style: update comments in the skeletons

* data/skeletons/c++.m4, data/skeletons/glr.c, data/skeletons/lalr1.d,
* data/skeletons/lalr1.java, data/skeletons/yacc.c:
Be more accurate about yychar and yytoken.
Don't name local variables as if they were members.

data/skeletons/c++.m4

@@ -594,11 +594,12 @@ m4_define([b4_yytranslate_define],
     {
   ]b4_translate[
     };
-    const int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    const int code_max = ]b4_code_max[;
 
     if (t <= 0)
       return symbol_kind::]b4_symbol_prefix[YYEOF;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       return YY_CAST (symbol_kind_type, translate_table[t]);
     else
       return symbol_kind::]b4_symbol_prefix[YYUNDEF;]])[

data/skeletons/glr.c

@@ -333,7 +333,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
    accessed by $0, $-1, etc., in any rule.  */
 #define YYMAXLEFT ]b4_max_left_semantic_context[
 
-/* YYMAXUTOK -- Last valid token number (for yychar).  */
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   ]b4_code_max[
 
 /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM

data/skeletons/lalr1.d

@@ -428,8 +428,9 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
    */
   public bool parse ()
   {
-    /// Lookahead and lookahead in internal form.
+    // Lookahead token kind.
     int yychar = TokenKind.YYEMPTY;
+    // Lookahead symbol kind.
     SymbolKind yytoken = ]b4_symbol(-2, kind)[;
 
     /* State.  */
@@ -841,11 +842,12 @@ m4_popdef([b4_at_dollar])])dnl
   ]b4_translate[
     @};
 
-    immutable int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    immutable int code_max = ]b4_code_max[;
 
     if (t <= 0)
       return ]b4_symbol(0, kind)[;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       {
         import std.conv : to;
         return to!SymbolKind (translate_table[t]);

data/skeletons/lalr1.java

@@ -53,8 +53,9 @@ b4_use_push_for_pull_if([
 # allows them to be defined either in parse() when doing pull parsing,
 # or as class instance variable when doing push parsing.
 m4_define([b4_define_state],[[
-    /* Lookahead and lookahead in internal form.  */
+    /* Lookahead token kind.  */
     int yychar = YYEMPTY_;
+    /* Lookahead symbol kind.  */
     SymbolKind yytoken = null;
 
     /* State.  */
@@ -1078,17 +1079,18 @@ b4_dollar_popdef[]dnl
 
   /* YYTRANSLATE_(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
      as returned by yylex, with out-of-bounds checking.  */
-  private static final SymbolKind yytranslate_ (int t)
+  private static final SymbolKind yytranslate_(int t)
 ]b4_api_token_raw_if(dnl
 [[  {
     return SymbolKind.get(t);
   }
 ]],
 [[  {
-    int code_max_ = ]b4_code_max[;
+    // Last valid token kind.
+    int code_max = ]b4_code_max[;
     if (t <= 0)
       return ]b4_symbol(0, kind)[;
-    else if (t <= code_max_)
+    else if (t <= code_max)
       return SymbolKind.get(yytranslate_table_[t]);
     else
       return ]b4_symbol(2, kind)[;

data/skeletons/yacc.c

@@ -155,7 +155,7 @@ m4_define([b4_rhs_location],
 # Declare the variables that are global, or local to YYPARSE if
 # pure-parser.
 m4_define([b4_declare_scanner_communication_variables], [[
-/* The lookahead symbol.  */
+/* Lookahead token kind.  */
 int yychar;
 
 ]b4_pure_if([[
@@ -571,6 +571,7 @@ union yyalloc
 /* YYNSTATES -- Number of states.  */
 #define YYNSTATES  ]b4_states_number[
 
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   ]b4_code_max[
 
 
@@ -1544,7 +1545,7 @@ yyparse (]m4_ifset([b4_parse_param], [b4_formals(b4_parse_param)], [void])[)]])[
   int yyn;
   /* The return value of yyparse.  */
   int yyresult;
-  /* Lookahead token as an internal (translated) token number.  */
+  /* Lookahead symbol kind.  */
   yysymbol_kind_t yytoken = ]b4_symbol(-2, kind)[;
   /* The variables used to return semantic value and location from the
      action routines.  */

src/parse-gram.c

@@ -627,6 +627,7 @@ union yyalloc
 /* YYNSTATES -- Number of states.  */
 #define YYNSTATES  167
 
+/* YYMAXUTOK -- Last valid token kind.  */
 #define YYMAXUTOK   315
 
 
@@ -1752,7 +1753,7 @@ yydestruct (const char *yymsg,
 int
 yyparse (void)
 {
-/* The lookahead symbol.  */
+/* Lookahead token kind.  */
 int yychar;
 
 
@@ -1807,7 +1808,7 @@ YYLTYPE yylloc = yyloc_default;
   int yyn;
   /* The return value of yyparse.  */
   int yyresult;
-  /* Lookahead token as an internal (translated) token number.  */
+  /* Lookahead symbol kind.  */
   yysymbol_kind_t yytoken = YYSYMBOL_YYEMPTY;
   /* The variables used to return semantic value and location from the
      action routines.  */