//string2.cpp
//methods for class String

#include "string2.h"
#include <iostream.h>
#include <string.h>
#include <assert.h>

const int Max = 256;

//default constructor
String::String() {
	length = 0;
	val = new char;
	assert(val);
	*val = '\0';
}

//conversion constructor from a C string
String::String(char *s) {
	assert(s);
	length = strlen(s);
	val = new char[length+1];
	assert(val);
	strcpy(val, s);
}

//destructor
String::~String() {
	delete [] val;
}

//returns the length of string
int String::getlength() {
	return length;
}

//creates a copy of string s
void String::copy(String *s) {
	assert(s);
	length = s->length;
	delete [] val;
	val = new char[length+1];
	assert(val);
	strcpy(val, s->val);
}

//concatenates two strings
void String::cat(String *s) {
	assert(s);
	char *temp;

	length += s->length;
	temp = new char[length+1];
	assert(temp);
	strcpy(temp, val);
	strcat(temp, s->val);
	delete [] val;
	val = temp;
}

//returns a positive integer if the first String is greater than the second;
//returns a negative integer if the first is less than second;
//returns 0 if they are equal
int String::compare(String *s) {
	return strcmp(val, s->val);
}

//returns pointer to nth element of string, if n is outside the
//length of string, returns NULL
char* String::at(int n) {
	if (n > length-1 || n < 0)
		return NULL;
	return &val[n];
}

//prints out string
void String::print() {
	cout<<val;
}

//reads in string from stdin, if line is longer than Max-1 characters,
//it is truncated
void String::read() {
	char temp[Max], ch;

	cin.get(temp, Max);
		for(;;)
			if (!cin.get(ch) || ch == '\n')
				break;
	length = strlen(temp);
	val = new char[length+1];
	assert(val);
	strcpy(val, temp);
}