d: minor clean up

* doc/bison.texi: Use @samp, not "...", around pieces of code.
* examples/d/calc/calc.y: Don't promote %union.

doc/bison.texi

@@ -6484,8 +6484,7 @@ with other members of the @code{SymbolKind} class.
 
 
 @item Default Value:
-@code{YYSYMBOL_} in C.  @code{S_} in C++ and Java.  The default prefix is
-removed from D.
+@code{YYSYMBOL_} in C, @code{S_} in C++ and Java, empty in D.
 @item History:
 introduced in Bison 3.6.
 @end itemize
@@ -6503,9 +6502,9 @@ C++, D
 @item Purpose:
 Request that symbols be handled as a whole (type, value, and possibly
 location) in the scanner. In the case of C++, it works only when
-variant-based semantic values are enabled
-(@pxref{C++ Variants}),  @xref{Complete Symbols}, for details. In D,
-token constructor works with both "%union" and "%define api.value.type union".
+variant-based semantic values are enabled (@pxref{C++ Variants}), see
+@ref{Complete Symbols}, for details. In D, token constructors work with both
+@samp{%union} and @samp{%define api.value.type union}.
 
 @item Accepted Values:
 Boolean.

examples/d/calc/calc.y

@@ -20,17 +20,14 @@
 %language "D"
 
 %define api.parser.class {Calc}
-%define parse.error detailed
-%define parse.trace
 %define api.push-pull push
 %define api.token.constructor
+%define api.value.type union
+%define parse.error detailed
+%define parse.trace
 
 %locations
 
-%union {
-  int ival;
-}
-
 /* Bison Declarations */
 %token PLUS   "+"
        MINUS  "-"
@@ -39,9 +36,9 @@
        LPAR   "("
        RPAR   ")"
        EOL    "end of line"
-%token <ival> NUM "number"
-%type  <ival> exp
-%printer { yyo.write($$); } <ival>
+%token <int> NUM "number"
+%type  <int> exp
+%printer { yyo.write($$); } <int>
 
 %left "-" "+"
 %left "*" "/"