Adding first() & last() ops to the grammar.

libwccl/parser/grammar.g

@@ -53,6 +53,8 @@ header {
 	#include <libwccl/ops/functions/tset/getsymbolsinrange.h>
 
 	#include <libwccl/ops/functions/position/relativeposition.h>
+	#include <libwccl/ops/functions/position/lasttoken.h>
+	#include <libwccl/ops/functions/position/firsttoken.h>
 
 	#include <libwccl/ops/functions/bool/iterations/only.h>
 	#include <libwccl/ops/functions/bool/iterations/atleast.h>
@@ -830,8 +832,10 @@ position_operator
 	[const Corpus2::Tagset& tagset, Variables& vars]
 	returns [boost::shared_ptr<Function<Position> > ret]
 	: 
-	( ret = position_var_val   [vars]
-	| ret = position_condition [tagset, vars]
+	( ret = position_var_val     [vars]
+	| ret = position_condition   [tagset, vars]
+	| ret = position_first_token [tagset, vars]
+	| ret = position_last_token  [tagset, vars]
 	| LPAREN ret = position_operator [tagset, vars] RPAREN
 	) 
 	( // if there is SIGNED_INT after the position, it is actually a relative position
@@ -880,6 +884,32 @@ position_condition
 		}
 ;
 
+// ----------------------------------------------------------------------------
+// Taking position of a first token in a match
+// first(Match)
+position_first_token [const Corpus2::Tagset& tagset, Variables& vars]
+	returns [boost::shared_ptr<Function<Position> > ret]
+{
+	boost::shared_ptr<Function<Match> > m;
+}
+	: "first" LPAREN m = match_fit [tagset, vars] RPAREN {
+		ret.reset(new FirstToken(m));
+	}
+;
+
+// ----------------------------------------------------------------------------
+// Taking position of a first token in a match
+// last(Match)
+position_last_token [const Corpus2::Tagset& tagset, Variables& vars]
+	returns [boost::shared_ptr<Function<Position> > ret]
+{
+	boost::shared_ptr<Function<Match> > m;
+}
+	: "last" LPAREN m = match_fit [tagset, vars] RPAREN {
+		ret.reset(new LastToken(m));
+	}
+;
+
 ///////////////////////////////////////////////////////////////////////////////
 // Stiring operator
 // Returns boost::shared_ptr<Function<StrSet> >