antlr/runtime/CSharp/Antlr4.Runtime/Tree/Trees.cs

/*
 * [The "BSD license"]
 *  Copyright (c) 2013 Terence Parr
 *  Copyright (c) 2013 Sam Harwell
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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using System.Collections.Generic;
using System.Text;
using Antlr4.Runtime;
using Antlr4.Runtime.Misc;
using Antlr4.Runtime.Tree;
using Sharpen;

namespace Antlr4.Runtime.Tree
{
    /// <summary>A set of utility routines useful for all kinds of ANTLR trees.</summary>
    /// <remarks>A set of utility routines useful for all kinds of ANTLR trees.</remarks>
    public class Trees
    {
        /// <summary>Print out a whole tree in LISP form.</summary>
        /// <remarks>
        /// Print out a whole tree in LISP form.
        /// <see cref="GetNodeText(ITree, Antlr4.Runtime.Parser)">GetNodeText(ITree, Antlr4.Runtime.Parser)
        ///     </see>
        /// is used on the
        /// node payloads to get the text for the nodes.  Detect
        /// parse trees and extract data appropriately.
        /// </remarks>
        public static string ToStringTree(ITree t)
        {
            return ToStringTree(t, (IList<string>)null);
        }

        /// <summary>Print out a whole tree in LISP form.</summary>
        /// <remarks>
        /// Print out a whole tree in LISP form.
        /// <see cref="GetNodeText(ITree, Antlr4.Runtime.Parser)">GetNodeText(ITree, Antlr4.Runtime.Parser)
        ///     </see>
        /// is used on the
        /// node payloads to get the text for the nodes.  Detect
        /// parse trees and extract data appropriately.
        /// </remarks>
        public static string ToStringTree(ITree t, Parser recog)
        {
            string[] ruleNames = recog != null ? recog.RuleNames : null;
            IList<string> ruleNamesList = ruleNames != null ? Arrays.AsList(ruleNames) : null;
            return ToStringTree(t, ruleNamesList);
        }

        /// <summary>Print out a whole tree in LISP form.</summary>
        /// <remarks>
        /// Print out a whole tree in LISP form.
        /// <see cref="GetNodeText(ITree, Antlr4.Runtime.Parser)">GetNodeText(ITree, Antlr4.Runtime.Parser)
        ///     </see>
        /// is used on the
        /// node payloads to get the text for the nodes.  Detect
        /// parse trees and extract data appropriately.
        /// </remarks>
        public static string ToStringTree(ITree t, IList<string> ruleNames)
        {
            string s = Utils.EscapeWhitespace(GetNodeText(t, ruleNames), false);
            if (t.ChildCount == 0)
            {
                return s;
            }
            StringBuilder buf = new StringBuilder();
            buf.Append("(");
            s = Utils.EscapeWhitespace(GetNodeText(t, ruleNames), false);
            buf.Append(s);
            buf.Append(' ');
            for (int i = 0; i < t.ChildCount; i++)
            {
                if (i > 0)
                {
                    buf.Append(' ');
                }
                buf.Append(ToStringTree(t.GetChild(i), ruleNames));
            }
            buf.Append(")");
            return buf.ToString();
        }

        public static string GetNodeText(ITree t, Parser recog)
        {
            string[] ruleNames = recog != null ? recog.RuleNames : null;
            IList<string> ruleNamesList = ruleNames != null ? Arrays.AsList(ruleNames) : null;
            return GetNodeText(t, ruleNamesList);
        }

        public static string GetNodeText(ITree t, IList<string> ruleNames)
        {
            if (ruleNames != null)
            {
                if (t is IRuleNode)
                {
                    int ruleIndex = ((IRuleNode)t).RuleContext.GetRuleIndex();
                    string ruleName = ruleNames[ruleIndex];
                    return ruleName;
                }
                else
                {
                    if (t is IErrorNode)
                    {
                        return t.ToString();
                    }
                    else
                    {
                        if (t is ITerminalNode)
                        {
                            IToken symbol = ((ITerminalNode)t).Symbol;
                            if (symbol != null)
                            {
                                string s = symbol.Text;
                                return s;
                            }
                        }
                    }
                }
            }
            // no recog for rule names
            object payload = t.Payload;
            if (payload is IToken)
            {
                return ((IToken)payload).Text;
            }
            return t.Payload.ToString();
        }

        /// <summary>Return a list of all ancestors of this node.</summary>
        /// <remarks>
        /// Return a list of all ancestors of this node.  The first node of
        /// list is the root and the last is the parent of this node.
        /// </remarks>
        [return: NotNull]
        public static IList<ITree> GetAncestors(ITree t)
        {
            if (t.Parent == null)
            {
                return Collections.EmptyList<ITree>();
            }
            IList<ITree> ancestors = new List<ITree>();
            t = t.Parent;
            while (t != null)
            {
                ancestors.Insert(0, t);
                // insert at start
                t = t.Parent;
            }
            return ancestors;
        }

        private Trees()
        {
        }
    }
}