Changeset 290

Timestamp:

05/19/08 22:00:34 (8 months ago)

Author:

chris

Message:

Fix infinite loop caused by recursive rules.

Files:

• lex/trunk/src/com/qwirx/lex/parser/Edge.java (modified) (1 diff)
• lex/trunk/src/com/qwirx/lex/parser/MorphEdge.java (modified) (1 diff)
• lex/trunk/src/com/qwirx/lex/parser/Parser.java (modified) (1 diff)
• lex/trunk/src/com/qwirx/lex/parser/Rule.java (modified) (2 diffs)
• lex/trunk/src/com/qwirx/lex/parser/RuleEdge.java (modified) (1 diff)
• lex/trunk/src/com/qwirx/lex/parser/WordEdge.java (modified) (1 diff)
• lex/trunk/test/com/qwirx/lex/ParserTest.java (modified) (1 diff)

lex/trunk/src/com/qwirx/lex/parser/Edge.java

@@ -41 +41 @@
-    boolean isAt(int pos);
-    boolean includes(Edge other);
+    boolean uses(Rule rule);
-    TreeNode toTree();
-    String getHtmlLabel();

lex/trunk/src/com/qwirx/lex/parser/MorphEdge.java

@@ -146 +146 @@
-    }
-    
+    public boolean uses(Rule rule)
+    {
+        return false;
+    }
+    
-    public String getHtmlLabel()
-    {

lex/trunk/src/com/qwirx/lex/parser/Parser.java

@@ -90 +90 @@
-                }
-                                */
+                
+                // Don't re-use a rule that's already been used
+                // somewhere in this edge. That could lead to
+                // infinite recursion and should not be necessary.
-
-                Rule rule = rules[r];
-
-
+
+
+
+
+
+
-                        }
-                }

lex/trunk/src/com/qwirx/lex/parser/Rule.java

@@ -688 +688 @@
-    }
-
-
+<Edge>
-    {
-        boolean foundUnfinishedPart = false;
@@ -719 +719 @@
-        // and we should be ready to create a new edge.
-        
-:
-
+
+(all parts optional and skipped): 
-        
-        int numEdges = 0;

lex/trunk/src/com/qwirx/lex/parser/RuleEdge.java

@@ -459 +459 @@
-        return false;
-    }
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-    public void getLeavesInto(List leaves)
-    {

lex/trunk/src/com/qwirx/lex/parser/WordEdge.java

@@ -139 +139 @@
-    }
-    
+    public boolean uses(Rule rule)
+    {
+        return false;
+    }
+    
-    public String getHtmlLabel()
-    {

lex/trunk/test/com/qwirx/lex/ParserTest.java

@@ -2006 +2006 @@
-    }
-
+    public void testInfiniteLoop() throws Exception 
+    {
+        Rule[] rules = new Rule[]{
+                Rule.makeFromString2(1, "C", "{B}"),
+                Rule.makeFromString2(2, "B", "x"),
+                Rule.makeFromString2(3, "B", "{A}"),
+                Rule.makeFromString2(4, "A", "{B}"),
+        };
+        
+        Parser p = new Parser(rules);
+        p.setVerbose(true);
+
+        List results = p.parseFor("x", "C");
+        assertEquals(2, results.size());
+
+        Edge C = (Edge)(results.get(1));
+        assertEquals("C", C.symbol());
+        assertEquals("B", C.part(0).symbol());
+        assertEquals("x", C.part(0).part(0).symbol());
+
+        C = (Edge)(results.get(0));
+        assertEquals("C", C.symbol());
+        assertEquals("B", C.part(0).symbol());
+        assertEquals("A", C.part(0).part(0).symbol());
+        assertEquals("B", C.part(0).part(0).part(0).symbol());
+        assertEquals("x", C.part(0).part(0).part(0).part(0).symbol());
+    }
+
-        public static void main(String[] args) 
-    {