forked from jasder/antlr
291 lines
8.9 KiB
C#
291 lines
8.9 KiB
C#
/*
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* [The "BSD license"]
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* Copyright (c) 2013 Terence Parr
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* Copyright (c) 2013 Sam Harwell
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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using System;
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using System.IO;
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using Antlr4.Runtime;
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using Antlr4.Runtime.Misc;
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using Antlr4.Runtime.Sharpen;
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namespace Antlr4.Runtime
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{
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/// <summary>
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/// Vacuum all input from a
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/// <see cref="System.IO.TextReader"/>
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/// /
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/// <see cref="System.IO.Stream"/>
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/// and then treat it
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/// like a
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/// <c>char[]</c>
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/// buffer. Can also pass in a
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/// <see cref="string"/>
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/// or
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/// <c>char[]</c>
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/// to use.
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/// <p>If you need encoding, pass in stream/reader with correct encoding.</p>
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/// </summary>
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public class AntlrInputStream : ICharStream
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{
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public const int ReadBufferSize = 1024;
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public const int InitialBufferSize = 1024;
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/// <summary>The data being scanned</summary>
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protected internal char[] data;
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/// <summary>How many characters are actually in the buffer</summary>
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protected internal int n;
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/// <summary>0..n-1 index into string of next char</summary>
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protected internal int p = 0;
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/// <summary>What is name or source of this char stream?</summary>
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public string name;
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public AntlrInputStream()
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{
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}
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/// <summary>Copy data in string to a local char array</summary>
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public AntlrInputStream(string input)
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{
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this.data = input.ToCharArray();
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this.n = input.Length;
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}
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/// <summary>This is the preferred constructor for strings as no data is copied</summary>
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public AntlrInputStream(char[] data, int numberOfActualCharsInArray)
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{
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this.data = data;
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this.n = numberOfActualCharsInArray;
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(TextReader r)
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: this(r, InitialBufferSize, ReadBufferSize)
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{
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(TextReader r, int initialSize)
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: this(r, initialSize, ReadBufferSize)
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{
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(TextReader r, int initialSize, int readChunkSize)
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{
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Load(r, initialSize, readChunkSize);
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(Stream input)
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: this(new StreamReader(input), InitialBufferSize)
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{
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(Stream input, int initialSize)
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: this(new StreamReader(input), initialSize)
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{
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}
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/// <exception cref="System.IO.IOException"/>
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public AntlrInputStream(Stream input, int initialSize, int readChunkSize)
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: this(new StreamReader(input), initialSize, readChunkSize)
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{
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}
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/// <exception cref="System.IO.IOException"/>
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public virtual void Load(TextReader r, int size, int readChunkSize)
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{
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if (r == null)
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{
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return;
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}
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data = r.ReadToEnd().ToCharArray();
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n = data.Length;
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}
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/// <summary>
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/// Reset the stream so that it's in the same state it was
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/// when the object was created *except* the data array is not
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/// touched.
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/// </summary>
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/// <remarks>
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/// Reset the stream so that it's in the same state it was
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/// when the object was created *except* the data array is not
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/// touched.
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/// </remarks>
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public virtual void Reset()
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{
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p = 0;
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}
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public virtual void Consume()
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{
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if (p >= n)
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{
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System.Diagnostics.Debug.Assert(La(1) == IntStreamConstants.Eof);
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throw new InvalidOperationException("cannot consume EOF");
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}
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//System.out.println("prev p="+p+", c="+(char)data[p]);
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if (p < n)
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{
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p++;
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}
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}
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//System.out.println("p moves to "+p+" (c='"+(char)data[p]+"')");
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public virtual int La(int i)
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{
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if (i == 0)
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{
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return 0;
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}
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// undefined
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if (i < 0)
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{
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i++;
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// e.g., translate LA(-1) to use offset i=0; then data[p+0-1]
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if ((p + i - 1) < 0)
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{
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return IntStreamConstants.Eof;
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}
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}
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// invalid; no char before first char
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if ((p + i - 1) >= n)
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{
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//System.out.println("char LA("+i+")=EOF; p="+p);
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return IntStreamConstants.Eof;
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}
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//System.out.println("char LA("+i+")="+(char)data[p+i-1]+"; p="+p);
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//System.out.println("LA("+i+"); p="+p+" n="+n+" data.length="+data.length);
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return data[p + i - 1];
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}
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public virtual int Lt(int i)
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{
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return La(i);
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}
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/// <summary>
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/// Return the current input symbol index 0..n where n indicates the
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/// last symbol has been read.
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/// </summary>
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/// <remarks>
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/// Return the current input symbol index 0..n where n indicates the
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/// last symbol has been read. The index is the index of char to
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/// be returned from LA(1).
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/// </remarks>
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public virtual int Index
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{
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get
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{
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return p;
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}
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}
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public virtual int Size
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{
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get
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{
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return n;
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}
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}
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/// <summary>mark/release do nothing; we have entire buffer</summary>
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public virtual int Mark()
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{
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return -1;
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}
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public virtual void Release(int marker)
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{
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}
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/// <summary>
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/// consume() ahead until p==index; can't just set p=index as we must
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/// update line and charPositionInLine.
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/// </summary>
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/// <remarks>
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/// consume() ahead until p==index; can't just set p=index as we must
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/// update line and charPositionInLine. If we seek backwards, just set p
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/// </remarks>
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public virtual void Seek(int index)
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{
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if (index <= p)
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{
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p = index;
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// just jump; don't update stream state (line, ...)
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return;
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}
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// seek forward, consume until p hits index or n (whichever comes first)
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index = Math.Min(index, n);
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while (p < index)
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{
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Consume();
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}
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}
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public virtual string GetText(Interval interval)
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{
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int start = interval.a;
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int stop = interval.b;
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if (stop >= n)
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{
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stop = n - 1;
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}
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int count = stop - start + 1;
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if (start >= n)
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{
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return string.Empty;
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}
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// System.err.println("data: "+Arrays.toString(data)+", n="+n+
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// ", start="+start+
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// ", stop="+stop);
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return new string(data, start, count);
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}
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public virtual string SourceName
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{
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get
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{
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return name;
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}
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}
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public override string ToString()
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{
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return new string(data);
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}
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}
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}
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