bits of markov.js

create trigram

function create(trigram_dict ){ 
	new_string_arr = ["Yo","mama"];
	prevword=trigram_dict [ new_string_arr[new_string_arr.length-2];
	pprevword=new_string_arr[new_string_arr.length-1] ;
	while( typeof( trigram_dict [prevword+' '+pprevword] ) != "undefined" ){
		candidate_words = trigram_dict [ prevword+' '+pprevword ] ; 
		
		//select word randomly out of all candidates
		item = candidate_words[Math.floor( 
 				Math.random() * candidate_words.length)];
		new_string_arr.push(item);
		prevword=trigram_dict [ new_string_arr[new_string_arr.length-2];
		pprevword=new_string_arr[new_string_arr.length-1] ;
	}
	new_str = new_string_arr.join(" ");
	//A brand new sentence
	return new_str ; 
}

making trigrams

trigram_dict = {};
str_arr.forEach( function(e,i){
	sent = e;
word_tokens = str.split(" ");

	word_tokens.forEach( 
		function(e,i){ 
			if( i < 1 ){ return true; }
			if( i == ( word_tokens.length - 1 ) ){ return true; }
			// check if key (previous-word current-word) present
			if( !trigram_dict[ word_tokens[i-1]+' '+e] ){       
				     trigram_dict[ word_tokens[i-1]+' '+e] = [] ; 
			}
			//check if next-word available
			if( typeof(word_tokens[i+1]) != "undefined" ){ 
				trigram_dict[word_tokens[i-1]+' '+e].push(word_tokens[i+1] );
			}
		}
	);

} );