stringProcessing.h

//
// Created by anvia on 1/31/2018.
//

#ifndef EECS398_SEARCH_STRINGPROCESSING_H
#define EECS398_SEARCH_STRINGPROCESSING_H

#include <string>
#include <unordered_map>
#include <vector>
#include <set>
#include <iterator>

using namespace std;

/**
 * Set of stopwords
 */
set< string > stopWords = { "a", "all", "an", "and", "any", "are", "as", "at", "be", "been", "but", "by", "few", "from",
                            "for", "have", "he", "her", "here", "him", "his", "how",
                            "i", "in", "is", "it", "its", "many ", "me", "my", "none", "of", "on", "or", "our", "she",
                            "some", "the", "their", "them", "there", "they", "that",
                            "this", "to", "us", "was", "what", "when", "where", "which", "who", "why", "will", "with",
                            "you", "your" };
/**
 * Finds the needle in the haystack
 * returns position of first match
 * @param haystack
 * @param needle
 * @return string::iterator
 */
string::iterator findStr (string needle, string haystack )
	{

	auto beginNeedle = needle.begin ( );
	auto beginHaystack = haystack.begin();

	while ( *beginHaystack != '\0' )
		{
		//keep looking for instance of a match
		if ( *beginHaystack != *beginNeedle )
			{
			++beginHaystack;
			}

		else if ( *beginHaystack == *beginNeedle )
			{
			/* want to keep the original iterator where it is so it
				can return the beginning of the matched word if found */
			auto temp = beginHaystack;
			while ( *temp == *beginNeedle )
				{
				++temp;
				++beginNeedle;
				//if it hits the end of the needleing, it signifies an exact match
				if ( *beginNeedle == '\0' )
					{
					//this is pointing at the beginning of the match
					return beginHaystack;
					}

				}
			//need to reset because still has to search rest of the string for a match
			beginNeedle = needle.begin ( );
			//sets the original text pointer to where the last search left off
			beginHaystack = temp;
			}

		else
			{
			//DO NOTHING
			}
		}

	return beginHaystack;

	}

/**
 * Finds the next position of the needle in the string
 * @param needle
 * @param pointer
 * @return string::iterator
 */
string::iterator findNext (string needle, string::iterator haystackPointer )
	{
	auto beginNeedle = needle.begin ( );
	auto beginHaystack = haystackPointer;
	while ( *beginHaystack != '\0' )
		{
		//keep looking for instance of a match
		if ( *beginHaystack != *beginNeedle )
			{
			++beginHaystack;
			}

		else if ( *beginHaystack == *beginNeedle )
			{
			/* want to keep the original iterator where it is so it
				can return the beginning of the matched word if found */
			auto temp = beginHaystack;
			while ( *temp == *beginNeedle )
				{
				++temp;
				++beginNeedle;
				//if it hits the end of the needleing, it signifies an exact match
				if ( *beginNeedle == '\0' )
					{
					//this is pointing at the beginning of the match
					return beginHaystack;
					}

				}
			//need to reset because still has to search rest of the string for a match
			beginNeedle = needle.begin ( );
			//sets the original text pointer to where the last search left off
			beginHaystack = temp;
			}

		else
			{
			//DO NOTHING
			}
		}

	return beginHaystack;
	}


/**
 * Returns a vector of strings from @originalText, split by @delim
 * @param originalText
 * @param delim
 * @return
 */
vector< string > splitStr ( string originalText, char delim )
	{
	vector< string > splitWords;
	auto begin = originalText.begin ( );

	while ( *begin != '\0' )
		{
		string word = "";
		while ( *begin != delim && *begin != '\0' )
			{
			word += *begin;
			++begin;
			}

		splitWords.push_back ( word );
		++begin;
		}

	return splitWords;

	}
/**
 * Returns true if @word is a stopword
 * @param word
 * @return
 */
bool isStopWord ( string word )
	{
	return ( stopWords.find ( word ) != stopWords.end ( ) );

	}
/**
 * Returns lowercase @word
 * @param word
 * @return
 */
string toLower ( string word )
	{
	auto iter = word.begin ( );
	string lowerWord = "";
	while ( *iter != '\0' )
		{
		if ( *iter >= 'A' && *iter <= 'Z' )
			{
			lowerWord += ( *iter + 32 );
			}

		else
			{
			lowerWord += *iter;
			}
		++iter;
		}

	return lowerWord;
	}

//TODO
/**
 * Returns stemmed @word
 * @param word
 * @return
 */
string stemWord(string word)
	{
	return "";
	}

#endif //EECS398_SEARCH_STRINGPROCESSING_H