Flee

Parsing/Analyzer.cs

@@ -0,0 +1,240 @@
+using System.Collections;
+
+namespace Flee.Parsing
+{
+    [Obsolete("Creates a new parse tree analyzer.")]
+    internal class Analyzer
+    {
+        public Analyzer()
+        {
+        }
+
+        /// <summary>
+        /// Resets this analyzer when the parser is reset for another
+        ///input stream.The default implementation of this method does
+        /// nothing.
+        /// </summary>
+        public virtual void Reset()
+        {
+            // Default implementation does nothing
+        }
+
+        public Node Analyze(Node node)
+        {
+            ParserLogException log = new ParserLogException();
+
+            node = Analyze(node, log);
+            if (log.Count > 0)
+            {
+                throw log;
+            }
+            return node;
+        }
+
+        private Node Analyze(Node node, ParserLogException log)
+        {
+            var errorCount = log.Count;
+            if (node is Production)
+            {
+                var prod = (Production)node;
+                prod = NewProduction(prod.Pattern);
+                try
+                {
+                    Enter(prod);
+                }
+                catch (ParseException e)
+                {
+                    log.AddError(e);
+                }
+                for (int i = 0; i < node.Count; i++)
+                {
+                    try
+                    {
+                        Child(prod, Analyze(node[i], log));
+                    }
+                    catch (ParseException e)
+                    {
+                        log.AddError(e);
+                    }
+                }
+                try
+                {
+                    return Exit(prod);
+                }
+                catch (ParseException e)
+                {
+                    if (errorCount == log.Count)
+                    {
+                        log.AddError(e);
+                    }
+                }
+            }
+            else
+            {
+                node.Values.Clear();
+                try
+                {
+                    Enter(node);
+                }
+                catch (ParseException e)
+                {
+                    log.AddError(e);
+                }
+                try
+                {
+                    return Exit(node);
+                }
+                catch (ParseException e)
+                {
+                    if (errorCount == log.Count)
+                    {
+                        log.AddError(e);
+                    }
+                }
+            }
+            return null;
+        }
+
+        public virtual Production NewProduction(ProductionPattern pattern)
+        {
+            return new Production(pattern);
+        }
+
+        public virtual void Enter(Node node)
+        {
+        }
+
+        public virtual Node Exit(Node node)
+        {
+            return node;
+        }
+
+        public virtual void Child(Production node, Node child)
+        {
+            node.AddChild(child);
+        }
+
+        protected Node GetChildAt(Node node, int pos)
+        {
+            if (node == null)
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "attempt to read 'null' parse tree node",
+                    -1,
+                    -1);
+            }
+            var child = node[pos];
+            if (child == null)
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "node '" + node.Name + "' has no child at " +
+                    "position " + pos,
+                    node.StartLine,
+                    node.StartColumn);
+            }
+            return child;
+        }
+
+        protected Node GetChildWithId(Node node, int id)
+        {
+            if (node == null)
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "attempt to read 'null' parse tree node",
+                    -1,
+                    -1);
+            }
+            for (int i = 0; i < node.Count; i++)
+            {
+                var child = node[i];
+                if (child != null && child.Id == id)
+                {
+                    return child;
+                }
+            }
+            throw new ParseException(
+                ParseException.ErrorType.INTERNAL,
+                "node '" + node.Name + "' has no child with id " + id,
+                node.StartLine,
+                node.StartColumn);
+        }
+
+        protected object GetValue(Node node, int pos)
+        {
+            if (node == null)
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "attempt to read 'null' parse tree node",
+                    -1,
+                    -1);
+            }
+            var value = node.Values[pos];
+            if (value == null)
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "node '" + node.Name + "' has no value at " +
+                    "position " + pos,
+                    node.StartLine,
+                    node.StartColumn);
+            }
+            return value;
+        }
+
+        protected int GetIntValue(Node node, int pos)
+        {
+            var value = GetValue(node, pos);
+            if (value is int)
+            {
+                return (int)value;
+            }
+            else
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "node '" + node.Name + "' has no integer value " +
+                    "at position " + pos,
+                    node.StartLine,
+                    node.StartColumn);
+            }
+        }
+       
+        protected string GetStringValue(Node node, int pos)
+        {
+            var value = GetValue(node, pos);
+            if (value is string)
+            {
+                return (string)value;
+            }
+            else
+            {
+                throw new ParseException(
+                    ParseException.ErrorType.INTERNAL,
+                    "node '" + node.Name + "' has no string value " +
+                    "at position " + pos,
+                    node.StartLine,
+                    node.StartColumn);
+            }
+        }
+
+        protected ArrayList GetChildValues(Node node)
+        {
+            ArrayList result = new ArrayList();
+
+            for (int i = 0; i < node.Count; i++)
+            {
+                var child = node[i];
+                var values = child.Values;
+                if (values != null)
+                {
+                    result.AddRange(values);
+                }
+            }
+            return result;
+        }
+    }
+}