From 94609aeabcd441caa7c9d41f54166b3f3ede1442 Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sat, 23 May 2020 15:38:07 +1000
Subject: Added Is_Ambiguous function to Parse_Graphs

---
 src/packrat-parse_graphs.adb | 16 ++++++++++++++++
 src/packrat-parse_graphs.ads | 10 +++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

(limited to 'src')

diff --git a/src/packrat-parse_graphs.adb b/src/packrat-parse_graphs.adb
index 16b74dc..c911fb4 100644
--- a/src/packrat-parse_graphs.adb
+++ b/src/packrat-parse_graphs.adb
@@ -232,6 +232,22 @@ package body Packrat.Parse_Graphs is
 
 
 
+    function Is_Ambiguous
+           (Container : in Parse_Graph)
+        return Boolean is
+    begin
+        for N of Container.Nodes loop
+            if Finish_List (Container, N)'Length > 1 then
+                return True;
+            end if;
+        end loop;
+        return False;
+    end Is_Ambiguous;
+
+
+
+
+
     function Vector_To_Array
            (Input : in Type_Vectors.Vector)
         return Array_Type is
diff --git a/src/packrat-parse_graphs.ads b/src/packrat-parse_graphs.ads
index d9cde0b..5663bcf 100644
--- a/src/packrat-parse_graphs.ads
+++ b/src/packrat-parse_graphs.ads
@@ -180,11 +180,11 @@ package Packrat.Parse_Graphs is
 
 
 
-    --  Other things needed here...
-    --  Equal_Subgraph? (in Directed_Graph lib)
-    --  Is_Ambiguous?
-    --  Iterate_Short, Iterate_Long, Iterate_By
-    --  Choosing and Filtering functions for Iterate_By
+    --  Tests whether there are multiple potential finish points for any
+    --  of the nodes in the graph, and hence whether the parse was ambiguous.
+    function Is_Ambiguous
+           (Container : in Parse_Graph)
+        return Boolean;
 
 
 
-- 
cgit