Support parametric types.

There are two issues to handle: first scanning nested angle bracket pairs
to support types such as std::pair< std::string, std::list<std::string> > >.

Another issue is to address idiosyncracies of C++: do not glue two closing
angle brackets together (otherwise it's operator>>), and avoid sticking
blindly a TYPE to the opening <, as it can result in '<:' which is a
digraph for '['.

	* src/scan-gram.l (brace_level): Rename as...
	(nesting): this.
	(SC_TAG): New.
	Implement support for complex tags.
	(tag): Accept \n, but not <.
	* data/lalr1.cc (b4_symbol_value, b4_symbol_value_template)
	(b4_symbol_variant): Leave space around types as parameters.
	* examples/variant.yy: Use nested template types and leading ::.
	* src/parse-gram.y (TYPE, TYPE_TAG_ANY, TYPE_TAG_NONE, type.opt):
	Rename as...
	(TAG, TAG_ANY, TAG_NONE, tag.opt): these.
	* tests/c++.at: Test parametric types.

1 files changed, 5 insertions, 4 deletions

diff --git a/examples/variant.yy b/examples/variant.yy
index 016c4b2a..fe5dce0f 100644
--- a/examples/variant.yy
+++ b/examples/variant.yy
@@ -46,13 +46,14 @@ typedef std::list<std::string> strings_type;
   }
 }
 
-%token <std::string> TEXT;
+%token <::std::string> TEXT;
 %token <int> NUMBER;
-%printer { debug_stream () << $$; } <int> <std::string> <strings_type>;
+%printer { debug_stream () << $$; }
+   <int> <::std::string> <::std::list<std::string>>;
 %token END_OF_FILE 0;
 
-%type <std::string> item;
-%type <strings_type> list;
+%type <::std::string> item;
+%type <::std::list<std::string>> list;
 
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