x)
-         if (yycheck_[x + yyn] == x && x != yyterror_)
-           ++count;
-
-       // FIXME: This method of building the message is not compatible
-       // with internationalization.  It should work like yacc.c does it.
-       // That is, first build a string that looks like this:
-       // "syntax error, unexpected %s or %s or %s"
-       // Then, invoke YY_ on this string.
-       // Finally, use the string as a format to output
-       // yytname_[tok], etc.
-       // Until this gets fixed, this message appears in English only.
-       res = "syntax error, unexpected ";
-       res += yytnamerr_ (yytname_[tok]);
-       if (count < 5)
-         {
-           count = 0;
-           for (int x = yyxbegin; x < yyxend; ++x)
-             if (yycheck_[x + yyn] == x && x != yyterror_)
-               {
-                 res += (!count++) ? ", expecting " : " or ";
-                 res += yytnamerr_ (yytname_[x]);
-               }
-         }
+
+        // Number of "expected" tokens.
+       size_t yycount = 0;
+        // Its maximum.
+        enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
+        // Arguments of yyformat.
+        char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
+        yyarg[yycount++] = yytname_[yytoken];
+       for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
+         if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_)
+          {
+            if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
+            {
+              yycount = 1;
+              break;
+            }
+            else
+              yyarg[yycount++] = yytname_[yyx];
+          }
+
+        char const* yyformat = 0;
+        switch (yycount)
+        {
+#define YYCASE_(N, S)                           \
+          case N:                               \
+            yyformat = S;                       \
+          break
+          YYCASE_(1, YY_("syntax error, unexpected %s"));
+          YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s"));
+          YYCASE_(3, YY_("syntax error, unexpected %s, expecting %s or %s"));
+          YYCASE_(4, YY_("syntax error, unexpected %s, expecting %s or %s or 
%s"));
+          YYCASE_(5, YY_("syntax error, unexpected %s, expecting %s or %s or 
%s or %s"));
+#undef YYCASE_
+        }
+        // Argument number.
+        size_t yyi = 0;
+        for (char const* yyp = yyformat; *yyp; ++yyp)
+          if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
+          {
+            yyres += yytnamerr_ (yyarg[yyi++]);
+            ++yyp;
+          }
+          else
+            yyres += *yyp;
       }
     else
 #endif
-      res = YY_("syntax error");
-    return res;
+      yyres = YY_("syntax error");
+    return yyres;
   }
 
 
-- 
1.6.0.2.588.g3102