/*  Starshatter OpenSource Distribution
     Copyright (c) 1997-2004, Destroyer Studios LLC.
     All Rights Reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are met:

     * Redistributions of source code must retain the above copyright notice,
        this list of conditions and the following disclaimer.
     * 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.
     * Neither the name "Destroyer Studios" nor the names of its contributors
        may be used to endorse or promote products derived from this software
        without specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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, DATA, OR PROFITS; OR BUSINESS
     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     POSSIBILITY OF SUCH DAMAGE.

     SUBSYSTEM:    Parser
     FILE:         Token.h
     AUTHOR:       John DiCamillo


     OVERVIEW
     ========
     Scanner class definition
*/

#ifndef Token_h
#define Token_h

#include "Text.h"
#include "Dictionary.h"

#pragma warning( disable : 4237)

// +-------------------------------------------------------------------+

class Reader;
class Token;
class Scanner;

// +-------------------------------------------------------------------+

class Token
{
    friend class Scanner;

public:
    // keywords must be alphanumeric identifiers or symbolic identifiers
    enum Types { Undefined, Keyword, AlphaIdent, SymbolicIdent, Comment,
                     IntLiteral, FloatLiteral, StringLiteral, CharLiteral,
                     Dot, Comma, Colon, Semicolon,
                     LParen, RParen, LBracket, RBracket, LBrace, RBrace,
                     EOT, LastTokenType };

    enum Alias { CompoundSeparator   = Dot,
                     ItemSeparator       = Comma,
                     StatementTerminator = Semicolon,
                     TypeIndicator       = Colon,
                     Lambda              = LastTokenType + 1 };

    Token();
    Token(const Token& rhs);
    Token(int t);
    Token(const char* s, int t, int k=0, int l=0, int c=0);
    Token(const Text& s, int t, int k=0, int l=0, int c=0);
    ~Token();

    Token& operator = (const Token& rhs);

    bool     match(const Token& ref) const;

    Text     symbol()   const;
    int      type()     const { return mType;   }
    int      key()      const { return mKey;    }
    int      line()     const { return mLine;   }
    int      column()   const { return mColumn; }

    Text     typestr()  const;

    static Text   describe(const Text& tok);
    static void   addKey(const Text& k, int v);
    static void   addKeys(Dictionary<int>& keys);
    static bool   findKey(const Text& k, int& v);
    static void   comments(const Text& begin, const Text& end);
    static void   altComments(const Text& begin, const Text& end);
    static void   hideComments(bool hide = true) { hidecom = hide; }

    static char   comBeg(unsigned int i) { return combeg[i]; }
    static char   comEnd(unsigned int i) { return comend[i]; }
    static char   altBeg(unsigned int i) { return altbeg[i]; }
    static char   altEnd(unsigned int i) { return altend[i]; }

    static void   close();

protected:
    int      mLength;
    union {
        char  mSymbol[8];
        char* mFullSymbol;
    };
    int      mType;
    int      mKey;
    int      mLine;
    int      mColumn;

    static bool             hidecom;
    static char             combeg[3];
    static char             comend[3];
    static char             altbeg[3];
    static char             altend[3];

    static Dictionary<int> keymap;
};

// +-------------------------------------------------------------------+

class Scanner
{
public:
    Scanner(Reader* r = 0);
    Scanner(const Text&  s);
    Scanner(const Scanner& rhs);
    virtual ~Scanner();

    Scanner& operator = (const Scanner& rhs);

    void           Load(const Text& s);

    enum Need { Demand, Request };
    virtual Token  Get(Need n = Demand);

    void           PutBack()     { index = old_index; line = old_line; }
    int            GetCursor()   { return index;     }
    int            GetLine()     { return line;      }
    void           Reset(int c, int l) { index = old_index = c; line = old_line = l; }
    Token          Best() const  { return best;      }

protected:
    virtual int    GetNumeric();
    virtual bool   IsSymbolic(char c);
    virtual bool   IsAlpha(char c);

    Reader*     reader;
    char*       str;

    const char* p;
    const char* eos;

    size_t      index;
    size_t      old_index;
    Token       best;
    size_t      length;
    size_t      line;
    size_t      old_line;
    size_t      lineStart;
};

#endif // TOKEN_H