// CIS-62 substring class

#ifndef _CIS62_SUBSTRING_H_INCLUDED_
#define _CIS62_SUBSTRING_H_INCLUDED_

#include <string>

class substring {
    std::string& m_str;
public:
    // Constructor that takes a reference to a string:
    substring( std::string& str );

    // Constructor that takes string reference, beginning, and ending positions
    substring( std::string& str, size_t pos_begin, size_t pos_end );

    // Return copy of the substring as std::string object
    std::string str() const;

    // Return substring size
    size_t size() const;

    // Return beginning position 
    size_t begin() const;

    // Return ending position
    size_t end() const;

    // Set beginning position 
    void begin( size_t pos );

    // Set ending position
    void end( size_t pos );

    // The string content is set to an empty string
    void clear();

    // Replace substring with str
    substring& replace( std::string const& str );

    // Fill substring with a particular character
    substring& fill( char ch );

    // Insert str at the specified position:
    substring& insert( std::string const& str, size_t pos );

    // Convert substring to UPPER CASE
    substring& toupper();

    // Convert substring to lower case
    substring& tolower();

    // Search for a new substring starting at the specified position:
    size_t search( const std::string& str, size_t pos );

    // The string content is set to the size of entire string
    void expand();

    // Equality test between two substrings
    bool equals_to( substring const& other ) const;

    // Equality test between substring and std::string
    bool equals_to( std::string const& str ) const;

    // Merge with another substring
    substring& merge( substring const& other );

    // Swap with another substring
    void swap( substring& other );

    // Prepare substring for parsing
    substring& parse();

    // Test if substring is alphabetic
    substring& isalpha();

    // Test if substring is upper case
    substring& isupper();

    // Test if substring is lower case
    substring& islower();

    // Test if substring is digit
    substring& isdigit();

    // Test if substring is alphabetic or digit
    substring& isalnum();

    // Test if substring is blank, tab, newline, return, formfeed, or vertical tab 
    substring& isspace();

    // Test if substring is matches text specified by str 
    substring& isstr( const std::string& str );

    // Test if substring is empty
    substring& isempty();

    // Return beginning position 
    bool succeeded() const;

    // Return matching substring
    substring match() const;

    // Undo changes caused by parsing
    substring& unparse();
};

#endif // _CIS62_SUBSTRING_H_INCLUDED_